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1 \input texinfo @c -*-texinfo-*-
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2 @c %**start of header
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3 @setfilename ../info/standards.info
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4 @settitle GNU Coding Standards
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5 @c In GNU Emacs, this date is automagically updated when this file is
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6 @c saved, but in XEmacs you must set it when synching:
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7 @set lastupdate February 21, 2001
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8 @c %**end of header
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9
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10 @ifinfo
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11 @format
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12 START-INFO-DIR-ENTRY
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13 * Standards: (standards). GNU coding standards.
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14 END-INFO-DIR-ENTRY
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15 @end format
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16 @end ifinfo
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17
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18 @c @setchapternewpage odd
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19 @setchapternewpage off
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20
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21 @c Put everything in one index (arbitrarily chosen to be the concept index).
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22 @syncodeindex fn cp
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23 @syncodeindex ky cp
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24 @syncodeindex pg cp
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25 @syncodeindex vr cp
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26
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27 @c This is used by a cross ref in make-stds.texi
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28 @set CODESTD 1
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29 @iftex
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30 @set CHAPTER chapter
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31 @end iftex
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32 @ifinfo
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33 @set CHAPTER node
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34 @end ifinfo
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35
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36 @ifinfo
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37 GNU Coding Standards
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38 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
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39
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40 Permission is granted to make and distribute verbatim copies of
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41 this manual provided the copyright notice and this permission notice
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42 are preserved on all copies.
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43
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44 @ignore
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45 Permission is granted to process this file through TeX and print the
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46 results, provided the printed document carries copying permission
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47 notice identical to this one except for the removal of this paragraph
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48 (this paragraph not being relevant to the printed manual).
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49 @end ignore
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50
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51 Permission is granted to copy and distribute modified versions of this
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52 manual under the conditions for verbatim copying, provided that the entire
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53 resulting derived work is distributed under the terms of a permission
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54 notice identical to this one.
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55
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56 Permission is granted to copy and distribute translations of this manual
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57 into another language, under the above conditions for modified versions,
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58 except that this permission notice may be stated in a translation approved
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59 by the Free Software Foundation.
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60 @end ifinfo
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61
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62 @titlepage
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63 @title GNU Coding Standards
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64 @author Richard Stallman
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65 @author last updated @value{lastupdate}
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66 @page
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67
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68 @vskip 0pt plus 1filll
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69 Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
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70
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71 Permission is granted to make and distribute verbatim copies of
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72 this manual provided the copyright notice and this permission notice
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73 are preserved on all copies.
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74
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75 Permission is granted to copy and distribute modified versions of this
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76 manual under the conditions for verbatim copying, provided that the entire
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77 resulting derived work is distributed under the terms of a permission
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78 notice identical to this one.
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79
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80 Permission is granted to copy and distribute translations of this manual
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81 into another language, under the above conditions for modified versions,
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82 except that this permission notice may be stated in a translation approved
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83 by the Free Software Foundation.
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84 @end titlepage
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85
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86 @ifinfo
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87 @node Top, Preface, (dir), (dir)
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88 @top Version
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89
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90 Last updated @value{lastupdate}.
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91 @end ifinfo
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92
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93 @menu
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94 * Preface:: About the GNU Coding Standards
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95 * Legal Issues:: Keeping Free Software Free
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96 * Design Advice:: General Program Design
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97 * Program Behavior:: Program Behavior for All Programs
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98 * Writing C:: Making The Best Use of C
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99 * Documentation:: Documenting Programs
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100 * Managing Releases:: The Release Process
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101 * References:: References to Non-Free Software or Documentation
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102 * Index::
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103 @end menu
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104
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105 @node Preface
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106 @chapter About the GNU Coding Standards
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107
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108 The GNU Coding Standards were written by Richard Stallman and other GNU
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109 Project volunteers. Their purpose is to make the GNU system clean,
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110 consistent, and easy to install. This document can also be read as a
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111 guide to writing portable, robust and reliable programs. It focuses on
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112 programs written in C, but many of the rules and principles are useful
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113 even if you write in another programming language. The rules often
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114 state reasons for writing in a certain way.
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115
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116 Corrections or suggestions for this document should be sent to
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117 @email{bug-standards@@gnu.org}. If you make a suggestion, please include a
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118 suggested new wording for it; our time is limited. We prefer a context
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119 diff to the @file{standards.texi} or @file{make-stds.texi} files, but if
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120 you don't have those files, please mail your suggestion anyway.
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121
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122 This release of the GNU Coding Standards was last updated
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123 @value{lastupdate}.
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124
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125 @cindex where to obtain @code{standards.texi}
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126 @cindex downloading this manual
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127 If you did not obtain this file directly from the GNU project and
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128 recently, please check for a newer version. You can ftp the GNU Coding
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129 Standards from any GNU FTP host in the directory
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130 @file{/pub/gnu/standards/}. The GNU Coding Standards are available
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131 there in several different formats: @file{standards.text},
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132 @file{standards.texi}, @file{standards.info}, and @file{standards.dvi}.
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133 The GNU Coding Standards are also available on the GNU World Wide Web
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134 server: @uref{http://www.gnu.org/prep/standards_toc.html}.
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135
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136 @node Legal Issues
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137 @chapter Keeping Free Software Free
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138 @cindex legal aspects
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139
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140 This @value{CHAPTER} discusses how you can make sure that GNU software
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141 avoids legal difficulties, and other related issues.
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142
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143 @menu
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144 * Reading Non-Free Code:: Referring to Proprietary Programs
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145 * Contributions:: Accepting Contributions
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146 * Trademarks:: How We Deal with Trademark Issues
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147 @end menu
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148
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149 @node Reading Non-Free Code
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150 @section Referring to Proprietary Programs
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151 @cindex proprietary programs
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152 @cindex avoiding proprietary code
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153
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154 Don't in any circumstances refer to Unix source code for or during
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155 your work on GNU! (Or to any other proprietary programs.)
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156
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157 If you have a vague recollection of the internals of a Unix program,
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158 this does not absolutely mean you can't write an imitation of it, but
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159 do try to organize the imitation internally along different lines,
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160 because this is likely to make the details of the Unix version
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161 irrelevant and dissimilar to your results.
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162
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163 For example, Unix utilities were generally optimized to minimize
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164 memory use; if you go for speed instead, your program will be very
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165 different. You could keep the entire input file in core and scan it
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166 there instead of using stdio. Use a smarter algorithm discovered more
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167 recently than the Unix program. Eliminate use of temporary files. Do
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168 it in one pass instead of two (we did this in the assembler).
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169
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170 Or, on the contrary, emphasize simplicity instead of speed. For some
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171 applications, the speed of today's computers makes simpler algorithms
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172 adequate.
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173
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174 Or go for generality. For example, Unix programs often have static
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175 tables or fixed-size strings, which make for arbitrary limits; use
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176 dynamic allocation instead. Make sure your program handles NULs and
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177 other funny characters in the input files. Add a programming language
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178 for extensibility and write part of the program in that language.
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179
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180 Or turn some parts of the program into independently usable libraries.
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181 Or use a simple garbage collector instead of tracking precisely when
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182 to free memory, or use a new GNU facility such as obstacks.
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183
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184 @node Contributions
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185 @section Accepting Contributions
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186 @cindex legal papers
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187 @cindex accepting contributions
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188
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189 If the program you are working on is copyrighted by the Free Software
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190 Foundation, then when someone else sends you a piece of code to add to
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191 the program, we need legal papers to use it---just as we asked you to
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192 sign papers initially. @emph{Each} person who makes a nontrivial
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193 contribution to a program must sign some sort of legal papers in order
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194 for us to have clear title to the program; the main author alone is not
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195 enough.
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196
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197 So, before adding in any contributions from other people, please tell
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198 us, so we can arrange to get the papers. Then wait until we tell you
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199 that we have received the signed papers, before you actually use the
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200 contribution.
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201
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202 This applies both before you release the program and afterward. If
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203 you receive diffs to fix a bug, and they make significant changes, we
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204 need legal papers for that change.
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205
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206 This also applies to comments and documentation files. For copyright
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207 law, comments and code are just text. Copyright applies to all kinds of
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208 text, so we need legal papers for all kinds.
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209
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210 We know it is frustrating to ask for legal papers; it's frustrating for
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211 us as well. But if you don't wait, you are going out on a limb---for
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212 example, what if the contributor's employer won't sign a disclaimer?
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213 You might have to take that code out again!
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214
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215 You don't need papers for changes of a few lines here or there, since
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216 they are not significant for copyright purposes. Also, you don't need
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217 papers if all you get from the suggestion is some ideas, not actual code
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218 which you use. For example, if someone send you one implementation, but
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219 you write a different implementation of the same idea, you don't need to
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220 get papers.
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221
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222 The very worst thing is if you forget to tell us about the other
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223 contributor. We could be very embarrassed in court some day as a
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224 result.
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225
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226 We have more detailed advice for maintainers of programs; if you have
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227 reached the stage of actually maintaining a program for GNU (whether
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228 released or not), please ask us for a copy.
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229
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230 @node Trademarks
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231 @section Trademarks
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232 @cindex trademarks
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233
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234 Please do not include any trademark acknowledgements in GNU software
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235 packages or documentation.
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236
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237 Trademark acknowledgements are the statements that such-and-such is a
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238 trademark of so-and-so. The GNU Project has no objection to the basic
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239 idea of trademarks, but these acknowledgements feel like kowtowing, so
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240 we don't use them. There is no legal requirement for them.
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241
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242 What is legally required, as regards other people's trademarks, is to
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243 avoid using them in ways which a reader might read as naming or labeling
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244 our own programs or activities. For example, since ``Objective C'' is
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245 (or at least was) a trademark, we made sure to say that we provide a
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246 ``compiler for the Objective C language'' rather than an ``Objective C
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247 compiler''. The latter is meant to be short for the former, but it does
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248 not explicitly state the relationship, so it could be misinterpreted as
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249 using ``Objective C'' as a label for the compiler rather than for the
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250 language.
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251
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252 @node Design Advice
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253 @chapter General Program Design
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254 @cindex program design
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255
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256 This @value{CHAPTER} discusses some of the issues you should take into
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257 account when designing your program.
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258
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259 @c Standard or ANSI C
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260 @c
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261 @c In 1989 the American National Standards Institute (ANSI) standardized
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262 @c C as standard X3.159-1989. In December of that year the
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263 @c International Standards Organization ISO adopted the ANSI C standard
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264 @c making minor changes. In 1990 ANSI then re-adopted ISO standard
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265 @c C. This version of C is known as either ANSI C or Standard C.
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266
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267 @c A major revision of the C Standard appeared in 1999.
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268
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269 @menu
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270 * Source Language:: Which languges to use.
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271 * Compatibility:: Compatibility with other implementations
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272 * Using Extensions:: Using non-standard features
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273 * Standard C:: Using Standard C features
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274 @end menu
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275
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276 @node Source Language
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277 @section Which Languages to Use
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278 @cindex programming languges
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279
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280 When you want to use a language that gets compiled and runs at high
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281 speed, the best language to use is C. Using another language is like
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282 using a non-standard feature: it will cause trouble for users. Even if
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283 GCC supports the other language, users may find it inconvenient to have
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284 to install the compiler for that other language in order to build your
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285 program. For example, if you write your program in C++, people will
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286 have to install the GNU C++ compiler in order to compile your program.
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287
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288 C has one other advantage over C++ and other compiled languages: more
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289 people know C, so more people will find it easy to read and modify the
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290 program if it is written in C.
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291
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292 So in general it is much better to use C, rather than the
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293 comparable alternatives.
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294
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295 But there are two exceptions to that conclusion:
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296
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297 @itemize @bullet
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298 @item
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299 It is no problem to use another language to write a tool specifically
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300 intended for use with that language. That is because the only people
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301 who want to build the tool will be those who have installed the other
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302 language anyway.
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303
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304 @item
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305 If an application is of interest only to a narrow part of the community,
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306 then the question of which language it is written in has less effect on
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307 other people, so you may as well please yourself.
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308 @end itemize
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309
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310 Many programs are designed to be extensible: they include an interpreter
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311 for a language that is higher level than C. Often much of the program
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312 is written in that language, too. The Emacs editor pioneered this
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313 technique.
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314
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315 @cindex GUILE
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316 The standard extensibility interpreter for GNU software is GUILE, which
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317 implements the language Scheme (an especially clean and simple dialect
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318 of Lisp). @uref{http://www.gnu.org/software/guile/}. We don't reject
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319 programs written in other ``scripting languages'' such as Perl and
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320 Python, but using GUILE is very important for the overall consistency of
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321 the GNU system.
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322
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323 @node Compatibility
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324 @section Compatibility with Other Implementations
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325 @cindex compatibility with C and @sc{posix} standards
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326 @cindex @sc{posix} compatibility
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327
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328 With occasional exceptions, utility programs and libraries for GNU
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329 should be upward compatible with those in Berkeley Unix, and upward
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330 compatible with Standard C if Standard C specifies their
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331 behavior, and upward compatible with @sc{posix} if @sc{posix} specifies
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332 their behavior.
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333
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334 When these standards conflict, it is useful to offer compatibility
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335 modes for each of them.
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336
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462
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337 @cindex options for compatibility
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338 Standard C and @sc{posix} prohibit many kinds of extensions. Feel
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339 free to make the extensions anyway, and include a @samp{--ansi},
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340 @samp{--posix}, or @samp{--compatible} option to turn them off.
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341 However, if the extension has a significant chance of breaking any real
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342 programs or scripts, then it is not really upward compatible. So you
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343 should try to redesign its interface to make it upward compatible.
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344
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345 @cindex @code{POSIXLY_CORRECT}, environment variable
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346 Many GNU programs suppress extensions that conflict with @sc{posix} if the
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347 environment variable @code{POSIXLY_CORRECT} is defined (even if it is
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348 defined with a null value). Please make your program recognize this
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349 variable if appropriate.
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350
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351 When a feature is used only by users (not by programs or command
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352 files), and it is done poorly in Unix, feel free to replace it
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353 completely with something totally different and better. (For example,
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354 @code{vi} is replaced with Emacs.) But it is nice to offer a compatible
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355 feature as well. (There is a free @code{vi} clone, so we offer it.)
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356
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462
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357 Additional useful features are welcome regardless of whether
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358 there is any precedent for them.
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359
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360 @node Using Extensions
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361 @section Using Non-standard Features
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462
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362 @cindex non-standard extensions
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428
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363
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364 Many GNU facilities that already exist support a number of convenient
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365 extensions over the comparable Unix facilities. Whether to use these
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366 extensions in implementing your program is a difficult question.
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367
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368 On the one hand, using the extensions can make a cleaner program.
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369 On the other hand, people will not be able to build the program
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370 unless the other GNU tools are available. This might cause the
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371 program to work on fewer kinds of machines.
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372
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373 With some extensions, it might be easy to provide both alternatives.
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374 For example, you can define functions with a ``keyword'' @code{INLINE}
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375 and define that as a macro to expand into either @code{inline} or
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376 nothing, depending on the compiler.
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377
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378 In general, perhaps it is best not to use the extensions if you can
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379 straightforwardly do without them, but to use the extensions if they
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380 are a big improvement.
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381
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382 An exception to this rule are the large, established programs (such as
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462
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383 Emacs) which run on a great variety of systems. Using GNU extensions in
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384 such programs would make many users unhappy, so we don't do that.
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385
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386 Another exception is for programs that are used as part of compilation:
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387 anything that must be compiled with other compilers in order to
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388 bootstrap the GNU compilation facilities. If these require the GNU
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389 compiler, then no one can compile them without having them installed
|
|
|
390 already. That would be extremely troublesome in certain cases.
|
|
|
391
|
|
|
392 @node Standard C
|
|
|
393 @section Standard C and Pre-Standard C
|
|
|
394 @cindex @sc{ansi} C standard
|
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|
395
|
|
|
396 1989 Standard C is widespread enough now that it is ok to use its
|
|
|
397 features in new programs. There is one exception: do not ever use the
|
|
|
398 ``trigraph'' feature of Standard C.
|
|
|
399
|
|
|
400 1999 Standard C is not widespread yet, so please do not require its
|
|
|
401 features in programs. It is ok to use its features if they are present.
|
|
|
402
|
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|
403 However, it is easy to support pre-standard compilers in most programs,
|
|
|
404 so if you know how to do that, feel free. If a program you are
|
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|
405 maintaining has such support, you should try to keep it working.
|
|
|
406
|
|
|
407 @cindex function prototypes
|
|
|
408 To support pre-standard C, instead of writing function definitions in
|
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|
409 standard prototype form,
|
|
428
|
410
|
|
|
411 @example
|
|
|
412 int
|
|
|
413 foo (int x, int y)
|
|
|
414 @dots{}
|
|
|
415 @end example
|
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|
416
|
|
|
417 @noindent
|
|
462
|
418 write the definition in pre-standard style like this,
|
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428
|
419
|
|
|
420 @example
|
|
|
421 int
|
|
|
422 foo (x, y)
|
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|
423 int x, y;
|
|
|
424 @dots{}
|
|
|
425 @end example
|
|
|
426
|
|
|
427 @noindent
|
|
|
428 and use a separate declaration to specify the argument prototype:
|
|
|
429
|
|
|
430 @example
|
|
|
431 int foo (int, int);
|
|
|
432 @end example
|
|
|
433
|
|
|
434 You need such a declaration anyway, in a header file, to get the benefit
|
|
462
|
435 of prototypes in all the files where the function is called. And once
|
|
|
436 you have the declaration, you normally lose nothing by writing the
|
|
|
437 function definition in the pre-standard style.
|
|
428
|
438
|
|
|
439 This technique does not work for integer types narrower than @code{int}.
|
|
|
440 If you think of an argument as being of a type narrower than @code{int},
|
|
|
441 declare it as @code{int} instead.
|
|
|
442
|
|
|
443 There are a few special cases where this technique is hard to use. For
|
|
|
444 example, if a function argument needs to hold the system type
|
|
|
445 @code{dev_t}, you run into trouble, because @code{dev_t} is shorter than
|
|
|
446 @code{int} on some machines; but you cannot use @code{int} instead,
|
|
|
447 because @code{dev_t} is wider than @code{int} on some machines. There
|
|
462
|
448 is no type you can safely use on all machines in a non-standard
|
|
|
449 definition. The only way to support non-standard C and pass such an
|
|
428
|
450 argument is to check the width of @code{dev_t} using Autoconf and choose
|
|
|
451 the argument type accordingly. This may not be worth the trouble.
|
|
|
452
|
|
462
|
453 In order to support pre-standard compilers that do not recognize
|
|
|
454 prototypes, you may want to use a preprocessor macro like this:
|
|
|
455
|
|
|
456 @example
|
|
|
457 /* Declare the prototype for a general external function. */
|
|
|
458 #if defined (__STDC__) || defined (WINDOWSNT)
|
|
|
459 #define P_(proto) proto
|
|
|
460 #else
|
|
|
461 #define P_(proto) ()
|
|
|
462 #endif
|
|
|
463 @end example
|
|
428
|
464
|
|
|
465 @node Program Behavior
|
|
|
466 @chapter Program Behavior for All Programs
|
|
|
467
|
|
462
|
468 This @value{CHAPTER} describes conventions for writing robust
|
|
|
469 software. It also describes general standards for error messages, the
|
|
|
470 command line interface, and how libraries should behave.
|
|
428
|
471
|
|
|
472 @menu
|
|
|
473 * Semantics:: Writing robust programs
|
|
|
474 * Libraries:: Library behavior
|
|
|
475 * Errors:: Formatting error messages
|
|
462
|
476 * User Interfaces:: Standards about interfaces generally
|
|
|
477 * Graphical Interfaces:: Standards for graphical interfaces
|
|
|
478 * Command-Line Interfaces:: Standards for command line interfaces
|
|
|
479 * Option Table:: Table of long options
|
|
428
|
480 * Memory Usage:: When and how to care about memory needs
|
|
462
|
481 * File Usage:: Which files to use, and where
|
|
428
|
482 @end menu
|
|
|
483
|
|
|
484 @node Semantics
|
|
|
485 @section Writing Robust Programs
|
|
|
486
|
|
462
|
487 @cindex arbitrary limits on data
|
|
428
|
488 Avoid arbitrary limits on the length or number of @emph{any} data
|
|
|
489 structure, including file names, lines, files, and symbols, by allocating
|
|
|
490 all data structures dynamically. In most Unix utilities, ``long lines
|
|
|
491 are silently truncated''. This is not acceptable in a GNU utility.
|
|
|
492
|
|
462
|
493 @cindex @code{NUL} characters
|
|
428
|
494 Utilities reading files should not drop NUL characters, or any other
|
|
|
495 nonprinting characters @emph{including those with codes above 0177}.
|
|
|
496 The only sensible exceptions would be utilities specifically intended
|
|
|
497 for interface to certain types of terminals or printers
|
|
|
498 that can't handle those characters.
|
|
|
499 Whenever possible, try to make programs work properly with
|
|
|
500 sequences of bytes that represent multibyte characters, using encodings
|
|
|
501 such as UTF-8 and others.
|
|
|
502
|
|
462
|
503 @cindex error messages
|
|
428
|
504 Check every system call for an error return, unless you know you wish to
|
|
|
505 ignore errors. Include the system error text (from @code{perror} or
|
|
|
506 equivalent) in @emph{every} error message resulting from a failing
|
|
|
507 system call, as well as the name of the file if any and the name of the
|
|
|
508 utility. Just ``cannot open foo.c'' or ``stat failed'' is not
|
|
|
509 sufficient.
|
|
|
510
|
|
462
|
511 @cindex @code{malloc} return value
|
|
|
512 @cindex memory allocation failure
|
|
428
|
513 Check every call to @code{malloc} or @code{realloc} to see if it
|
|
|
514 returned zero. Check @code{realloc} even if you are making the block
|
|
|
515 smaller; in a system that rounds block sizes to a power of 2,
|
|
|
516 @code{realloc} may get a different block if you ask for less space.
|
|
|
517
|
|
|
518 In Unix, @code{realloc} can destroy the storage block if it returns
|
|
|
519 zero. GNU @code{realloc} does not have this bug: if it fails, the
|
|
|
520 original block is unchanged. Feel free to assume the bug is fixed. If
|
|
|
521 you wish to run your program on Unix, and wish to avoid lossage in this
|
|
|
522 case, you can use the GNU @code{malloc}.
|
|
|
523
|
|
|
524 You must expect @code{free} to alter the contents of the block that was
|
|
|
525 freed. Anything you want to fetch from the block, you must fetch before
|
|
|
526 calling @code{free}.
|
|
|
527
|
|
|
528 If @code{malloc} fails in a noninteractive program, make that a fatal
|
|
|
529 error. In an interactive program (one that reads commands from the
|
|
|
530 user), it is better to abort the command and return to the command
|
|
|
531 reader loop. This allows the user to kill other processes to free up
|
|
|
532 virtual memory, and then try the command again.
|
|
|
533
|
|
462
|
534 @cindex command-line arguments, decoding
|
|
428
|
535 Use @code{getopt_long} to decode arguments, unless the argument syntax
|
|
|
536 makes this unreasonable.
|
|
|
537
|
|
|
538 When static storage is to be written in during program execution, use
|
|
|
539 explicit C code to initialize it. Reserve C initialized declarations
|
|
|
540 for data that will not be changed.
|
|
|
541 @c ADR: why?
|
|
|
542
|
|
|
543 Try to avoid low-level interfaces to obscure Unix data structures (such
|
|
|
544 as file directories, utmp, or the layout of kernel memory), since these
|
|
|
545 are less likely to work compatibly. If you need to find all the files
|
|
|
546 in a directory, use @code{readdir} or some other high-level interface.
|
|
|
547 These are supported compatibly by GNU.
|
|
|
548
|
|
462
|
549 @cindex signal handling
|
|
428
|
550 The preferred signal handling facilities are the BSD variant of
|
|
|
551 @code{signal}, and the @sc{posix} @code{sigaction} function; the
|
|
|
552 alternative USG @code{signal} interface is an inferior design.
|
|
|
553
|
|
|
554 Nowadays, using the @sc{posix} signal functions may be the easiest way
|
|
|
555 to make a program portable. If you use @code{signal}, then on GNU/Linux
|
|
|
556 systems running GNU libc version 1, you should include
|
|
|
557 @file{bsd/signal.h} instead of @file{signal.h}, so as to get BSD
|
|
|
558 behavior. It is up to you whether to support systems where
|
|
|
559 @code{signal} has only the USG behavior, or give up on them.
|
|
|
560
|
|
462
|
561 @cindex impossible conditions
|
|
428
|
562 In error checks that detect ``impossible'' conditions, just abort.
|
|
|
563 There is usually no point in printing any message. These checks
|
|
|
564 indicate the existence of bugs. Whoever wants to fix the bugs will have
|
|
|
565 to read the source code and run a debugger. So explain the problem with
|
|
|
566 comments in the source. The relevant data will be in variables, which
|
|
|
567 are easy to examine with the debugger, so there is no point moving them
|
|
|
568 elsewhere.
|
|
|
569
|
|
|
570 Do not use a count of errors as the exit status for a program.
|
|
|
571 @emph{That does not work}, because exit status values are limited to 8
|
|
|
572 bits (0 through 255). A single run of the program might have 256
|
|
|
573 errors; if you try to return 256 as the exit status, the parent process
|
|
|
574 will see 0 as the status, and it will appear that the program succeeded.
|
|
|
575
|
|
462
|
576 @cindex temporary files
|
|
|
577 @cindex @code{TMPDIR} environment variable
|
|
428
|
578 If you make temporary files, check the @code{TMPDIR} environment
|
|
|
579 variable; if that variable is defined, use the specified directory
|
|
|
580 instead of @file{/tmp}.
|
|
|
581
|
|
462
|
582 In addition, be aware that there is a possible security problem when
|
|
|
583 creating temporary files in world-writable directories. In C, you can
|
|
|
584 avoid this problem by creating temporary files in this manner:
|
|
|
585
|
|
|
586 @example
|
|
|
587 fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0600);
|
|
|
588 @end example
|
|
|
589
|
|
|
590 @noindent
|
|
|
591 or by using the @code{mkstemps} function from libiberty.
|
|
|
592
|
|
|
593 In bash, use @code{set -C} to avoid this problem.
|
|
|
594
|
|
428
|
595 @node Libraries
|
|
|
596 @section Library Behavior
|
|
462
|
597 @cindex libraries
|
|
428
|
598
|
|
|
599 Try to make library functions reentrant. If they need to do dynamic
|
|
|
600 storage allocation, at least try to avoid any nonreentrancy aside from
|
|
|
601 that of @code{malloc} itself.
|
|
|
602
|
|
|
603 Here are certain name conventions for libraries, to avoid name
|
|
|
604 conflicts.
|
|
|
605
|
|
|
606 Choose a name prefix for the library, more than two characters long.
|
|
|
607 All external function and variable names should start with this
|
|
|
608 prefix. In addition, there should only be one of these in any given
|
|
|
609 library member. This usually means putting each one in a separate
|
|
|
610 source file.
|
|
|
611
|
|
|
612 An exception can be made when two external symbols are always used
|
|
|
613 together, so that no reasonable program could use one without the
|
|
|
614 other; then they can both go in the same file.
|
|
|
615
|
|
|
616 External symbols that are not documented entry points for the user
|
|
462
|
617 should have names beginning with @samp{_}. The @samp{_} should be
|
|
|
618 followed by the chosen name prefix for the library, to prevent
|
|
|
619 collisions with other libraries. These can go in the same files with
|
|
|
620 user entry points if you like.
|
|
428
|
621
|
|
|
622 Static functions and variables can be used as you like and need not
|
|
|
623 fit any naming convention.
|
|
|
624
|
|
|
625 @node Errors
|
|
|
626 @section Formatting Error Messages
|
|
462
|
627 @cindex formatting error messages
|
|
|
628 @cindex error messages, formatting
|
|
428
|
629
|
|
|
630 Error messages from compilers should look like this:
|
|
|
631
|
|
|
632 @example
|
|
|
633 @var{source-file-name}:@var{lineno}: @var{message}
|
|
|
634 @end example
|
|
|
635
|
|
|
636 @noindent
|
|
|
637 If you want to mention the column number, use this format:
|
|
|
638
|
|
|
639 @example
|
|
|
640 @var{source-file-name}:@var{lineno}:@var{column}: @var{message}
|
|
|
641 @end example
|
|
|
642
|
|
|
643 @noindent
|
|
|
644 Line numbers should start from 1 at the beginning of the file, and
|
|
|
645 column numbers should start from 1 at the beginning of the line. (Both
|
|
|
646 of these conventions are chosen for compatibility.) Calculate column
|
|
|
647 numbers assuming that space and all ASCII printing characters have
|
|
|
648 equal width, and assuming tab stops every 8 columns.
|
|
|
649
|
|
|
650 Error messages from other noninteractive programs should look like this:
|
|
|
651
|
|
|
652 @example
|
|
|
653 @var{program}:@var{source-file-name}:@var{lineno}: @var{message}
|
|
|
654 @end example
|
|
|
655
|
|
|
656 @noindent
|
|
|
657 when there is an appropriate source file, or like this:
|
|
|
658
|
|
|
659 @example
|
|
|
660 @var{program}: @var{message}
|
|
|
661 @end example
|
|
|
662
|
|
|
663 @noindent
|
|
|
664 when there is no relevant source file.
|
|
|
665
|
|
|
666 If you want to mention the column number, use this format:
|
|
|
667
|
|
|
668 @example
|
|
|
669 @var{program}:@var{source-file-name}:@var{lineno}:@var{column}: @var{message}
|
|
|
670 @end example
|
|
|
671
|
|
|
672 In an interactive program (one that is reading commands from a
|
|
|
673 terminal), it is better not to include the program name in an error
|
|
|
674 message. The place to indicate which program is running is in the
|
|
|
675 prompt or with the screen layout. (When the same program runs with
|
|
|
676 input from a source other than a terminal, it is not interactive and
|
|
|
677 would do best to print error messages using the noninteractive style.)
|
|
|
678
|
|
|
679 The string @var{message} should not begin with a capital letter when
|
|
|
680 it follows a program name and/or file name. Also, it should not end
|
|
|
681 with a period.
|
|
|
682
|
|
|
683 Error messages from interactive programs, and other messages such as
|
|
|
684 usage messages, should start with a capital letter. But they should not
|
|
|
685 end with a period.
|
|
|
686
|
|
|
687 @node User Interfaces
|
|
462
|
688 @section Standards for Interfaces Generally
|
|
|
689
|
|
|
690 @cindex program name and its behavior
|
|
|
691 @cindex behavior, dependent on program's name
|
|
428
|
692 Please don't make the behavior of a utility depend on the name used
|
|
|
693 to invoke it. It is useful sometimes to make a link to a utility
|
|
|
694 with a different name, and that should not change what it does.
|
|
|
695
|
|
|
696 Instead, use a run time option or a compilation switch or both
|
|
|
697 to select among the alternate behaviors.
|
|
|
698
|
|
462
|
699 @cindex output device and program's behavior
|
|
428
|
700 Likewise, please don't make the behavior of the program depend on the
|
|
|
701 type of output device it is used with. Device independence is an
|
|
|
702 important principle of the system's design; do not compromise it merely
|
|
|
703 to save someone from typing an option now and then. (Variation in error
|
|
|
704 message syntax when using a terminal is ok, because that is a side issue
|
|
|
705 that people do not depend on.)
|
|
|
706
|
|
|
707 If you think one behavior is most useful when the output is to a
|
|
|
708 terminal, and another is most useful when the output is a file or a
|
|
|
709 pipe, then it is usually best to make the default behavior the one that
|
|
|
710 is useful with output to a terminal, and have an option for the other
|
|
|
711 behavior.
|
|
|
712
|
|
|
713 Compatibility requires certain programs to depend on the type of output
|
|
|
714 device. It would be disastrous if @code{ls} or @code{sh} did not do so
|
|
|
715 in the way all users expect. In some of these cases, we supplement the
|
|
|
716 program with a preferred alternate version that does not depend on the
|
|
|
717 output device type. For example, we provide a @code{dir} program much
|
|
|
718 like @code{ls} except that its default output format is always
|
|
|
719 multi-column format.
|
|
|
720
|
|
462
|
721 @node Graphical Interfaces
|
|
|
722 @section Standards for Graphical Interfaces
|
|
|
723 @cindex graphical user interface
|
|
|
724
|
|
|
725 @cindex gtk
|
|
|
726 When you write a program that provides a graphical user interface,
|
|
|
727 please make it work with X Windows and the GTK toolkit unless the
|
|
|
728 functionality specifically requires some alternative (for example,
|
|
|
729 ``displaying jpeg images while in console mode'').
|
|
|
730
|
|
|
731 In addition, please provide a command-line interface to control the
|
|
|
732 functionality. (In many cases, the graphical user interface can be a
|
|
|
733 separate program which invokes the command-line program.) This is
|
|
|
734 so that the same jobs can be done from scripts.
|
|
|
735
|
|
|
736 @cindex corba
|
|
|
737 @cindex gnome
|
|
|
738 Please also consider providing a CORBA interface (for use from GNOME), a
|
|
|
739 library interface (for use from C), and perhaps a keyboard-driven
|
|
|
740 console interface (for use by users from console mode). Once you are
|
|
|
741 doing the work to provide the functionality and the graphical interface,
|
|
|
742 these won't be much extra work.
|
|
|
743
|
|
|
744 @node Command-Line Interfaces
|
|
|
745 @section Standards for Command Line Interfaces
|
|
|
746 @cindex command-line interface
|
|
|
747
|
|
|
748 @findex getopt
|
|
428
|
749 It is a good idea to follow the @sc{posix} guidelines for the
|
|
|
750 command-line options of a program. The easiest way to do this is to use
|
|
|
751 @code{getopt} to parse them. Note that the GNU version of @code{getopt}
|
|
|
752 will normally permit options anywhere among the arguments unless the
|
|
|
753 special argument @samp{--} is used. This is not what @sc{posix}
|
|
|
754 specifies; it is a GNU extension.
|
|
|
755
|
|
462
|
756 @cindex long-named options
|
|
428
|
757 Please define long-named options that are equivalent to the
|
|
|
758 single-letter Unix-style options. We hope to make GNU more user
|
|
|
759 friendly this way. This is easy to do with the GNU function
|
|
|
760 @code{getopt_long}.
|
|
|
761
|
|
|
762 One of the advantages of long-named options is that they can be
|
|
|
763 consistent from program to program. For example, users should be able
|
|
|
764 to expect the ``verbose'' option of any GNU program which has one, to be
|
|
|
765 spelled precisely @samp{--verbose}. To achieve this uniformity, look at
|
|
|
766 the table of common long-option names when you choose the option names
|
|
|
767 for your program (@pxref{Option Table}).
|
|
|
768
|
|
|
769 It is usually a good idea for file names given as ordinary arguments to
|
|
|
770 be input files only; any output files would be specified using options
|
|
|
771 (preferably @samp{-o} or @samp{--output}). Even if you allow an output
|
|
|
772 file name as an ordinary argument for compatibility, try to provide an
|
|
|
773 option as another way to specify it. This will lead to more consistency
|
|
|
774 among GNU utilities, and fewer idiosyncracies for users to remember.
|
|
|
775
|
|
462
|
776 @cindex standard command-line options
|
|
428
|
777 All programs should support two standard options: @samp{--version}
|
|
|
778 and @samp{--help}.
|
|
|
779
|
|
|
780 @table @code
|
|
462
|
781 @cindex @samp{--version} option
|
|
428
|
782 @item --version
|
|
|
783 This option should direct the program to print information about its name,
|
|
|
784 version, origin and legal status, all on standard output, and then exit
|
|
|
785 successfully. Other options and arguments should be ignored once this
|
|
|
786 is seen, and the program should not perform its normal function.
|
|
|
787
|
|
462
|
788 @cindex canonical name of a program
|
|
|
789 @cindex program's canonical name
|
|
428
|
790 The first line is meant to be easy for a program to parse; the version
|
|
|
791 number proper starts after the last space. In addition, it contains
|
|
|
792 the canonical name for this program, in this format:
|
|
|
793
|
|
|
794 @example
|
|
|
795 GNU Emacs 19.30
|
|
|
796 @end example
|
|
|
797
|
|
|
798 @noindent
|
|
|
799 The program's name should be a constant string; @emph{don't} compute it
|
|
|
800 from @code{argv[0]}. The idea is to state the standard or canonical
|
|
|
801 name for the program, not its file name. There are other ways to find
|
|
|
802 out the precise file name where a command is found in @code{PATH}.
|
|
|
803
|
|
|
804 If the program is a subsidiary part of a larger package, mention the
|
|
|
805 package name in parentheses, like this:
|
|
|
806
|
|
|
807 @example
|
|
|
808 emacsserver (GNU Emacs) 19.30
|
|
|
809 @end example
|
|
|
810
|
|
|
811 @noindent
|
|
|
812 If the package has a version number which is different from this
|
|
|
813 program's version number, you can mention the package version number
|
|
|
814 just before the close-parenthesis.
|
|
|
815
|
|
|
816 If you @strong{need} to mention the version numbers of libraries which
|
|
|
817 are distributed separately from the package which contains this program,
|
|
|
818 you can do so by printing an additional line of version info for each
|
|
|
819 library you want to mention. Use the same format for these lines as for
|
|
|
820 the first line.
|
|
|
821
|
|
|
822 Please do not mention all of the libraries that the program uses ``just
|
|
|
823 for completeness''---that would produce a lot of unhelpful clutter.
|
|
|
824 Please mention library version numbers only if you find in practice that
|
|
|
825 they are very important to you in debugging.
|
|
|
826
|
|
|
827 The following line, after the version number line or lines, should be a
|
|
|
828 copyright notice. If more than one copyright notice is called for, put
|
|
|
829 each on a separate line.
|
|
|
830
|
|
|
831 Next should follow a brief statement that the program is free software,
|
|
|
832 and that users are free to copy and change it on certain conditions. If
|
|
|
833 the program is covered by the GNU GPL, say so here. Also mention that
|
|
|
834 there is no warranty, to the extent permitted by law.
|
|
|
835
|
|
|
836 It is ok to finish the output with a list of the major authors of the
|
|
|
837 program, as a way of giving credit.
|
|
|
838
|
|
|
839 Here's an example of output that follows these rules:
|
|
|
840
|
|
|
841 @smallexample
|
|
|
842 GNU Emacs 19.34.5
|
|
|
843 Copyright (C) 1996 Free Software Foundation, Inc.
|
|
|
844 GNU Emacs comes with NO WARRANTY,
|
|
|
845 to the extent permitted by law.
|
|
|
846 You may redistribute copies of GNU Emacs
|
|
|
847 under the terms of the GNU General Public License.
|
|
|
848 For more information about these matters,
|
|
|
849 see the files named COPYING.
|
|
|
850 @end smallexample
|
|
|
851
|
|
|
852 You should adapt this to your program, of course, filling in the proper
|
|
|
853 year, copyright holder, name of program, and the references to
|
|
|
854 distribution terms, and changing the rest of the wording as necessary.
|
|
|
855
|
|
|
856 This copyright notice only needs to mention the most recent year in
|
|
|
857 which changes were made---there's no need to list the years for previous
|
|
|
858 versions' changes. You don't have to mention the name of the program in
|
|
|
859 these notices, if that is inconvenient, since it appeared in the first
|
|
|
860 line.
|
|
|
861
|
|
462
|
862 @cindex @samp{--help} option
|
|
428
|
863 @item --help
|
|
|
864 This option should output brief documentation for how to invoke the
|
|
|
865 program, on standard output, then exit successfully. Other options and
|
|
|
866 arguments should be ignored once this is seen, and the program should
|
|
|
867 not perform its normal function.
|
|
|
868
|
|
462
|
869 @cindex address for bug reports
|
|
|
870 @cindex bug reports
|
|
428
|
871 Near the end of the @samp{--help} option's output there should be a line
|
|
|
872 that says where to mail bug reports. It should have this format:
|
|
|
873
|
|
|
874 @example
|
|
|
875 Report bugs to @var{mailing-address}.
|
|
|
876 @end example
|
|
|
877 @end table
|
|
|
878
|
|
|
879 @node Option Table
|
|
|
880 @section Table of Long Options
|
|
462
|
881 @cindex long option names
|
|
|
882 @cindex table of long options
|
|
428
|
883
|
|
|
884 Here is a table of long options used by GNU programs. It is surely
|
|
|
885 incomplete, but we aim to list all the options that a new program might
|
|
|
886 want to be compatible with. If you use names not already in the table,
|
|
462
|
887 please send @email{bug-standards@@gnu.org} a list of them, with their
|
|
428
|
888 meanings, so we can update the table.
|
|
|
889
|
|
|
890 @c Please leave newlines between items in this table; it's much easier
|
|
|
891 @c to update when it isn't completely squashed together and unreadable.
|
|
|
892 @c When there is more than one short option for a long option name, put
|
|
|
893 @c a semicolon between the lists of the programs that use them, not a
|
|
|
894 @c period. --friedman
|
|
|
895
|
|
|
896 @table @samp
|
|
|
897 @item after-date
|
|
|
898 @samp{-N} in @code{tar}.
|
|
|
899
|
|
|
900 @item all
|
|
|
901 @samp{-a} in @code{du}, @code{ls}, @code{nm}, @code{stty}, @code{uname},
|
|
|
902 and @code{unexpand}.
|
|
|
903
|
|
|
904 @item all-text
|
|
|
905 @samp{-a} in @code{diff}.
|
|
|
906
|
|
|
907 @item almost-all
|
|
|
908 @samp{-A} in @code{ls}.
|
|
|
909
|
|
|
910 @item append
|
|
|
911 @samp{-a} in @code{etags}, @code{tee}, @code{time};
|
|
|
912 @samp{-r} in @code{tar}.
|
|
|
913
|
|
|
914 @item archive
|
|
|
915 @samp{-a} in @code{cp}.
|
|
|
916
|
|
|
917 @item archive-name
|
|
|
918 @samp{-n} in @code{shar}.
|
|
|
919
|
|
|
920 @item arglength
|
|
|
921 @samp{-l} in @code{m4}.
|
|
|
922
|
|
|
923 @item ascii
|
|
|
924 @samp{-a} in @code{diff}.
|
|
|
925
|
|
|
926 @item assign
|
|
|
927 @samp{-v} in @code{gawk}.
|
|
|
928
|
|
|
929 @item assume-new
|
|
|
930 @samp{-W} in Make.
|
|
|
931
|
|
|
932 @item assume-old
|
|
|
933 @samp{-o} in Make.
|
|
|
934
|
|
|
935 @item auto-check
|
|
|
936 @samp{-a} in @code{recode}.
|
|
|
937
|
|
|
938 @item auto-pager
|
|
|
939 @samp{-a} in @code{wdiff}.
|
|
|
940
|
|
|
941 @item auto-reference
|
|
|
942 @samp{-A} in @code{ptx}.
|
|
|
943
|
|
|
944 @item avoid-wraps
|
|
|
945 @samp{-n} in @code{wdiff}.
|
|
|
946
|
|
|
947 @item background
|
|
|
948 For server programs, run in the background.
|
|
|
949
|
|
|
950 @item backward-search
|
|
|
951 @samp{-B} in @code{ctags}.
|
|
|
952
|
|
|
953 @item basename
|
|
|
954 @samp{-f} in @code{shar}.
|
|
|
955
|
|
|
956 @item batch
|
|
|
957 Used in GDB.
|
|
|
958
|
|
|
959 @item baud
|
|
|
960 Used in GDB.
|
|
|
961
|
|
|
962 @item before
|
|
|
963 @samp{-b} in @code{tac}.
|
|
|
964
|
|
|
965 @item binary
|
|
|
966 @samp{-b} in @code{cpio} and @code{diff}.
|
|
|
967
|
|
|
968 @item bits-per-code
|
|
|
969 @samp{-b} in @code{shar}.
|
|
|
970
|
|
|
971 @item block-size
|
|
|
972 Used in @code{cpio} and @code{tar}.
|
|
|
973
|
|
|
974 @item blocks
|
|
|
975 @samp{-b} in @code{head} and @code{tail}.
|
|
|
976
|
|
|
977 @item break-file
|
|
|
978 @samp{-b} in @code{ptx}.
|
|
|
979
|
|
|
980 @item brief
|
|
|
981 Used in various programs to make output shorter.
|
|
|
982
|
|
|
983 @item bytes
|
|
|
984 @samp{-c} in @code{head}, @code{split}, and @code{tail}.
|
|
|
985
|
|
|
986 @item c@t{++}
|
|
|
987 @samp{-C} in @code{etags}.
|
|
|
988
|
|
|
989 @item catenate
|
|
|
990 @samp{-A} in @code{tar}.
|
|
|
991
|
|
|
992 @item cd
|
|
|
993 Used in various programs to specify the directory to use.
|
|
|
994
|
|
|
995 @item changes
|
|
|
996 @samp{-c} in @code{chgrp} and @code{chown}.
|
|
|
997
|
|
|
998 @item classify
|
|
|
999 @samp{-F} in @code{ls}.
|
|
|
1000
|
|
|
1001 @item colons
|
|
|
1002 @samp{-c} in @code{recode}.
|
|
|
1003
|
|
|
1004 @item command
|
|
|
1005 @samp{-c} in @code{su};
|
|
|
1006 @samp{-x} in GDB.
|
|
|
1007
|
|
|
1008 @item compare
|
|
|
1009 @samp{-d} in @code{tar}.
|
|
|
1010
|
|
|
1011 @item compat
|
|
|
1012 Used in @code{gawk}.
|
|
|
1013
|
|
|
1014 @item compress
|
|
|
1015 @samp{-Z} in @code{tar} and @code{shar}.
|
|
|
1016
|
|
|
1017 @item concatenate
|
|
|
1018 @samp{-A} in @code{tar}.
|
|
|
1019
|
|
|
1020 @item confirmation
|
|
|
1021 @samp{-w} in @code{tar}.
|
|
|
1022
|
|
|
1023 @item context
|
|
|
1024 Used in @code{diff}.
|
|
|
1025
|
|
|
1026 @item copyleft
|
|
|
1027 @samp{-W copyleft} in @code{gawk}.
|
|
|
1028
|
|
|
1029 @item copyright
|
|
|
1030 @samp{-C} in @code{ptx}, @code{recode}, and @code{wdiff};
|
|
|
1031 @samp{-W copyright} in @code{gawk}.
|
|
|
1032
|
|
|
1033 @item core
|
|
|
1034 Used in GDB.
|
|
|
1035
|
|
|
1036 @item count
|
|
|
1037 @samp{-q} in @code{who}.
|
|
|
1038
|
|
|
1039 @item count-links
|
|
|
1040 @samp{-l} in @code{du}.
|
|
|
1041
|
|
|
1042 @item create
|
|
|
1043 Used in @code{tar} and @code{cpio}.
|
|
|
1044
|
|
|
1045 @item cut-mark
|
|
|
1046 @samp{-c} in @code{shar}.
|
|
|
1047
|
|
|
1048 @item cxref
|
|
|
1049 @samp{-x} in @code{ctags}.
|
|
|
1050
|
|
|
1051 @item date
|
|
|
1052 @samp{-d} in @code{touch}.
|
|
|
1053
|
|
|
1054 @item debug
|
|
|
1055 @samp{-d} in Make and @code{m4};
|
|
|
1056 @samp{-t} in Bison.
|
|
|
1057
|
|
|
1058 @item define
|
|
|
1059 @samp{-D} in @code{m4}.
|
|
|
1060
|
|
|
1061 @item defines
|
|
|
1062 @samp{-d} in Bison and @code{ctags}.
|
|
|
1063
|
|
|
1064 @item delete
|
|
|
1065 @samp{-D} in @code{tar}.
|
|
|
1066
|
|
|
1067 @item dereference
|
|
|
1068 @samp{-L} in @code{chgrp}, @code{chown}, @code{cpio}, @code{du},
|
|
|
1069 @code{ls}, and @code{tar}.
|
|
|
1070
|
|
|
1071 @item dereference-args
|
|
|
1072 @samp{-D} in @code{du}.
|
|
|
1073
|
|
|
1074 @item device
|
|
|
1075 Specify an I/O device (special file name).
|
|
|
1076
|
|
|
1077 @item diacritics
|
|
|
1078 @samp{-d} in @code{recode}.
|
|
|
1079
|
|
|
1080 @item dictionary-order
|
|
|
1081 @samp{-d} in @code{look}.
|
|
|
1082
|
|
|
1083 @item diff
|
|
|
1084 @samp{-d} in @code{tar}.
|
|
|
1085
|
|
|
1086 @item digits
|
|
|
1087 @samp{-n} in @code{csplit}.
|
|
|
1088
|
|
|
1089 @item directory
|
|
|
1090 Specify the directory to use, in various programs. In @code{ls}, it
|
|
|
1091 means to show directories themselves rather than their contents. In
|
|
|
1092 @code{rm} and @code{ln}, it means to not treat links to directories
|
|
|
1093 specially.
|
|
|
1094
|
|
|
1095 @item discard-all
|
|
|
1096 @samp{-x} in @code{strip}.
|
|
|
1097
|
|
|
1098 @item discard-locals
|
|
|
1099 @samp{-X} in @code{strip}.
|
|
|
1100
|
|
|
1101 @item dry-run
|
|
|
1102 @samp{-n} in Make.
|
|
|
1103
|
|
|
1104 @item ed
|
|
|
1105 @samp{-e} in @code{diff}.
|
|
|
1106
|
|
|
1107 @item elide-empty-files
|
|
|
1108 @samp{-z} in @code{csplit}.
|
|
|
1109
|
|
|
1110 @item end-delete
|
|
|
1111 @samp{-x} in @code{wdiff}.
|
|
|
1112
|
|
|
1113 @item end-insert
|
|
|
1114 @samp{-z} in @code{wdiff}.
|
|
|
1115
|
|
|
1116 @item entire-new-file
|
|
|
1117 @samp{-N} in @code{diff}.
|
|
|
1118
|
|
|
1119 @item environment-overrides
|
|
|
1120 @samp{-e} in Make.
|
|
|
1121
|
|
|
1122 @item eof
|
|
|
1123 @samp{-e} in @code{xargs}.
|
|
|
1124
|
|
|
1125 @item epoch
|
|
|
1126 Used in GDB.
|
|
|
1127
|
|
|
1128 @item error-limit
|
|
|
1129 Used in @code{makeinfo}.
|
|
|
1130
|
|
|
1131 @item error-output
|
|
|
1132 @samp{-o} in @code{m4}.
|
|
|
1133
|
|
|
1134 @item escape
|
|
|
1135 @samp{-b} in @code{ls}.
|
|
|
1136
|
|
|
1137 @item exclude-from
|
|
|
1138 @samp{-X} in @code{tar}.
|
|
|
1139
|
|
|
1140 @item exec
|
|
|
1141 Used in GDB.
|
|
|
1142
|
|
|
1143 @item exit
|
|
|
1144 @samp{-x} in @code{xargs}.
|
|
|
1145
|
|
|
1146 @item exit-0
|
|
|
1147 @samp{-e} in @code{unshar}.
|
|
|
1148
|
|
|
1149 @item expand-tabs
|
|
|
1150 @samp{-t} in @code{diff}.
|
|
|
1151
|
|
|
1152 @item expression
|
|
|
1153 @samp{-e} in @code{sed}.
|
|
|
1154
|
|
|
1155 @item extern-only
|
|
|
1156 @samp{-g} in @code{nm}.
|
|
|
1157
|
|
|
1158 @item extract
|
|
|
1159 @samp{-i} in @code{cpio};
|
|
|
1160 @samp{-x} in @code{tar}.
|
|
|
1161
|
|
|
1162 @item faces
|
|
|
1163 @samp{-f} in @code{finger}.
|
|
|
1164
|
|
|
1165 @item fast
|
|
|
1166 @samp{-f} in @code{su}.
|
|
|
1167
|
|
|
1168 @item fatal-warnings
|
|
|
1169 @samp{-E} in @code{m4}.
|
|
|
1170
|
|
|
1171 @item file
|
|
|
1172 @samp{-f} in @code{info}, @code{gawk}, Make, @code{mt}, and @code{tar};
|
|
|
1173 @samp{-n} in @code{sed};
|
|
|
1174 @samp{-r} in @code{touch}.
|
|
|
1175
|
|
|
1176 @item field-separator
|
|
|
1177 @samp{-F} in @code{gawk}.
|
|
|
1178
|
|
|
1179 @item file-prefix
|
|
|
1180 @samp{-b} in Bison.
|
|
|
1181
|
|
|
1182 @item file-type
|
|
|
1183 @samp{-F} in @code{ls}.
|
|
|
1184
|
|
|
1185 @item files-from
|
|
|
1186 @samp{-T} in @code{tar}.
|
|
|
1187
|
|
|
1188 @item fill-column
|
|
|
1189 Used in @code{makeinfo}.
|
|
|
1190
|
|
|
1191 @item flag-truncation
|
|
|
1192 @samp{-F} in @code{ptx}.
|
|
|
1193
|
|
|
1194 @item fixed-output-files
|
|
|
1195 @samp{-y} in Bison.
|
|
|
1196
|
|
|
1197 @item follow
|
|
|
1198 @samp{-f} in @code{tail}.
|
|
|
1199
|
|
|
1200 @item footnote-style
|
|
|
1201 Used in @code{makeinfo}.
|
|
|
1202
|
|
|
1203 @item force
|
|
|
1204 @samp{-f} in @code{cp}, @code{ln}, @code{mv}, and @code{rm}.
|
|
|
1205
|
|
|
1206 @item force-prefix
|
|
|
1207 @samp{-F} in @code{shar}.
|
|
|
1208
|
|
|
1209 @item foreground
|
|
|
1210 For server programs, run in the foreground;
|
|
|
1211 in other words, don't do anything special to run the server
|
|
|
1212 in the background.
|
|
|
1213
|
|
|
1214 @item format
|
|
|
1215 Used in @code{ls}, @code{time}, and @code{ptx}.
|
|
|
1216
|
|
|
1217 @item freeze-state
|
|
|
1218 @samp{-F} in @code{m4}.
|
|
|
1219
|
|
|
1220 @item fullname
|
|
|
1221 Used in GDB.
|
|
|
1222
|
|
|
1223 @item gap-size
|
|
|
1224 @samp{-g} in @code{ptx}.
|
|
|
1225
|
|
|
1226 @item get
|
|
|
1227 @samp{-x} in @code{tar}.
|
|
|
1228
|
|
|
1229 @item graphic
|
|
|
1230 @samp{-i} in @code{ul}.
|
|
|
1231
|
|
|
1232 @item graphics
|
|
|
1233 @samp{-g} in @code{recode}.
|
|
|
1234
|
|
|
1235 @item group
|
|
|
1236 @samp{-g} in @code{install}.
|
|
|
1237
|
|
|
1238 @item gzip
|
|
|
1239 @samp{-z} in @code{tar} and @code{shar}.
|
|
|
1240
|
|
|
1241 @item hashsize
|
|
|
1242 @samp{-H} in @code{m4}.
|
|
|
1243
|
|
|
1244 @item header
|
|
|
1245 @samp{-h} in @code{objdump} and @code{recode}
|
|
|
1246
|
|
|
1247 @item heading
|
|
|
1248 @samp{-H} in @code{who}.
|
|
|
1249
|
|
|
1250 @item help
|
|
|
1251 Used to ask for brief usage information.
|
|
|
1252
|
|
|
1253 @item here-delimiter
|
|
|
1254 @samp{-d} in @code{shar}.
|
|
|
1255
|
|
|
1256 @item hide-control-chars
|
|
|
1257 @samp{-q} in @code{ls}.
|
|
|
1258
|
|
462
|
1259 @item html
|
|
|
1260 In @code{makeinfo}, output HTML.
|
|
|
1261
|
|
428
|
1262 @item idle
|
|
|
1263 @samp{-u} in @code{who}.
|
|
|
1264
|
|
|
1265 @item ifdef
|
|
|
1266 @samp{-D} in @code{diff}.
|
|
|
1267
|
|
|
1268 @item ignore
|
|
|
1269 @samp{-I} in @code{ls};
|
|
|
1270 @samp{-x} in @code{recode}.
|
|
|
1271
|
|
|
1272 @item ignore-all-space
|
|
|
1273 @samp{-w} in @code{diff}.
|
|
|
1274
|
|
|
1275 @item ignore-backups
|
|
|
1276 @samp{-B} in @code{ls}.
|
|
|
1277
|
|
|
1278 @item ignore-blank-lines
|
|
|
1279 @samp{-B} in @code{diff}.
|
|
|
1280
|
|
|
1281 @item ignore-case
|
|
|
1282 @samp{-f} in @code{look} and @code{ptx};
|
|
|
1283 @samp{-i} in @code{diff} and @code{wdiff}.
|
|
|
1284
|
|
|
1285 @item ignore-errors
|
|
|
1286 @samp{-i} in Make.
|
|
|
1287
|
|
|
1288 @item ignore-file
|
|
|
1289 @samp{-i} in @code{ptx}.
|
|
|
1290
|
|
|
1291 @item ignore-indentation
|
|
|
1292 @samp{-I} in @code{etags}.
|
|
|
1293
|
|
|
1294 @item ignore-init-file
|
|
|
1295 @samp{-f} in Oleo.
|
|
|
1296
|
|
|
1297 @item ignore-interrupts
|
|
|
1298 @samp{-i} in @code{tee}.
|
|
|
1299
|
|
|
1300 @item ignore-matching-lines
|
|
|
1301 @samp{-I} in @code{diff}.
|
|
|
1302
|
|
|
1303 @item ignore-space-change
|
|
|
1304 @samp{-b} in @code{diff}.
|
|
|
1305
|
|
|
1306 @item ignore-zeros
|
|
|
1307 @samp{-i} in @code{tar}.
|
|
|
1308
|
|
|
1309 @item include
|
|
|
1310 @samp{-i} in @code{etags};
|
|
|
1311 @samp{-I} in @code{m4}.
|
|
|
1312
|
|
|
1313 @item include-dir
|
|
|
1314 @samp{-I} in Make.
|
|
|
1315
|
|
|
1316 @item incremental
|
|
|
1317 @samp{-G} in @code{tar}.
|
|
|
1318
|
|
|
1319 @item info
|
|
|
1320 @samp{-i}, @samp{-l}, and @samp{-m} in Finger.
|
|
|
1321
|
|
462
|
1322 @item init-file
|
|
|
1323 In some programs, specify the name of the file to read as the user's
|
|
|
1324 init file.
|
|
|
1325
|
|
428
|
1326 @item initial
|
|
|
1327 @samp{-i} in @code{expand}.
|
|
|
1328
|
|
|
1329 @item initial-tab
|
|
|
1330 @samp{-T} in @code{diff}.
|
|
|
1331
|
|
|
1332 @item inode
|
|
|
1333 @samp{-i} in @code{ls}.
|
|
|
1334
|
|
|
1335 @item interactive
|
|
|
1336 @samp{-i} in @code{cp}, @code{ln}, @code{mv}, @code{rm};
|
|
|
1337 @samp{-e} in @code{m4};
|
|
|
1338 @samp{-p} in @code{xargs};
|
|
|
1339 @samp{-w} in @code{tar}.
|
|
|
1340
|
|
|
1341 @item intermix-type
|
|
|
1342 @samp{-p} in @code{shar}.
|
|
|
1343
|
|
462
|
1344 @item iso-8601
|
|
|
1345 Used in @code{date}
|
|
|
1346
|
|
428
|
1347 @item jobs
|
|
|
1348 @samp{-j} in Make.
|
|
|
1349
|
|
|
1350 @item just-print
|
|
|
1351 @samp{-n} in Make.
|
|
|
1352
|
|
|
1353 @item keep-going
|
|
|
1354 @samp{-k} in Make.
|
|
|
1355
|
|
|
1356 @item keep-files
|
|
|
1357 @samp{-k} in @code{csplit}.
|
|
|
1358
|
|
|
1359 @item kilobytes
|
|
|
1360 @samp{-k} in @code{du} and @code{ls}.
|
|
|
1361
|
|
|
1362 @item language
|
|
|
1363 @samp{-l} in @code{etags}.
|
|
|
1364
|
|
|
1365 @item less-mode
|
|
|
1366 @samp{-l} in @code{wdiff}.
|
|
|
1367
|
|
|
1368 @item level-for-gzip
|
|
|
1369 @samp{-g} in @code{shar}.
|
|
|
1370
|
|
|
1371 @item line-bytes
|
|
|
1372 @samp{-C} in @code{split}.
|
|
|
1373
|
|
|
1374 @item lines
|
|
|
1375 Used in @code{split}, @code{head}, and @code{tail}.
|
|
|
1376
|
|
|
1377 @item link
|
|
|
1378 @samp{-l} in @code{cpio}.
|
|
|
1379
|
|
|
1380 @item lint
|
|
|
1381 @itemx lint-old
|
|
|
1382 Used in @code{gawk}.
|
|
|
1383
|
|
|
1384 @item list
|
|
|
1385 @samp{-t} in @code{cpio};
|
|
|
1386 @samp{-l} in @code{recode}.
|
|
|
1387
|
|
|
1388 @item list
|
|
|
1389 @samp{-t} in @code{tar}.
|
|
|
1390
|
|
|
1391 @item literal
|
|
|
1392 @samp{-N} in @code{ls}.
|
|
|
1393
|
|
|
1394 @item load-average
|
|
|
1395 @samp{-l} in Make.
|
|
|
1396
|
|
|
1397 @item login
|
|
|
1398 Used in @code{su}.
|
|
|
1399
|
|
|
1400 @item machine
|
|
|
1401 No listing of which programs already use this;
|
|
|
1402 someone should check to
|
|
|
1403 see if any actually do, and tell @email{gnu@@gnu.org}.
|
|
|
1404
|
|
|
1405 @item macro-name
|
|
|
1406 @samp{-M} in @code{ptx}.
|
|
|
1407
|
|
|
1408 @item mail
|
|
|
1409 @samp{-m} in @code{hello} and @code{uname}.
|
|
|
1410
|
|
|
1411 @item make-directories
|
|
|
1412 @samp{-d} in @code{cpio}.
|
|
|
1413
|
|
|
1414 @item makefile
|
|
|
1415 @samp{-f} in Make.
|
|
|
1416
|
|
|
1417 @item mapped
|
|
|
1418 Used in GDB.
|
|
|
1419
|
|
|
1420 @item max-args
|
|
|
1421 @samp{-n} in @code{xargs}.
|
|
|
1422
|
|
|
1423 @item max-chars
|
|
|
1424 @samp{-n} in @code{xargs}.
|
|
|
1425
|
|
|
1426 @item max-lines
|
|
|
1427 @samp{-l} in @code{xargs}.
|
|
|
1428
|
|
|
1429 @item max-load
|
|
|
1430 @samp{-l} in Make.
|
|
|
1431
|
|
|
1432 @item max-procs
|
|
|
1433 @samp{-P} in @code{xargs}.
|
|
|
1434
|
|
|
1435 @item mesg
|
|
|
1436 @samp{-T} in @code{who}.
|
|
|
1437
|
|
|
1438 @item message
|
|
|
1439 @samp{-T} in @code{who}.
|
|
|
1440
|
|
|
1441 @item minimal
|
|
|
1442 @samp{-d} in @code{diff}.
|
|
|
1443
|
|
|
1444 @item mixed-uuencode
|
|
|
1445 @samp{-M} in @code{shar}.
|
|
|
1446
|
|
|
1447 @item mode
|
|
|
1448 @samp{-m} in @code{install}, @code{mkdir}, and @code{mkfifo}.
|
|
|
1449
|
|
|
1450 @item modification-time
|
|
|
1451 @samp{-m} in @code{tar}.
|
|
|
1452
|
|
|
1453 @item multi-volume
|
|
|
1454 @samp{-M} in @code{tar}.
|
|
|
1455
|
|
|
1456 @item name-prefix
|
|
|
1457 @samp{-a} in Bison.
|
|
|
1458
|
|
|
1459 @item nesting-limit
|
|
|
1460 @samp{-L} in @code{m4}.
|
|
|
1461
|
|
|
1462 @item net-headers
|
|
|
1463 @samp{-a} in @code{shar}.
|
|
|
1464
|
|
|
1465 @item new-file
|
|
|
1466 @samp{-W} in Make.
|
|
|
1467
|
|
|
1468 @item no-builtin-rules
|
|
|
1469 @samp{-r} in Make.
|
|
|
1470
|
|
|
1471 @item no-character-count
|
|
|
1472 @samp{-w} in @code{shar}.
|
|
|
1473
|
|
|
1474 @item no-check-existing
|
|
|
1475 @samp{-x} in @code{shar}.
|
|
|
1476
|
|
|
1477 @item no-common
|
|
|
1478 @samp{-3} in @code{wdiff}.
|
|
|
1479
|
|
|
1480 @item no-create
|
|
|
1481 @samp{-c} in @code{touch}.
|
|
|
1482
|
|
|
1483 @item no-defines
|
|
|
1484 @samp{-D} in @code{etags}.
|
|
|
1485
|
|
|
1486 @item no-deleted
|
|
|
1487 @samp{-1} in @code{wdiff}.
|
|
|
1488
|
|
|
1489 @item no-dereference
|
|
|
1490 @samp{-d} in @code{cp}.
|
|
|
1491
|
|
|
1492 @item no-inserted
|
|
|
1493 @samp{-2} in @code{wdiff}.
|
|
|
1494
|
|
|
1495 @item no-keep-going
|
|
|
1496 @samp{-S} in Make.
|
|
|
1497
|
|
|
1498 @item no-lines
|
|
|
1499 @samp{-l} in Bison.
|
|
|
1500
|
|
|
1501 @item no-piping
|
|
|
1502 @samp{-P} in @code{shar}.
|
|
|
1503
|
|
|
1504 @item no-prof
|
|
|
1505 @samp{-e} in @code{gprof}.
|
|
|
1506
|
|
|
1507 @item no-regex
|
|
|
1508 @samp{-R} in @code{etags}.
|
|
|
1509
|
|
|
1510 @item no-sort
|
|
|
1511 @samp{-p} in @code{nm}.
|
|
|
1512
|
|
|
1513 @item no-split
|
|
|
1514 Used in @code{makeinfo}.
|
|
|
1515
|
|
|
1516 @item no-static
|
|
|
1517 @samp{-a} in @code{gprof}.
|
|
|
1518
|
|
|
1519 @item no-time
|
|
|
1520 @samp{-E} in @code{gprof}.
|
|
|
1521
|
|
|
1522 @item no-timestamp
|
|
|
1523 @samp{-m} in @code{shar}.
|
|
|
1524
|
|
|
1525 @item no-validate
|
|
|
1526 Used in @code{makeinfo}.
|
|
|
1527
|
|
|
1528 @item no-wait
|
|
|
1529 Used in @code{emacsclient}.
|
|
|
1530
|
|
|
1531 @item no-warn
|
|
|
1532 Used in various programs to inhibit warnings.
|
|
|
1533
|
|
|
1534 @item node
|
|
|
1535 @samp{-n} in @code{info}.
|
|
|
1536
|
|
|
1537 @item nodename
|
|
|
1538 @samp{-n} in @code{uname}.
|
|
|
1539
|
|
|
1540 @item nonmatching
|
|
|
1541 @samp{-f} in @code{cpio}.
|
|
|
1542
|
|
|
1543 @item nstuff
|
|
|
1544 @samp{-n} in @code{objdump}.
|
|
|
1545
|
|
|
1546 @item null
|
|
|
1547 @samp{-0} in @code{xargs}.
|
|
|
1548
|
|
|
1549 @item number
|
|
|
1550 @samp{-n} in @code{cat}.
|
|
|
1551
|
|
|
1552 @item number-nonblank
|
|
|
1553 @samp{-b} in @code{cat}.
|
|
|
1554
|
|
|
1555 @item numeric-sort
|
|
|
1556 @samp{-n} in @code{nm}.
|
|
|
1557
|
|
|
1558 @item numeric-uid-gid
|
|
|
1559 @samp{-n} in @code{cpio} and @code{ls}.
|
|
|
1560
|
|
|
1561 @item nx
|
|
|
1562 Used in GDB.
|
|
|
1563
|
|
|
1564 @item old-archive
|
|
|
1565 @samp{-o} in @code{tar}.
|
|
|
1566
|
|
|
1567 @item old-file
|
|
|
1568 @samp{-o} in Make.
|
|
|
1569
|
|
|
1570 @item one-file-system
|
|
|
1571 @samp{-l} in @code{tar}, @code{cp}, and @code{du}.
|
|
|
1572
|
|
|
1573 @item only-file
|
|
|
1574 @samp{-o} in @code{ptx}.
|
|
|
1575
|
|
|
1576 @item only-prof
|
|
|
1577 @samp{-f} in @code{gprof}.
|
|
|
1578
|
|
|
1579 @item only-time
|
|
|
1580 @samp{-F} in @code{gprof}.
|
|
|
1581
|
|
|
1582 @item options
|
|
|
1583 @samp{-o} in @code{getopt}, @code{fdlist}, @code{fdmount},
|
|
|
1584 @code{fdmountd}, and @code{fdumount}.
|
|
|
1585
|
|
|
1586 @item output
|
|
|
1587 In various programs, specify the output file name.
|
|
|
1588
|
|
|
1589 @item output-prefix
|
|
|
1590 @samp{-o} in @code{shar}.
|
|
|
1591
|
|
|
1592 @item override
|
|
|
1593 @samp{-o} in @code{rm}.
|
|
|
1594
|
|
|
1595 @item overwrite
|
|
|
1596 @samp{-c} in @code{unshar}.
|
|
|
1597
|
|
|
1598 @item owner
|
|
|
1599 @samp{-o} in @code{install}.
|
|
|
1600
|
|
|
1601 @item paginate
|
|
|
1602 @samp{-l} in @code{diff}.
|
|
|
1603
|
|
|
1604 @item paragraph-indent
|
|
|
1605 Used in @code{makeinfo}.
|
|
|
1606
|
|
|
1607 @item parents
|
|
|
1608 @samp{-p} in @code{mkdir} and @code{rmdir}.
|
|
|
1609
|
|
|
1610 @item pass-all
|
|
|
1611 @samp{-p} in @code{ul}.
|
|
|
1612
|
|
|
1613 @item pass-through
|
|
|
1614 @samp{-p} in @code{cpio}.
|
|
|
1615
|
|
|
1616 @item port
|
|
|
1617 @samp{-P} in @code{finger}.
|
|
|
1618
|
|
|
1619 @item portability
|
|
|
1620 @samp{-c} in @code{cpio} and @code{tar}.
|
|
|
1621
|
|
|
1622 @item posix
|
|
|
1623 Used in @code{gawk}.
|
|
|
1624
|
|
|
1625 @item prefix-builtins
|
|
|
1626 @samp{-P} in @code{m4}.
|
|
|
1627
|
|
|
1628 @item prefix
|
|
|
1629 @samp{-f} in @code{csplit}.
|
|
|
1630
|
|
|
1631 @item preserve
|
|
|
1632 Used in @code{tar} and @code{cp}.
|
|
|
1633
|
|
|
1634 @item preserve-environment
|
|
|
1635 @samp{-p} in @code{su}.
|
|
|
1636
|
|
|
1637 @item preserve-modification-time
|
|
|
1638 @samp{-m} in @code{cpio}.
|
|
|
1639
|
|
|
1640 @item preserve-order
|
|
|
1641 @samp{-s} in @code{tar}.
|
|
|
1642
|
|
|
1643 @item preserve-permissions
|
|
|
1644 @samp{-p} in @code{tar}.
|
|
|
1645
|
|
|
1646 @item print
|
|
|
1647 @samp{-l} in @code{diff}.
|
|
|
1648
|
|
|
1649 @item print-chars
|
|
|
1650 @samp{-L} in @code{cmp}.
|
|
|
1651
|
|
|
1652 @item print-data-base
|
|
|
1653 @samp{-p} in Make.
|
|
|
1654
|
|
|
1655 @item print-directory
|
|
|
1656 @samp{-w} in Make.
|
|
|
1657
|
|
|
1658 @item print-file-name
|
|
|
1659 @samp{-o} in @code{nm}.
|
|
|
1660
|
|
|
1661 @item print-symdefs
|
|
|
1662 @samp{-s} in @code{nm}.
|
|
|
1663
|
|
|
1664 @item printer
|
|
|
1665 @samp{-p} in @code{wdiff}.
|
|
|
1666
|
|
|
1667 @item prompt
|
|
|
1668 @samp{-p} in @code{ed}.
|
|
|
1669
|
|
|
1670 @item proxy
|
|
|
1671 Specify an HTTP proxy.
|
|
|
1672
|
|
|
1673 @item query-user
|
|
|
1674 @samp{-X} in @code{shar}.
|
|
|
1675
|
|
|
1676 @item question
|
|
|
1677 @samp{-q} in Make.
|
|
|
1678
|
|
|
1679 @item quiet
|
|
2665
|
1680 Used in many programs to inhibit the usual output. @strong{Every
|
|
|
1681 program accepting @samp{--quiet}} should accept @samp{--silent} as a
|
|
428
|
1682 synonym.
|
|
|
1683
|
|
|
1684 @item quiet-unshar
|
|
|
1685 @samp{-Q} in @code{shar}
|
|
|
1686
|
|
|
1687 @item quote-name
|
|
|
1688 @samp{-Q} in @code{ls}.
|
|
|
1689
|
|
|
1690 @item rcs
|
|
|
1691 @samp{-n} in @code{diff}.
|
|
|
1692
|
|
|
1693 @item re-interval
|
|
|
1694 Used in @code{gawk}.
|
|
|
1695
|
|
|
1696 @item read-full-blocks
|
|
|
1697 @samp{-B} in @code{tar}.
|
|
|
1698
|
|
|
1699 @item readnow
|
|
|
1700 Used in GDB.
|
|
|
1701
|
|
|
1702 @item recon
|
|
|
1703 @samp{-n} in Make.
|
|
|
1704
|
|
|
1705 @item record-number
|
|
|
1706 @samp{-R} in @code{tar}.
|
|
|
1707
|
|
|
1708 @item recursive
|
|
|
1709 Used in @code{chgrp}, @code{chown}, @code{cp}, @code{ls}, @code{diff},
|
|
|
1710 and @code{rm}.
|
|
|
1711
|
|
|
1712 @item reference-limit
|
|
|
1713 Used in @code{makeinfo}.
|
|
|
1714
|
|
|
1715 @item references
|
|
|
1716 @samp{-r} in @code{ptx}.
|
|
|
1717
|
|
|
1718 @item regex
|
|
|
1719 @samp{-r} in @code{tac} and @code{etags}.
|
|
|
1720
|
|
|
1721 @item release
|
|
|
1722 @samp{-r} in @code{uname}.
|
|
|
1723
|
|
|
1724 @item reload-state
|
|
|
1725 @samp{-R} in @code{m4}.
|
|
|
1726
|
|
|
1727 @item relocation
|
|
|
1728 @samp{-r} in @code{objdump}.
|
|
|
1729
|
|
|
1730 @item rename
|
|
|
1731 @samp{-r} in @code{cpio}.
|
|
|
1732
|
|
|
1733 @item replace
|
|
|
1734 @samp{-i} in @code{xargs}.
|
|
|
1735
|
|
|
1736 @item report-identical-files
|
|
|
1737 @samp{-s} in @code{diff}.
|
|
|
1738
|
|
|
1739 @item reset-access-time
|
|
|
1740 @samp{-a} in @code{cpio}.
|
|
|
1741
|
|
|
1742 @item reverse
|
|
|
1743 @samp{-r} in @code{ls} and @code{nm}.
|
|
|
1744
|
|
|
1745 @item reversed-ed
|
|
|
1746 @samp{-f} in @code{diff}.
|
|
|
1747
|
|
|
1748 @item right-side-defs
|
|
|
1749 @samp{-R} in @code{ptx}.
|
|
|
1750
|
|
|
1751 @item same-order
|
|
|
1752 @samp{-s} in @code{tar}.
|
|
|
1753
|
|
|
1754 @item same-permissions
|
|
|
1755 @samp{-p} in @code{tar}.
|
|
|
1756
|
|
|
1757 @item save
|
|
|
1758 @samp{-g} in @code{stty}.
|
|
|
1759
|
|
|
1760 @item se
|
|
|
1761 Used in GDB.
|
|
|
1762
|
|
|
1763 @item sentence-regexp
|
|
|
1764 @samp{-S} in @code{ptx}.
|
|
|
1765
|
|
|
1766 @item separate-dirs
|
|
|
1767 @samp{-S} in @code{du}.
|
|
|
1768
|
|
|
1769 @item separator
|
|
|
1770 @samp{-s} in @code{tac}.
|
|
|
1771
|
|
|
1772 @item sequence
|
|
|
1773 Used by @code{recode} to chose files or pipes for sequencing passes.
|
|
|
1774
|
|
|
1775 @item shell
|
|
|
1776 @samp{-s} in @code{su}.
|
|
|
1777
|
|
|
1778 @item show-all
|
|
|
1779 @samp{-A} in @code{cat}.
|
|
|
1780
|
|
|
1781 @item show-c-function
|
|
|
1782 @samp{-p} in @code{diff}.
|
|
|
1783
|
|
|
1784 @item show-ends
|
|
|
1785 @samp{-E} in @code{cat}.
|
|
|
1786
|
|
|
1787 @item show-function-line
|
|
|
1788 @samp{-F} in @code{diff}.
|
|
|
1789
|
|
|
1790 @item show-tabs
|
|
|
1791 @samp{-T} in @code{cat}.
|
|
|
1792
|
|
|
1793 @item silent
|
|
|
1794 Used in many programs to inhibit the usual output.
|
|
2665
|
1795 @strong{Every program accepting
|
|
|
1796 @samp{--silent}} should accept @samp{--quiet} as a synonym.
|
|
428
|
1797
|
|
|
1798 @item size
|
|
|
1799 @samp{-s} in @code{ls}.
|
|
|
1800
|
|
|
1801 @item socket
|
|
|
1802 Specify a file descriptor for a network server to use for its socket,
|
|
|
1803 instead of opening and binding a new socket. This provides a way to
|
|
|
1804 run, in a nonpriveledged process, a server that normally needs a
|
|
|
1805 reserved port number.
|
|
|
1806
|
|
|
1807 @item sort
|
|
|
1808 Used in @code{ls}.
|
|
|
1809
|
|
|
1810 @item source
|
|
|
1811 @samp{-W source} in @code{gawk}.
|
|
|
1812
|
|
|
1813 @item sparse
|
|
|
1814 @samp{-S} in @code{tar}.
|
|
|
1815
|
|
|
1816 @item speed-large-files
|
|
|
1817 @samp{-H} in @code{diff}.
|
|
|
1818
|
|
|
1819 @item split-at
|
|
|
1820 @samp{-E} in @code{unshar}.
|
|
|
1821
|
|
|
1822 @item split-size-limit
|
|
|
1823 @samp{-L} in @code{shar}.
|
|
|
1824
|
|
|
1825 @item squeeze-blank
|
|
|
1826 @samp{-s} in @code{cat}.
|
|
|
1827
|
|
|
1828 @item start-delete
|
|
|
1829 @samp{-w} in @code{wdiff}.
|
|
|
1830
|
|
|
1831 @item start-insert
|
|
|
1832 @samp{-y} in @code{wdiff}.
|
|
|
1833
|
|
|
1834 @item starting-file
|
|
|
1835 Used in @code{tar} and @code{diff} to specify which file within
|
|
|
1836 a directory to start processing with.
|
|
|
1837
|
|
|
1838 @item statistics
|
|
|
1839 @samp{-s} in @code{wdiff}.
|
|
|
1840
|
|
|
1841 @item stdin-file-list
|
|
|
1842 @samp{-S} in @code{shar}.
|
|
|
1843
|
|
|
1844 @item stop
|
|
|
1845 @samp{-S} in Make.
|
|
|
1846
|
|
|
1847 @item strict
|
|
|
1848 @samp{-s} in @code{recode}.
|
|
|
1849
|
|
|
1850 @item strip
|
|
|
1851 @samp{-s} in @code{install}.
|
|
|
1852
|
|
|
1853 @item strip-all
|
|
|
1854 @samp{-s} in @code{strip}.
|
|
|
1855
|
|
|
1856 @item strip-debug
|
|
|
1857 @samp{-S} in @code{strip}.
|
|
|
1858
|
|
|
1859 @item submitter
|
|
|
1860 @samp{-s} in @code{shar}.
|
|
|
1861
|
|
|
1862 @item suffix
|
|
|
1863 @samp{-S} in @code{cp}, @code{ln}, @code{mv}.
|
|
|
1864
|
|
|
1865 @item suffix-format
|
|
|
1866 @samp{-b} in @code{csplit}.
|
|
|
1867
|
|
|
1868 @item sum
|
|
|
1869 @samp{-s} in @code{gprof}.
|
|
|
1870
|
|
|
1871 @item summarize
|
|
|
1872 @samp{-s} in @code{du}.
|
|
|
1873
|
|
|
1874 @item symbolic
|
|
|
1875 @samp{-s} in @code{ln}.
|
|
|
1876
|
|
|
1877 @item symbols
|
|
|
1878 Used in GDB and @code{objdump}.
|
|
|
1879
|
|
|
1880 @item synclines
|
|
|
1881 @samp{-s} in @code{m4}.
|
|
|
1882
|
|
|
1883 @item sysname
|
|
|
1884 @samp{-s} in @code{uname}.
|
|
|
1885
|
|
|
1886 @item tabs
|
|
|
1887 @samp{-t} in @code{expand} and @code{unexpand}.
|
|
|
1888
|
|
|
1889 @item tabsize
|
|
|
1890 @samp{-T} in @code{ls}.
|
|
|
1891
|
|
|
1892 @item terminal
|
|
|
1893 @samp{-T} in @code{tput} and @code{ul}.
|
|
|
1894 @samp{-t} in @code{wdiff}.
|
|
|
1895
|
|
|
1896 @item text
|
|
|
1897 @samp{-a} in @code{diff}.
|
|
|
1898
|
|
|
1899 @item text-files
|
|
|
1900 @samp{-T} in @code{shar}.
|
|
|
1901
|
|
|
1902 @item time
|
|
|
1903 Used in @code{ls} and @code{touch}.
|
|
|
1904
|
|
|
1905 @item timeout
|
|
|
1906 Specify how long to wait before giving up on some operation.
|
|
|
1907
|
|
|
1908 @item to-stdout
|
|
|
1909 @samp{-O} in @code{tar}.
|
|
|
1910
|
|
|
1911 @item total
|
|
|
1912 @samp{-c} in @code{du}.
|
|
|
1913
|
|
|
1914 @item touch
|
|
|
1915 @samp{-t} in Make, @code{ranlib}, and @code{recode}.
|
|
|
1916
|
|
|
1917 @item trace
|
|
|
1918 @samp{-t} in @code{m4}.
|
|
|
1919
|
|
|
1920 @item traditional
|
|
|
1921 @samp{-t} in @code{hello};
|
|
|
1922 @samp{-W traditional} in @code{gawk};
|
|
|
1923 @samp{-G} in @code{ed}, @code{m4}, and @code{ptx}.
|
|
|
1924
|
|
|
1925 @item tty
|
|
|
1926 Used in GDB.
|
|
|
1927
|
|
|
1928 @item typedefs
|
|
|
1929 @samp{-t} in @code{ctags}.
|
|
|
1930
|
|
|
1931 @item typedefs-and-c++
|
|
|
1932 @samp{-T} in @code{ctags}.
|
|
|
1933
|
|
|
1934 @item typeset-mode
|
|
|
1935 @samp{-t} in @code{ptx}.
|
|
|
1936
|
|
|
1937 @item uncompress
|
|
|
1938 @samp{-z} in @code{tar}.
|
|
|
1939
|
|
|
1940 @item unconditional
|
|
|
1941 @samp{-u} in @code{cpio}.
|
|
|
1942
|
|
|
1943 @item undefine
|
|
|
1944 @samp{-U} in @code{m4}.
|
|
|
1945
|
|
|
1946 @item undefined-only
|
|
|
1947 @samp{-u} in @code{nm}.
|
|
|
1948
|
|
|
1949 @item update
|
|
|
1950 @samp{-u} in @code{cp}, @code{ctags}, @code{mv}, @code{tar}.
|
|
|
1951
|
|
|
1952 @item usage
|
|
|
1953 Used in @code{gawk}; same as @samp{--help}.
|
|
|
1954
|
|
|
1955 @item uuencode
|
|
|
1956 @samp{-B} in @code{shar}.
|
|
|
1957
|
|
|
1958 @item vanilla-operation
|
|
|
1959 @samp{-V} in @code{shar}.
|
|
|
1960
|
|
|
1961 @item verbose
|
|
|
1962 Print more information about progress. Many programs support this.
|
|
|
1963
|
|
|
1964 @item verify
|
|
|
1965 @samp{-W} in @code{tar}.
|
|
|
1966
|
|
|
1967 @item version
|
|
|
1968 Print the version number.
|
|
|
1969
|
|
|
1970 @item version-control
|
|
|
1971 @samp{-V} in @code{cp}, @code{ln}, @code{mv}.
|
|
|
1972
|
|
|
1973 @item vgrind
|
|
|
1974 @samp{-v} in @code{ctags}.
|
|
|
1975
|
|
|
1976 @item volume
|
|
|
1977 @samp{-V} in @code{tar}.
|
|
|
1978
|
|
|
1979 @item what-if
|
|
|
1980 @samp{-W} in Make.
|
|
|
1981
|
|
|
1982 @item whole-size-limit
|
|
|
1983 @samp{-l} in @code{shar}.
|
|
|
1984
|
|
|
1985 @item width
|
|
|
1986 @samp{-w} in @code{ls} and @code{ptx}.
|
|
|
1987
|
|
|
1988 @item word-regexp
|
|
|
1989 @samp{-W} in @code{ptx}.
|
|
|
1990
|
|
|
1991 @item writable
|
|
|
1992 @samp{-T} in @code{who}.
|
|
|
1993
|
|
|
1994 @item zeros
|
|
|
1995 @samp{-z} in @code{gprof}.
|
|
|
1996 @end table
|
|
|
1997
|
|
|
1998 @node Memory Usage
|
|
|
1999 @section Memory Usage
|
|
462
|
2000 @cindex memory usage
|
|
|
2001
|
|
|
2002 If a program typically uses just a few meg of memory, don't bother making any
|
|
428
|
2003 effort to reduce memory usage. For example, if it is impractical for
|
|
|
2004 other reasons to operate on files more than a few meg long, it is
|
|
|
2005 reasonable to read entire input files into core to operate on them.
|
|
|
2006
|
|
|
2007 However, for programs such as @code{cat} or @code{tail}, that can
|
|
|
2008 usefully operate on very large files, it is important to avoid using a
|
|
|
2009 technique that would artificially limit the size of files it can handle.
|
|
|
2010 If a program works by lines and could be applied to arbitrary
|
|
|
2011 user-supplied input files, it should keep only a line in memory, because
|
|
|
2012 this is not very hard and users will want to be able to operate on input
|
|
|
2013 files that are bigger than will fit in core all at once.
|
|
|
2014
|
|
|
2015 If your program creates complicated data structures, just make them in
|
|
|
2016 core and give a fatal error if @code{malloc} returns zero.
|
|
|
2017
|
|
462
|
2018 @node File Usage
|
|
|
2019 @section File Usage
|
|
|
2020 @cindex file usage
|
|
|
2021
|
|
|
2022 Programs should be prepared to operate when @file{/usr} and @file{/etc}
|
|
|
2023 are read-only file systems. Thus, if the program manages log files,
|
|
|
2024 lock files, backup files, score files, or any other files which are
|
|
|
2025 modified for internal purposes, these files should not be stored in
|
|
|
2026 @file{/usr} or @file{/etc}.
|
|
|
2027
|
|
|
2028 There are two exceptions. @file{/etc} is used to store system
|
|
|
2029 configuration information; it is reasonable for a program to modify
|
|
|
2030 files in @file{/etc} when its job is to update the system configuration.
|
|
|
2031 Also, if the user explicitly asks to modify one file in a directory, it
|
|
|
2032 is reasonable for the program to store other files in the same
|
|
|
2033 directory.
|
|
|
2034
|
|
428
|
2035 @node Writing C
|
|
|
2036 @chapter Making The Best Use of C
|
|
|
2037
|
|
|
2038 This @value{CHAPTER} provides advice on how best to use the C language
|
|
|
2039 when writing GNU software.
|
|
|
2040
|
|
|
2041 @menu
|
|
|
2042 * Formatting:: Formatting Your Source Code
|
|
|
2043 * Comments:: Commenting Your Work
|
|
|
2044 * Syntactic Conventions:: Clean Use of C Constructs
|
|
|
2045 * Names:: Naming Variables and Functions
|
|
|
2046 * System Portability:: Portability between different operating systems
|
|
|
2047 * CPU Portability:: Supporting the range of CPU types
|
|
|
2048 * System Functions:: Portability and ``standard'' library functions
|
|
|
2049 * Internationalization:: Techniques for internationalization
|
|
|
2050 * Mmap:: How you can safely use @code{mmap}.
|
|
|
2051 @end menu
|
|
|
2052
|
|
|
2053 @node Formatting
|
|
|
2054 @section Formatting Your Source Code
|
|
462
|
2055 @cindex formatting source code
|
|
|
2056
|
|
|
2057 @cindex open brace
|
|
|
2058 @cindex braces, in C source
|
|
428
|
2059 It is important to put the open-brace that starts the body of a C
|
|
|
2060 function in column zero, and avoid putting any other open-brace or
|
|
|
2061 open-parenthesis or open-bracket in column zero. Several tools look
|
|
|
2062 for open-braces in column zero to find the beginnings of C functions.
|
|
|
2063 These tools will not work on code not formatted that way.
|
|
|
2064
|
|
|
2065 It is also important for function definitions to start the name of the
|
|
|
2066 function in column zero. This helps people to search for function
|
|
|
2067 definitions, and may also help certain tools recognize them. Thus,
|
|
|
2068 the proper format is this:
|
|
|
2069
|
|
|
2070 @example
|
|
|
2071 static char *
|
|
|
2072 concat (s1, s2) /* Name starts in column zero here */
|
|
|
2073 char *s1, *s2;
|
|
|
2074 @{ /* Open brace in column zero here */
|
|
|
2075 @dots{}
|
|
|
2076 @}
|
|
|
2077 @end example
|
|
|
2078
|
|
|
2079 @noindent
|
|
462
|
2080 or, if you want to use Standard C syntax, format the definition like
|
|
|
2081 this:
|
|
428
|
2082
|
|
|
2083 @example
|
|
|
2084 static char *
|
|
|
2085 concat (char *s1, char *s2)
|
|
|
2086 @{
|
|
|
2087 @dots{}
|
|
|
2088 @}
|
|
|
2089 @end example
|
|
|
2090
|
|
462
|
2091 In Standard C, if the arguments don't fit nicely on one line,
|
|
428
|
2092 split it like this:
|
|
|
2093
|
|
|
2094 @example
|
|
|
2095 int
|
|
|
2096 lots_of_args (int an_integer, long a_long, short a_short,
|
|
|
2097 double a_double, float a_float)
|
|
|
2098 @dots{}
|
|
|
2099 @end example
|
|
|
2100
|
|
462
|
2101 The rest of this section gives our recommendations for other aspects of
|
|
|
2102 C formatting style, which is also the default style of the @code{indent}
|
|
|
2103 program in version 1.2 and newer. It corresponds to the options
|
|
|
2104
|
|
|
2105 @smallexample
|
|
|
2106 -nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2
|
|
|
2107 -ndj -nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -psl -nsc -nsob
|
|
|
2108 @end smallexample
|
|
|
2109
|
|
|
2110 We don't think of these recommendations as requirements, because it
|
|
|
2111 causes no problems for users if two different programs have different
|
|
|
2112 formatting styles.
|
|
|
2113
|
|
|
2114 But whatever style you use, please use it consistently, since a mixture
|
|
|
2115 of styles within one program tends to look ugly. If you are
|
|
|
2116 contributing changes to an existing program, please follow the style of
|
|
|
2117 that program.
|
|
|
2118
|
|
|
2119 For the body of the function, our recommended style looks like this:
|
|
428
|
2120
|
|
|
2121 @example
|
|
|
2122 if (x < foo (y, z))
|
|
|
2123 haha = bar[4] + 5;
|
|
|
2124 else
|
|
|
2125 @{
|
|
|
2126 while (z)
|
|
|
2127 @{
|
|
|
2128 haha += foo (z, z);
|
|
|
2129 z--;
|
|
|
2130 @}
|
|
|
2131 return ++x + bar ();
|
|
|
2132 @}
|
|
|
2133 @end example
|
|
|
2134
|
|
462
|
2135 @cindex spaces before open-paren
|
|
428
|
2136 We find it easier to read a program when it has spaces before the
|
|
|
2137 open-parentheses and after the commas. Especially after the commas.
|
|
|
2138
|
|
|
2139 When you split an expression into multiple lines, split it
|
|
|
2140 before an operator, not after one. Here is the right way:
|
|
|
2141
|
|
462
|
2142 @cindex expressions, splitting
|
|
428
|
2143 @example
|
|
|
2144 if (foo_this_is_long && bar > win (x, y, z)
|
|
|
2145 && remaining_condition)
|
|
|
2146 @end example
|
|
|
2147
|
|
|
2148 Try to avoid having two operators of different precedence at the same
|
|
|
2149 level of indentation. For example, don't write this:
|
|
|
2150
|
|
|
2151 @example
|
|
|
2152 mode = (inmode[j] == VOIDmode
|
|
|
2153 || GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j])
|
|
|
2154 ? outmode[j] : inmode[j]);
|
|
|
2155 @end example
|
|
|
2156
|
|
|
2157 Instead, use extra parentheses so that the indentation shows the nesting:
|
|
|
2158
|
|
|
2159 @example
|
|
|
2160 mode = ((inmode[j] == VOIDmode
|
|
|
2161 || (GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j])))
|
|
|
2162 ? outmode[j] : inmode[j]);
|
|
|
2163 @end example
|
|
|
2164
|
|
|
2165 Insert extra parentheses so that Emacs will indent the code properly.
|
|
|
2166 For example, the following indentation looks nice if you do it by hand,
|
|
|
2167
|
|
|
2168 @example
|
|
|
2169 v = rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000
|
|
|
2170 + rup->ru_stime.tv_sec*1000 + rup->ru_stime.tv_usec/1000;
|
|
|
2171 @end example
|
|
|
2172
|
|
462
|
2173 @noindent
|
|
|
2174 but Emacs would alter it. Adding a set of parentheses produces
|
|
|
2175 something that looks equally nice, and which Emacs will preserve:
|
|
428
|
2176
|
|
|
2177 @example
|
|
|
2178 v = (rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000
|
|
|
2179 + rup->ru_stime.tv_sec*1000 + rup->ru_stime.tv_usec/1000);
|
|
|
2180 @end example
|
|
|
2181
|
|
|
2182 Format do-while statements like this:
|
|
|
2183
|
|
|
2184 @example
|
|
|
2185 do
|
|
|
2186 @{
|
|
|
2187 a = foo (a);
|
|
|
2188 @}
|
|
|
2189 while (a > 0);
|
|
|
2190 @end example
|
|
|
2191
|
|
462
|
2192 @cindex formfeed
|
|
|
2193 @cindex control-L
|
|
428
|
2194 Please use formfeed characters (control-L) to divide the program into
|
|
|
2195 pages at logical places (but not within a function). It does not matter
|
|
|
2196 just how long the pages are, since they do not have to fit on a printed
|
|
|
2197 page. The formfeeds should appear alone on lines by themselves.
|
|
|
2198
|
|
|
2199 @node Comments
|
|
|
2200 @section Commenting Your Work
|
|
462
|
2201 @cindex commenting
|
|
428
|
2202
|
|
|
2203 Every program should start with a comment saying briefly what it is for.
|
|
|
2204 Example: @samp{fmt - filter for simple filling of text}.
|
|
|
2205
|
|
|
2206 Please write the comments in a GNU program in English, because English
|
|
|
2207 is the one language that nearly all programmers in all countries can
|
|
|
2208 read. If you do not write English well, please write comments in
|
|
|
2209 English as well as you can, then ask other people to help rewrite them.
|
|
|
2210 If you can't write comments in English, please find someone to work with
|
|
|
2211 you and translate your comments into English.
|
|
|
2212
|
|
|
2213 Please put a comment on each function saying what the function does,
|
|
|
2214 what sorts of arguments it gets, and what the possible values of
|
|
|
2215 arguments mean and are used for. It is not necessary to duplicate in
|
|
|
2216 words the meaning of the C argument declarations, if a C type is being
|
|
|
2217 used in its customary fashion. If there is anything nonstandard about
|
|
|
2218 its use (such as an argument of type @code{char *} which is really the
|
|
|
2219 address of the second character of a string, not the first), or any
|
|
|
2220 possible values that would not work the way one would expect (such as,
|
|
|
2221 that strings containing newlines are not guaranteed to work), be sure
|
|
|
2222 to say so.
|
|
|
2223
|
|
|
2224 Also explain the significance of the return value, if there is one.
|
|
|
2225
|
|
|
2226 Please put two spaces after the end of a sentence in your comments, so
|
|
|
2227 that the Emacs sentence commands will work. Also, please write
|
|
|
2228 complete sentences and capitalize the first word. If a lower-case
|
|
|
2229 identifier comes at the beginning of a sentence, don't capitalize it!
|
|
|
2230 Changing the spelling makes it a different identifier. If you don't
|
|
|
2231 like starting a sentence with a lower case letter, write the sentence
|
|
|
2232 differently (e.g., ``The identifier lower-case is @dots{}'').
|
|
|
2233
|
|
|
2234 The comment on a function is much clearer if you use the argument
|
|
|
2235 names to speak about the argument values. The variable name itself
|
|
|
2236 should be lower case, but write it in upper case when you are speaking
|
|
|
2237 about the value rather than the variable itself. Thus, ``the inode
|
|
|
2238 number NODE_NUM'' rather than ``an inode''.
|
|
|
2239
|
|
|
2240 There is usually no purpose in restating the name of the function in
|
|
|
2241 the comment before it, because the reader can see that for himself.
|
|
|
2242 There might be an exception when the comment is so long that the function
|
|
|
2243 itself would be off the bottom of the screen.
|
|
|
2244
|
|
|
2245 There should be a comment on each static variable as well, like this:
|
|
|
2246
|
|
|
2247 @example
|
|
|
2248 /* Nonzero means truncate lines in the display;
|
|
|
2249 zero means continue them. */
|
|
|
2250 int truncate_lines;
|
|
|
2251 @end example
|
|
|
2252
|
|
462
|
2253 @cindex conditionals, comments for
|
|
|
2254 @cindex @code{#endif}, commenting
|
|
428
|
2255 Every @samp{#endif} should have a comment, except in the case of short
|
|
|
2256 conditionals (just a few lines) that are not nested. The comment should
|
|
|
2257 state the condition of the conditional that is ending, @emph{including
|
|
|
2258 its sense}. @samp{#else} should have a comment describing the condition
|
|
|
2259 @emph{and sense} of the code that follows. For example:
|
|
|
2260
|
|
|
2261 @example
|
|
|
2262 @group
|
|
|
2263 #ifdef foo
|
|
|
2264 @dots{}
|
|
|
2265 #else /* not foo */
|
|
|
2266 @dots{}
|
|
|
2267 #endif /* not foo */
|
|
|
2268 @end group
|
|
|
2269 @group
|
|
|
2270 #ifdef foo
|
|
|
2271 @dots{}
|
|
|
2272 #endif /* foo */
|
|
|
2273 @end group
|
|
|
2274 @end example
|
|
|
2275
|
|
|
2276 @noindent
|
|
|
2277 but, by contrast, write the comments this way for a @samp{#ifndef}:
|
|
|
2278
|
|
|
2279 @example
|
|
|
2280 @group
|
|
|
2281 #ifndef foo
|
|
|
2282 @dots{}
|
|
|
2283 #else /* foo */
|
|
|
2284 @dots{}
|
|
|
2285 #endif /* foo */
|
|
|
2286 @end group
|
|
|
2287 @group
|
|
|
2288 #ifndef foo
|
|
|
2289 @dots{}
|
|
|
2290 #endif /* not foo */
|
|
|
2291 @end group
|
|
|
2292 @end example
|
|
|
2293
|
|
|
2294 @node Syntactic Conventions
|
|
|
2295 @section Clean Use of C Constructs
|
|
462
|
2296 @cindex syntactic conventions
|
|
|
2297
|
|
|
2298 @cindex implicit @code{int}
|
|
|
2299 @cindex function argument, declaring
|
|
|
2300 Please explicitly declare the types of all objects. For example, you
|
|
|
2301 should explicitly declare all arguments to functions, and you should
|
|
|
2302 declare functions to return @code{int} rather than omitting the
|
|
|
2303 @code{int}.
|
|
|
2304
|
|
|
2305 @cindex compiler warnings
|
|
|
2306 @cindex @samp{-Wall} compiler option
|
|
|
2307 Some programmers like to use the GCC @samp{-Wall} option, and change the
|
|
|
2308 code whenever it issues a warning. If you want to do this, then do.
|
|
|
2309 Other programmers prefer not to use @samp{-Wall}, because it gives
|
|
|
2310 warnings for valid and legitimate code which they do not want to change.
|
|
|
2311 If you want to do this, then do. The compiler should be your servant,
|
|
|
2312 not your master.
|
|
428
|
2313
|
|
|
2314 Declarations of external functions and functions to appear later in the
|
|
|
2315 source file should all go in one place near the beginning of the file
|
|
|
2316 (somewhere before the first function definition in the file), or else
|
|
|
2317 should go in a header file. Don't put @code{extern} declarations inside
|
|
|
2318 functions.
|
|
|
2319
|
|
462
|
2320 @cindex temporary variables
|
|
428
|
2321 It used to be common practice to use the same local variables (with
|
|
|
2322 names like @code{tem}) over and over for different values within one
|
|
|
2323 function. Instead of doing this, it is better declare a separate local
|
|
|
2324 variable for each distinct purpose, and give it a name which is
|
|
|
2325 meaningful. This not only makes programs easier to understand, it also
|
|
|
2326 facilitates optimization by good compilers. You can also move the
|
|
|
2327 declaration of each local variable into the smallest scope that includes
|
|
|
2328 all its uses. This makes the program even cleaner.
|
|
|
2329
|
|
|
2330 Don't use local variables or parameters that shadow global identifiers.
|
|
|
2331
|
|
462
|
2332 @cindex multiple variables in a line
|
|
428
|
2333 Don't declare multiple variables in one declaration that spans lines.
|
|
|
2334 Start a new declaration on each line, instead. For example, instead
|
|
|
2335 of this:
|
|
|
2336
|
|
|
2337 @example
|
|
|
2338 @group
|
|
|
2339 int foo,
|
|
|
2340 bar;
|
|
|
2341 @end group
|
|
|
2342 @end example
|
|
|
2343
|
|
|
2344 @noindent
|
|
|
2345 write either this:
|
|
|
2346
|
|
|
2347 @example
|
|
|
2348 int foo, bar;
|
|
|
2349 @end example
|
|
|
2350
|
|
|
2351 @noindent
|
|
|
2352 or this:
|
|
|
2353
|
|
|
2354 @example
|
|
|
2355 int foo;
|
|
|
2356 int bar;
|
|
|
2357 @end example
|
|
|
2358
|
|
|
2359 @noindent
|
|
|
2360 (If they are global variables, each should have a comment preceding it
|
|
|
2361 anyway.)
|
|
|
2362
|
|
|
2363 When you have an @code{if}-@code{else} statement nested in another
|
|
|
2364 @code{if} statement, always put braces around the @code{if}-@code{else}.
|
|
|
2365 Thus, never write like this:
|
|
|
2366
|
|
|
2367 @example
|
|
|
2368 if (foo)
|
|
|
2369 if (bar)
|
|
|
2370 win ();
|
|
|
2371 else
|
|
|
2372 lose ();
|
|
|
2373 @end example
|
|
|
2374
|
|
|
2375 @noindent
|
|
|
2376 always like this:
|
|
|
2377
|
|
|
2378 @example
|
|
|
2379 if (foo)
|
|
|
2380 @{
|
|
|
2381 if (bar)
|
|
|
2382 win ();
|
|
|
2383 else
|
|
|
2384 lose ();
|
|
|
2385 @}
|
|
|
2386 @end example
|
|
|
2387
|
|
|
2388 If you have an @code{if} statement nested inside of an @code{else}
|
|
|
2389 statement, either write @code{else if} on one line, like this,
|
|
|
2390
|
|
|
2391 @example
|
|
|
2392 if (foo)
|
|
|
2393 @dots{}
|
|
|
2394 else if (bar)
|
|
|
2395 @dots{}
|
|
|
2396 @end example
|
|
|
2397
|
|
|
2398 @noindent
|
|
|
2399 with its @code{then}-part indented like the preceding @code{then}-part,
|
|
|
2400 or write the nested @code{if} within braces like this:
|
|
|
2401
|
|
|
2402 @example
|
|
|
2403 if (foo)
|
|
|
2404 @dots{}
|
|
|
2405 else
|
|
|
2406 @{
|
|
|
2407 if (bar)
|
|
|
2408 @dots{}
|
|
|
2409 @}
|
|
|
2410 @end example
|
|
|
2411
|
|
|
2412 Don't declare both a structure tag and variables or typedefs in the
|
|
|
2413 same declaration. Instead, declare the structure tag separately
|
|
|
2414 and then use it to declare the variables or typedefs.
|
|
|
2415
|
|
|
2416 Try to avoid assignments inside @code{if}-conditions. For example,
|
|
|
2417 don't write this:
|
|
|
2418
|
|
|
2419 @example
|
|
|
2420 if ((foo = (char *) malloc (sizeof *foo)) == 0)
|
|
|
2421 fatal ("virtual memory exhausted");
|
|
|
2422 @end example
|
|
|
2423
|
|
|
2424 @noindent
|
|
|
2425 instead, write this:
|
|
|
2426
|
|
|
2427 @example
|
|
|
2428 foo = (char *) malloc (sizeof *foo);
|
|
|
2429 if (foo == 0)
|
|
|
2430 fatal ("virtual memory exhausted");
|
|
|
2431 @end example
|
|
|
2432
|
|
462
|
2433 @pindex lint
|
|
428
|
2434 Don't make the program ugly to placate @code{lint}. Please don't insert any
|
|
|
2435 casts to @code{void}. Zero without a cast is perfectly fine as a null
|
|
|
2436 pointer constant, except when calling a varargs function.
|
|
|
2437
|
|
|
2438 @node Names
|
|
|
2439 @section Naming Variables and Functions
|
|
|
2440
|
|
462
|
2441 @cindex names of variables and functions
|
|
428
|
2442 The names of global variables and functions in a program serve as
|
|
|
2443 comments of a sort. So don't choose terse names---instead, look for
|
|
|
2444 names that give useful information about the meaning of the variable or
|
|
|
2445 function. In a GNU program, names should be English, like other
|
|
|
2446 comments.
|
|
|
2447
|
|
|
2448 Local variable names can be shorter, because they are used only within
|
|
|
2449 one context, where (presumably) comments explain their purpose.
|
|
|
2450
|
|
|
2451 Try to limit your use of abbreviations in symbol names. It is ok to
|
|
|
2452 make a few abbreviations, explain what they mean, and then use them
|
|
|
2453 frequently, but don't use lots of obscure abbreviations.
|
|
|
2454
|
|
|
2455 Please use underscores to separate words in a name, so that the Emacs
|
|
|
2456 word commands can be useful within them. Stick to lower case; reserve
|
|
|
2457 upper case for macros and @code{enum} constants, and for name-prefixes
|
|
|
2458 that follow a uniform convention.
|
|
|
2459
|
|
|
2460 For example, you should use names like @code{ignore_space_change_flag};
|
|
|
2461 don't use names like @code{iCantReadThis}.
|
|
|
2462
|
|
|
2463 Variables that indicate whether command-line options have been
|
|
|
2464 specified should be named after the meaning of the option, not after
|
|
|
2465 the option-letter. A comment should state both the exact meaning of
|
|
|
2466 the option and its letter. For example,
|
|
|
2467
|
|
|
2468 @example
|
|
|
2469 @group
|
|
|
2470 /* Ignore changes in horizontal whitespace (-b). */
|
|
|
2471 int ignore_space_change_flag;
|
|
|
2472 @end group
|
|
|
2473 @end example
|
|
|
2474
|
|
|
2475 When you want to define names with constant integer values, use
|
|
|
2476 @code{enum} rather than @samp{#define}. GDB knows about enumeration
|
|
|
2477 constants.
|
|
|
2478
|
|
462
|
2479 @cindex file-name limitations
|
|
|
2480 @pindex doschk
|
|
|
2481 You might want to make sure that none of the file names would conflict
|
|
|
2482 the files were loaded onto an MS-DOS file system which shortens the
|
|
|
2483 names. You can use the program @code{doschk} to test for this.
|
|
|
2484
|
|
|
2485 Some GNU programs were designed to limit themselves to file names of 14
|
|
|
2486 characters or less, to avoid file name conflicts if they are read into
|
|
|
2487 older System V systems. Please preserve this feature in the existing
|
|
|
2488 GNU programs that have it, but there is no need to do this in new GNU
|
|
|
2489 programs. @code{doschk} also reports file names longer than 14
|
|
|
2490 characters.
|
|
428
|
2491
|
|
|
2492 @node System Portability
|
|
|
2493 @section Portability between System Types
|
|
462
|
2494 @cindex portability, between system types
|
|
428
|
2495
|
|
|
2496 In the Unix world, ``portability'' refers to porting to different Unix
|
|
|
2497 versions. For a GNU program, this kind of portability is desirable, but
|
|
|
2498 not paramount.
|
|
|
2499
|
|
|
2500 The primary purpose of GNU software is to run on top of the GNU kernel,
|
|
462
|
2501 compiled with the GNU C compiler, on various types of @sc{cpu}. So the
|
|
|
2502 kinds of portability that are absolutely necessary are quite limited.
|
|
|
2503 But it is important to support Linux-based GNU systems, since they
|
|
|
2504 are the form of GNU that is popular.
|
|
|
2505
|
|
|
2506 Beyond that, it is good to support the other free operating systems
|
|
|
2507 (*BSD), and it is nice to support other Unix-like systems if you want
|
|
|
2508 to. Supporting a variety of Unix-like systems is desirable, although
|
|
|
2509 not paramount. It is usually not too hard, so you may as well do it.
|
|
|
2510 But you don't have to consider it an obligation, if it does turn out to
|
|
|
2511 be hard.
|
|
|
2512
|
|
|
2513 @pindex autoconf
|
|
428
|
2514 The easiest way to achieve portability to most Unix-like systems is to
|
|
|
2515 use Autoconf. It's unlikely that your program needs to know more
|
|
|
2516 information about the host platform than Autoconf can provide, simply
|
|
|
2517 because most of the programs that need such knowledge have already been
|
|
|
2518 written.
|
|
|
2519
|
|
|
2520 Avoid using the format of semi-internal data bases (e.g., directories)
|
|
|
2521 when there is a higher-level alternative (@code{readdir}).
|
|
|
2522
|
|
462
|
2523 @cindex non-@sc{posix} systems, and portability
|
|
428
|
2524 As for systems that are not like Unix, such as MSDOS, Windows, the
|
|
|
2525 Macintosh, VMS, and MVS, supporting them is often a lot of work. When
|
|
|
2526 that is the case, it is better to spend your time adding features that
|
|
|
2527 will be useful on GNU and GNU/Linux, rather than on supporting other
|
|
|
2528 incompatible systems.
|
|
|
2529
|
|
462
|
2530 It is a good idea to define the ``feature test macro''
|
|
|
2531 @code{_GNU_SOURCE} when compiling your C files. When you compile on GNU
|
|
|
2532 or GNU/Linux, this will enable the declarations of GNU library extension
|
|
|
2533 functions, and that will usually give you a compiler error message if
|
|
|
2534 you define the same function names in some other way in your program.
|
|
|
2535 (You don't have to actually @emph{use} these functions, if you prefer
|
|
|
2536 to make the program more portable to other systems.)
|
|
|
2537
|
|
|
2538 But whether or not you use these GNU extensions, you should avoid
|
|
|
2539 using their names for any other meanings. Doing so would make it hard
|
|
|
2540 to move your code into other GNU programs.
|
|
|
2541
|
|
428
|
2542 @node CPU Portability
|
|
|
2543 @section Portability between @sc{cpu}s
|
|
|
2544
|
|
462
|
2545 @cindex data types, and portability
|
|
|
2546 @cindex portability, and data types
|
|
428
|
2547 Even GNU systems will differ because of differences among @sc{cpu}
|
|
|
2548 types---for example, difference in byte ordering and alignment
|
|
|
2549 requirements. It is absolutely essential to handle these differences.
|
|
|
2550 However, don't make any effort to cater to the possibility that an
|
|
|
2551 @code{int} will be less than 32 bits. We don't support 16-bit machines
|
|
|
2552 in GNU.
|
|
|
2553
|
|
462
|
2554 Similarly, don't make any effort to cater to the possibility that
|
|
|
2555 @code{long} will be smaller than predefined types like @code{size_t}.
|
|
|
2556 For example, the following code is ok:
|
|
|
2557
|
|
|
2558 @example
|
|
|
2559 printf ("size = %lu\n", (unsigned long) sizeof array);
|
|
|
2560 printf ("diff = %ld\n", (long) (pointer2 - pointer1));
|
|
|
2561 @end example
|
|
|
2562
|
|
|
2563 1989 Standard C requires this to work, and we know of only one
|
|
|
2564 counterexample: 64-bit programs on Microsoft Windows IA-64. We will
|
|
|
2565 leave it to those who want to port GNU programs to that environment
|
|
|
2566 to figure out how to do it.
|
|
|
2567
|
|
|
2568 Predefined file-size types like @code{off_t} are an exception: they are
|
|
|
2569 longer than @code{long} on many platforms, so code like the above won't
|
|
|
2570 work with them. One way to print an @code{off_t} value portably is to
|
|
|
2571 print its digits yourself, one by one.
|
|
|
2572
|
|
428
|
2573 Don't assume that the address of an @code{int} object is also the
|
|
|
2574 address of its least-significant byte. This is false on big-endian
|
|
|
2575 machines. Thus, don't make the following mistake:
|
|
|
2576
|
|
|
2577 @example
|
|
|
2578 int c;
|
|
|
2579 @dots{}
|
|
|
2580 while ((c = getchar()) != EOF)
|
|
|
2581 write(file_descriptor, &c, 1);
|
|
|
2582 @end example
|
|
|
2583
|
|
|
2584 When calling functions, you need not worry about the difference between
|
|
|
2585 pointers of various types, or between pointers and integers. On most
|
|
|
2586 machines, there's no difference anyway. As for the few machines where
|
|
462
|
2587 there is a difference, all of them support Standard C prototypes, so you can
|
|
|
2588 use prototypes (perhaps conditionalized to be active only in Standard C)
|
|
|
2589 to make the code work on those systems.
|
|
428
|
2590
|
|
|
2591 In certain cases, it is ok to pass integer and pointer arguments
|
|
|
2592 indiscriminately to the same function, and use no prototype on any
|
|
|
2593 system. For example, many GNU programs have error-reporting functions
|
|
|
2594 that pass their arguments along to @code{printf} and friends:
|
|
|
2595
|
|
|
2596 @example
|
|
|
2597 error (s, a1, a2, a3)
|
|
|
2598 char *s;
|
|
|
2599 char *a1, *a2, *a3;
|
|
|
2600 @{
|
|
|
2601 fprintf (stderr, "error: ");
|
|
|
2602 fprintf (stderr, s, a1, a2, a3);
|
|
|
2603 @}
|
|
|
2604 @end example
|
|
|
2605
|
|
|
2606 @noindent
|
|
|
2607 In practice, this works on all machines, since a pointer is generally
|
|
462
|
2608 the widest possible kind of argument; it is much simpler than any
|
|
428
|
2609 ``correct'' alternative. Be sure @emph{not} to use a prototype for such
|
|
|
2610 functions.
|
|
|
2611
|
|
462
|
2612 If you have decided to use Standard C, then you can instead define
|
|
|
2613 @code{error} using @file{stdarg.h}, and pass the arguments along to
|
|
|
2614 @code{vfprintf}.
|
|
|
2615
|
|
|
2616 @cindex casting pointers to integers
|
|
|
2617 Avoid casting pointers to integers if you can. Such casts greatly
|
|
|
2618 reduce portability, and in most programs they are easy to avoid. In the
|
|
|
2619 cases where casting pointers to integers is essential---such as, a Lisp
|
|
|
2620 interpreter which stores type information as well as an address in one
|
|
|
2621 word---you'll have to make explicit provisions to handle different word
|
|
|
2622 sizes. You will also need to make provision for systems in which the
|
|
|
2623 normal range of addresses you can get from @code{malloc} starts far away
|
|
|
2624 from zero.
|
|
428
|
2625
|
|
|
2626 @node System Functions
|
|
|
2627 @section Calling System Functions
|
|
462
|
2628 @cindex library functions, and portability
|
|
|
2629 @cindex portability, and library functions
|
|
|
2630
|
|
|
2631 C implementations differ substantially. Standard C reduces but does
|
|
|
2632 not eliminate the incompatibilities; meanwhile, many GNU packages still
|
|
|
2633 support pre-standard compilers because this is not hard to do. This
|
|
|
2634 chapter gives recommendations for how to use the more-or-less standard C
|
|
|
2635 library functions to avoid unnecessary loss of portability.
|
|
428
|
2636
|
|
|
2637 @itemize @bullet
|
|
|
2638 @item
|
|
462
|
2639 Don't use the return value of @code{sprintf}. It returns the number of
|
|
428
|
2640 characters written on some systems, but not on all systems.
|
|
|
2641
|
|
|
2642 @item
|
|
462
|
2643 Be aware that @code{vfprintf} is not always available.
|
|
|
2644
|
|
|
2645 @item
|
|
428
|
2646 @code{main} should be declared to return type @code{int}. It should
|
|
|
2647 terminate either by calling @code{exit} or by returning the integer
|
|
|
2648 status code; make sure it cannot ever return an undefined value.
|
|
|
2649
|
|
462
|
2650 @cindex declaration for system functions
|
|
428
|
2651 @item
|
|
|
2652 Don't declare system functions explicitly.
|
|
|
2653
|
|
|
2654 Almost any declaration for a system function is wrong on some system.
|
|
|
2655 To minimize conflicts, leave it to the system header files to declare
|
|
|
2656 system functions. If the headers don't declare a function, let it
|
|
|
2657 remain undeclared.
|
|
|
2658
|
|
|
2659 While it may seem unclean to use a function without declaring it, in
|
|
|
2660 practice this works fine for most system library functions on the
|
|
|
2661 systems where this really happens; thus, the disadvantage is only
|
|
|
2662 theoretical. By contrast, actual declarations have frequently caused
|
|
|
2663 actual conflicts.
|
|
|
2664
|
|
|
2665 @item
|
|
|
2666 If you must declare a system function, don't specify the argument types.
|
|
462
|
2667 Use an old-style declaration, not a Standard C prototype. The more you
|
|
428
|
2668 specify about the function, the more likely a conflict.
|
|
|
2669
|
|
|
2670 @item
|
|
|
2671 In particular, don't unconditionally declare @code{malloc} or
|
|
|
2672 @code{realloc}.
|
|
|
2673
|
|
|
2674 Most GNU programs use those functions just once, in functions
|
|
|
2675 conventionally named @code{xmalloc} and @code{xrealloc}. These
|
|
|
2676 functions call @code{malloc} and @code{realloc}, respectively, and
|
|
|
2677 check the results.
|
|
|
2678
|
|
|
2679 Because @code{xmalloc} and @code{xrealloc} are defined in your program,
|
|
|
2680 you can declare them in other files without any risk of type conflict.
|
|
|
2681
|
|
|
2682 On most systems, @code{int} is the same length as a pointer; thus, the
|
|
|
2683 calls to @code{malloc} and @code{realloc} work fine. For the few
|
|
|
2684 exceptional systems (mostly 64-bit machines), you can use
|
|
|
2685 @strong{conditionalized} declarations of @code{malloc} and
|
|
|
2686 @code{realloc}---or put these declarations in configuration files
|
|
|
2687 specific to those systems.
|
|
|
2688
|
|
462
|
2689 @cindex string library functions
|
|
428
|
2690 @item
|
|
|
2691 The string functions require special treatment. Some Unix systems have
|
|
|
2692 a header file @file{string.h}; others have @file{strings.h}. Neither
|
|
|
2693 file name is portable. There are two things you can do: use Autoconf to
|
|
|
2694 figure out which file to include, or don't include either file.
|
|
|
2695
|
|
|
2696 @item
|
|
|
2697 If you don't include either strings file, you can't get declarations for
|
|
|
2698 the string functions from the header file in the usual way.
|
|
|
2699
|
|
462
|
2700 That causes less of a problem than you might think. The newer standard
|
|
428
|
2701 string functions should be avoided anyway because many systems still
|
|
|
2702 don't support them. The string functions you can use are these:
|
|
|
2703
|
|
|
2704 @example
|
|
|
2705 strcpy strncpy strcat strncat
|
|
|
2706 strlen strcmp strncmp
|
|
|
2707 strchr strrchr
|
|
|
2708 @end example
|
|
|
2709
|
|
|
2710 The copy and concatenate functions work fine without a declaration as
|
|
|
2711 long as you don't use their values. Using their values without a
|
|
|
2712 declaration fails on systems where the width of a pointer differs from
|
|
|
2713 the width of @code{int}, and perhaps in other cases. It is trivial to
|
|
|
2714 avoid using their values, so do that.
|
|
|
2715
|
|
|
2716 The compare functions and @code{strlen} work fine without a declaration
|
|
|
2717 on most systems, possibly all the ones that GNU software runs on.
|
|
|
2718 You may find it necessary to declare them @strong{conditionally} on a
|
|
|
2719 few systems.
|
|
|
2720
|
|
|
2721 The search functions must be declared to return @code{char *}. Luckily,
|
|
|
2722 there is no variation in the data type they return. But there is
|
|
|
2723 variation in their names. Some systems give these functions the names
|
|
|
2724 @code{index} and @code{rindex}; other systems use the names
|
|
|
2725 @code{strchr} and @code{strrchr}. Some systems support both pairs of
|
|
|
2726 names, but neither pair works on all systems.
|
|
|
2727
|
|
|
2728 You should pick a single pair of names and use it throughout your
|
|
|
2729 program. (Nowadays, it is better to choose @code{strchr} and
|
|
462
|
2730 @code{strrchr} for new programs, since those are the standard
|
|
428
|
2731 names.) Declare both of those names as functions returning @code{char
|
|
|
2732 *}. On systems which don't support those names, define them as macros
|
|
|
2733 in terms of the other pair. For example, here is what to put at the
|
|
|
2734 beginning of your file (or in a header) if you want to use the names
|
|
|
2735 @code{strchr} and @code{strrchr} throughout:
|
|
|
2736
|
|
|
2737 @example
|
|
|
2738 #ifndef HAVE_STRCHR
|
|
|
2739 #define strchr index
|
|
|
2740 #endif
|
|
|
2741 #ifndef HAVE_STRRCHR
|
|
|
2742 #define strrchr rindex
|
|
|
2743 #endif
|
|
|
2744
|
|
|
2745 char *strchr ();
|
|
|
2746 char *strrchr ();
|
|
|
2747 @end example
|
|
|
2748 @end itemize
|
|
|
2749
|
|
|
2750 Here we assume that @code{HAVE_STRCHR} and @code{HAVE_STRRCHR} are
|
|
|
2751 macros defined in systems where the corresponding functions exist.
|
|
|
2752 One way to get them properly defined is to use Autoconf.
|
|
|
2753
|
|
|
2754 @node Internationalization
|
|
|
2755 @section Internationalization
|
|
462
|
2756 @cindex internationalization
|
|
|
2757
|
|
|
2758 @pindex gettext
|
|
428
|
2759 GNU has a library called GNU gettext that makes it easy to translate the
|
|
|
2760 messages in a program into various languages. You should use this
|
|
|
2761 library in every program. Use English for the messages as they appear
|
|
|
2762 in the program, and let gettext provide the way to translate them into
|
|
|
2763 other languages.
|
|
|
2764
|
|
|
2765 Using GNU gettext involves putting a call to the @code{gettext} macro
|
|
|
2766 around each string that might need translation---like this:
|
|
|
2767
|
|
|
2768 @example
|
|
|
2769 printf (gettext ("Processing file `%s'..."));
|
|
|
2770 @end example
|
|
|
2771
|
|
|
2772 @noindent
|
|
|
2773 This permits GNU gettext to replace the string @code{"Processing file
|
|
|
2774 `%s'..."} with a translated version.
|
|
|
2775
|
|
|
2776 Once a program uses gettext, please make a point of writing calls to
|
|
|
2777 @code{gettext} when you add new strings that call for translation.
|
|
|
2778
|
|
|
2779 Using GNU gettext in a package involves specifying a @dfn{text domain
|
|
|
2780 name} for the package. The text domain name is used to separate the
|
|
|
2781 translations for this package from the translations for other packages.
|
|
|
2782 Normally, the text domain name should be the same as the name of the
|
|
|
2783 package---for example, @samp{fileutils} for the GNU file utilities.
|
|
|
2784
|
|
462
|
2785 @cindex message text, and internationalization
|
|
428
|
2786 To enable gettext to work well, avoid writing code that makes
|
|
|
2787 assumptions about the structure of words or sentences. When you want
|
|
|
2788 the precise text of a sentence to vary depending on the data, use two or
|
|
|
2789 more alternative string constants each containing a complete sentences,
|
|
|
2790 rather than inserting conditionalized words or phrases into a single
|
|
|
2791 sentence framework.
|
|
|
2792
|
|
|
2793 Here is an example of what not to do:
|
|
|
2794
|
|
|
2795 @example
|
|
|
2796 printf ("%d file%s processed", nfiles,
|
|
|
2797 nfiles != 1 ? "s" : "");
|
|
|
2798 @end example
|
|
|
2799
|
|
|
2800 @noindent
|
|
|
2801 The problem with that example is that it assumes that plurals are made
|
|
|
2802 by adding `s'. If you apply gettext to the format string, like this,
|
|
|
2803
|
|
|
2804 @example
|
|
|
2805 printf (gettext ("%d file%s processed"), nfiles,
|
|
|
2806 nfiles != 1 ? "s" : "");
|
|
|
2807 @end example
|
|
|
2808
|
|
|
2809 @noindent
|
|
|
2810 the message can use different words, but it will still be forced to use
|
|
|
2811 `s' for the plural. Here is a better way:
|
|
|
2812
|
|
|
2813 @example
|
|
|
2814 printf ((nfiles != 1 ? "%d files processed"
|
|
|
2815 : "%d file processed"),
|
|
|
2816 nfiles);
|
|
|
2817 @end example
|
|
|
2818
|
|
|
2819 @noindent
|
|
|
2820 This way, you can apply gettext to each of the two strings
|
|
|
2821 independently:
|
|
|
2822
|
|
|
2823 @example
|
|
|
2824 printf ((nfiles != 1 ? gettext ("%d files processed")
|
|
|
2825 : gettext ("%d file processed")),
|
|
|
2826 nfiles);
|
|
|
2827 @end example
|
|
|
2828
|
|
|
2829 @noindent
|
|
|
2830 This can be any method of forming the plural of the word for ``file'', and
|
|
|
2831 also handles languages that require agreement in the word for
|
|
|
2832 ``processed''.
|
|
|
2833
|
|
|
2834 A similar problem appears at the level of sentence structure with this
|
|
|
2835 code:
|
|
|
2836
|
|
|
2837 @example
|
|
|
2838 printf ("# Implicit rule search has%s been done.\n",
|
|
|
2839 f->tried_implicit ? "" : " not");
|
|
|
2840 @end example
|
|
|
2841
|
|
|
2842 @noindent
|
|
|
2843 Adding @code{gettext} calls to this code cannot give correct results for
|
|
|
2844 all languages, because negation in some languages requires adding words
|
|
|
2845 at more than one place in the sentence. By contrast, adding
|
|
|
2846 @code{gettext} calls does the job straightfowardly if the code starts
|
|
|
2847 out like this:
|
|
|
2848
|
|
|
2849 @example
|
|
|
2850 printf (f->tried_implicit
|
|
|
2851 ? "# Implicit rule search has been done.\n",
|
|
|
2852 : "# Implicit rule search has not been done.\n");
|
|
|
2853 @end example
|
|
|
2854
|
|
|
2855 @node Mmap
|
|
|
2856 @section Mmap
|
|
462
|
2857 @findex mmap
|
|
428
|
2858
|
|
|
2859 Don't assume that @code{mmap} either works on all files or fails
|
|
|
2860 for all files. It may work on some files and fail on others.
|
|
|
2861
|
|
|
2862 The proper way to use @code{mmap} is to try it on the specific file for
|
|
|
2863 which you want to use it---and if @code{mmap} doesn't work, fall back on
|
|
|
2864 doing the job in another way using @code{read} and @code{write}.
|
|
|
2865
|
|
|
2866 The reason this precaution is needed is that the GNU kernel (the HURD)
|
|
|
2867 provides a user-extensible file system, in which there can be many
|
|
|
2868 different kinds of ``ordinary files.'' Many of them support
|
|
|
2869 @code{mmap}, but some do not. It is important to make programs handle
|
|
|
2870 all these kinds of files.
|
|
|
2871
|
|
|
2872 @node Documentation
|
|
|
2873 @chapter Documenting Programs
|
|
462
|
2874 @cindex documentation
|
|
|
2875
|
|
|
2876 A GNU program should ideally come with full free documentation, adequate
|
|
|
2877 for both reference and tutorial purposes. If the package can be
|
|
|
2878 programmed or extended, the documentation should cover programming or
|
|
|
2879 extending it, as well as just using it.
|
|
428
|
2880
|
|
|
2881 @menu
|
|
|
2882 * GNU Manuals:: Writing proper manuals.
|
|
462
|
2883 * Doc Strings and Manuals:: Compiling doc strings doesn't make a manual.
|
|
428
|
2884 * Manual Structure Details:: Specific structure conventions.
|
|
|
2885 * License for Manuals:: Writing the distribution terms for a manual.
|
|
462
|
2886 * Manual Credits:: Giving credit to documentation contributors.
|
|
|
2887 * Printed Manuals:: Mentioning the printed manual.
|
|
428
|
2888 * NEWS File:: NEWS files supplement manuals.
|
|
|
2889 * Change Logs:: Recording Changes
|
|
|
2890 * Man Pages:: Man pages are secondary.
|
|
|
2891 * Reading other Manuals:: How far you can go in learning
|
|
|
2892 from other manuals.
|
|
|
2893 @end menu
|
|
|
2894
|
|
|
2895 @node GNU Manuals
|
|
|
2896 @section GNU Manuals
|
|
|
2897
|
|
462
|
2898 The preferred document format for the GNU system is the Texinfo
|
|
|
2899 formatting language. Every GNU package should (ideally) have
|
|
|
2900 documentation in Texinfo both for reference and for learners. Texinfo
|
|
|
2901 makes it possible to produce a good quality formatted book, using
|
|
|
2902 @TeX{}, and to generate an Info file. It is also possible to generate
|
|
|
2903 HTML output from Texinfo source. See the Texinfo manual, either the
|
|
|
2904 hardcopy, or the on-line version available through @code{info} or the
|
|
|
2905 Emacs Info subsystem (@kbd{C-h i}).
|
|
|
2906
|
|
|
2907 Nowadays some other formats such as Docbook and Sgmltexi can be
|
|
|
2908 converted automatically into Texinfo. It is ok to produce the Texinfo
|
|
|
2909 documentation by conversion this way, as long as it gives good results.
|
|
428
|
2910
|
|
|
2911 Programmers often find it most natural to structure the documentation
|
|
|
2912 following the structure of the implementation, which they know. But
|
|
|
2913 this structure is not necessarily good for explaining how to use the
|
|
|
2914 program; it may be irrelevant and confusing for a user.
|
|
|
2915
|
|
|
2916 At every level, from the sentences in a paragraph to the grouping of
|
|
|
2917 topics into separate manuals, the right way to structure documentation
|
|
|
2918 is according to the concepts and questions that a user will have in mind
|
|
|
2919 when reading it. Sometimes this structure of ideas matches the
|
|
|
2920 structure of the implementation of the software being documented---but
|
|
|
2921 often they are different. Often the most important part of learning to
|
|
|
2922 write good documentation is learning to notice when you are structuring
|
|
|
2923 the documentation like the implementation, and think about better
|
|
|
2924 alternatives.
|
|
|
2925
|
|
|
2926 For example, each program in the GNU system probably ought to be
|
|
|
2927 documented in one manual; but this does not mean each program should
|
|
|
2928 have its own manual. That would be following the structure of the
|
|
|
2929 implementation, rather than the structure that helps the user
|
|
|
2930 understand.
|
|
|
2931
|
|
|
2932 Instead, each manual should cover a coherent @emph{topic}. For example,
|
|
|
2933 instead of a manual for @code{diff} and a manual for @code{diff3}, we
|
|
|
2934 have one manual for ``comparison of files'' which covers both of those
|
|
|
2935 programs, as well as @code{cmp}. By documenting these programs
|
|
|
2936 together, we can make the whole subject clearer.
|
|
|
2937
|
|
462
|
2938 The manual which discusses a program should certainly document all of
|
|
|
2939 the program's command-line options and all of its commands. It should
|
|
|
2940 give examples of their use. But don't organize the manual as a list of
|
|
428
|
2941 features. Instead, organize it logically, by subtopics. Address the
|
|
|
2942 questions that a user will ask when thinking about the job that the
|
|
|
2943 program does.
|
|
|
2944
|
|
|
2945 In general, a GNU manual should serve both as tutorial and reference.
|
|
|
2946 It should be set up for convenient access to each topic through Info,
|
|
|
2947 and for reading straight through (appendixes aside). A GNU manual
|
|
|
2948 should give a good introduction to a beginner reading through from the
|
|
|
2949 start, and should also provide all the details that hackers want.
|
|
|
2950 The Bison manual is a good example of this---please take a look at it
|
|
|
2951 to see what we mean.
|
|
|
2952
|
|
|
2953 That is not as hard as it first sounds. Arrange each chapter as a
|
|
|
2954 logical breakdown of its topic, but order the sections, and write their
|
|
|
2955 text, so that reading the chapter straight through makes sense. Do
|
|
|
2956 likewise when structuring the book into chapters, and when structuring a
|
|
|
2957 section into paragraphs. The watchword is, @emph{at each point, address
|
|
|
2958 the most fundamental and important issue raised by the preceding text.}
|
|
|
2959
|
|
|
2960 If necessary, add extra chapters at the beginning of the manual which
|
|
|
2961 are purely tutorial and cover the basics of the subject. These provide
|
|
|
2962 the framework for a beginner to understand the rest of the manual. The
|
|
|
2963 Bison manual provides a good example of how to do this.
|
|
|
2964
|
|
462
|
2965 To serve as a reference, a manual should have an Index that list all the
|
|
|
2966 functions, variables, options, and important concepts that are part of
|
|
|
2967 the program. One combined Index should do for a short manual, but
|
|
|
2968 sometimes for a complex package it is better to use multiple indices.
|
|
|
2969 The Texinfo manual includes advice on preparing good index entries, see
|
|
|
2970 @ref{Index Entries, , Making Index Entries, texinfo, The GNU Texinfo
|
|
|
2971 Manual}, and see @ref{Indexing Commands, , Defining the Entries of an
|
|
|
2972 Index, texinfo, The GNU Texinfo manual}.
|
|
|
2973
|
|
428
|
2974 Don't use Unix man pages as a model for how to write GNU documentation;
|
|
|
2975 most of them are terse, badly structured, and give inadequate
|
|
462
|
2976 explanation of the underlying concepts. (There are, of course, some
|
|
|
2977 exceptions.) Also, Unix man pages use a particular format which is
|
|
428
|
2978 different from what we use in GNU manuals.
|
|
|
2979
|
|
|
2980 Please include an email address in the manual for where to report
|
|
|
2981 bugs @emph{in the manual}.
|
|
|
2982
|
|
|
2983 Please do not use the term ``pathname'' that is used in Unix
|
|
|
2984 documentation; use ``file name'' (two words) instead. We use the term
|
|
|
2985 ``path'' only for search paths, which are lists of directory names.
|
|
|
2986
|
|
|
2987 Please do not use the term ``illegal'' to refer to erroneous input to a
|
|
|
2988 computer program. Please use ``invalid'' for this, and reserve the term
|
|
462
|
2989 ``illegal'' for activities punishable by law.
|
|
|
2990
|
|
|
2991 @node Doc Strings and Manuals
|
|
|
2992 @section Doc Strings and Manuals
|
|
|
2993
|
|
|
2994 Some programming systems, such as Emacs, provide a documentation string
|
|
|
2995 for each function, command or variable. You may be tempted to write a
|
|
|
2996 reference manual by compiling the documentation strings and writing a
|
|
|
2997 little additional text to go around them---but you must not do it. That
|
|
|
2998 approach is a fundamental mistake. The text of well-written
|
|
|
2999 documentation strings will be entirely wrong for a manual.
|
|
|
3000
|
|
|
3001 A documentation string needs to stand alone---when it appears on the
|
|
|
3002 screen, there will be no other text to introduce or explain it.
|
|
|
3003 Meanwhile, it can be rather informal in style.
|
|
|
3004
|
|
|
3005 The text describing a function or variable in a manual must not stand
|
|
|
3006 alone; it appears in the context of a section or subsection. Other text
|
|
|
3007 at the beginning of the section should explain some of the concepts, and
|
|
|
3008 should often make some general points that apply to several functions or
|
|
|
3009 variables. The previous descriptions of functions and variables in the
|
|
|
3010 section will also have given information about the topic. A description
|
|
|
3011 written to stand alone would repeat some of that information; this
|
|
|
3012 redundance looks bad. Meanwhile, the informality that is acceptable in
|
|
|
3013 a documentation string is totally unacceptable in a manual.
|
|
|
3014
|
|
|
3015 The only good way to use documentation strings in writing a good manual
|
|
|
3016 is to use them as a source of information for writing good text.
|
|
428
|
3017
|
|
|
3018 @node Manual Structure Details
|
|
|
3019 @section Manual Structure Details
|
|
462
|
3020 @cindex manual structure
|
|
428
|
3021
|
|
|
3022 The title page of the manual should state the version of the programs or
|
|
|
3023 packages documented in the manual. The Top node of the manual should
|
|
|
3024 also contain this information. If the manual is changing more
|
|
|
3025 frequently than or independent of the program, also state a version
|
|
|
3026 number for the manual in both of these places.
|
|
|
3027
|
|
|
3028 Each program documented in the manual should have a node named
|
|
|
3029 @samp{@var{program} Invocation} or @samp{Invoking @var{program}}. This
|
|
|
3030 node (together with its subnodes, if any) should describe the program's
|
|
|
3031 command line arguments and how to run it (the sort of information people
|
|
|
3032 would look in a man page for). Start with an @samp{@@example}
|
|
|
3033 containing a template for all the options and arguments that the program
|
|
|
3034 uses.
|
|
|
3035
|
|
|
3036 Alternatively, put a menu item in some menu whose item name fits one of
|
|
|
3037 the above patterns. This identifies the node which that item points to
|
|
|
3038 as the node for this purpose, regardless of the node's actual name.
|
|
|
3039
|
|
462
|
3040 The @samp{--usage} feature of the Info reader looks for such a node
|
|
|
3041 or menu item in order to find the relevant text, so it is essential
|
|
|
3042 for every Texinfo file to have one.
|
|
428
|
3043
|
|
|
3044 If one manual describes several programs, it should have such a node for
|
|
462
|
3045 each program described in the manual.
|
|
428
|
3046
|
|
|
3047 @node License for Manuals
|
|
|
3048 @section License for Manuals
|
|
462
|
3049 @cindex license for manuals
|
|
|
3050
|
|
|
3051 Please use the GNU Free Documentation License for all GNU manuals that
|
|
|
3052 are more than a few pages long. Likewise for a collection of short
|
|
|
3053 documents---you only need one copy of the GNU FDL for the whole
|
|
|
3054 collection. For a single short document, you can use a very permissive
|
|
|
3055 non-copyleft license, to avoid taking up space with a long license.
|
|
|
3056
|
|
|
3057 See @uref{http://www.gnu.org/copyleft/fdl-howto.html} for more explanation
|
|
|
3058 of how to employ the GFDL.
|
|
|
3059
|
|
|
3060 Note that it is not obligatory to include a copy of the GNU GPL or GNU
|
|
|
3061 LGPL in a manual whose license is neither the GPL nor the LGPL. It can
|
|
|
3062 be a good idea to include the program's license in a large manual; in a
|
|
|
3063 short manual, whose size would be increased considerably by including
|
|
|
3064 the program's license, it is probably better not to include it.
|
|
|
3065
|
|
|
3066 @node Manual Credits
|
|
|
3067 @section Manual Credits
|
|
|
3068 @cindex credits for manuals
|
|
|
3069
|
|
|
3070 Please credit the principal human writers of the manual as the authors,
|
|
|
3071 on the title page of the manual. If a company sponsored the work, thank
|
|
|
3072 the company in a suitable place in the manual, but do not cite the
|
|
|
3073 company as an author.
|
|
|
3074
|
|
|
3075 @node Printed Manuals
|
|
|
3076 @section Printed Manuals
|
|
|
3077
|
|
|
3078 The FSF publishes some GNU manuals in printed form. To encourage sales
|
|
|
3079 of these manuals, the on-line versions of the manual should mention at
|
|
|
3080 the very start that the printed manual is available and should point at
|
|
|
3081 information for getting it---for instance, with a link to the page
|
|
|
3082 @url{http://www.gnu.org/order/order.html}. This should not be included
|
|
|
3083 in the printed manual, though, because there it is redundant.
|
|
|
3084
|
|
|
3085 It is also useful to explain in the on-line forms of the manual how the
|
|
|
3086 user can print out the manual from the sources.
|
|
428
|
3087
|
|
|
3088 @node NEWS File
|
|
|
3089 @section The NEWS File
|
|
462
|
3090 @cindex @file{NEWS} file
|
|
428
|
3091
|
|
|
3092 In addition to its manual, the package should have a file named
|
|
|
3093 @file{NEWS} which contains a list of user-visible changes worth
|
|
|
3094 mentioning. In each new release, add items to the front of the file and
|
|
|
3095 identify the version they pertain to. Don't discard old items; leave
|
|
|
3096 them in the file after the newer items. This way, a user upgrading from
|
|
|
3097 any previous version can see what is new.
|
|
|
3098
|
|
|
3099 If the @file{NEWS} file gets very long, move some of the older items
|
|
|
3100 into a file named @file{ONEWS} and put a note at the end referring the
|
|
|
3101 user to that file.
|
|
|
3102
|
|
|
3103 @node Change Logs
|
|
|
3104 @section Change Logs
|
|
462
|
3105 @cindex change logs
|
|
428
|
3106
|
|
|
3107 Keep a change log to describe all the changes made to program source
|
|
|
3108 files. The purpose of this is so that people investigating bugs in the
|
|
|
3109 future will know about the changes that might have introduced the bug.
|
|
|
3110 Often a new bug can be found by looking at what was recently changed.
|
|
|
3111 More importantly, change logs can help you eliminate conceptual
|
|
|
3112 inconsistencies between different parts of a program, by giving you a
|
|
|
3113 history of how the conflicting concepts arose and who they came from.
|
|
|
3114
|
|
|
3115 @menu
|
|
|
3116 * Change Log Concepts::
|
|
|
3117 * Style of Change Logs::
|
|
|
3118 * Simple Changes::
|
|
|
3119 * Conditional Changes::
|
|
462
|
3120 * Indicating the Part Changed::
|
|
428
|
3121 @end menu
|
|
|
3122
|
|
|
3123 @node Change Log Concepts
|
|
|
3124 @subsection Change Log Concepts
|
|
|
3125
|
|
|
3126 You can think of the change log as a conceptual ``undo list'' which
|
|
|
3127 explains how earlier versions were different from the current version.
|
|
|
3128 People can see the current version; they don't need the change log
|
|
|
3129 to tell them what is in it. What they want from a change log is a
|
|
|
3130 clear explanation of how the earlier version differed.
|
|
|
3131
|
|
|
3132 The change log file is normally called @file{ChangeLog} and covers an
|
|
|
3133 entire directory. Each directory can have its own change log, or a
|
|
|
3134 directory can use the change log of its parent directory--it's up to
|
|
|
3135 you.
|
|
|
3136
|
|
|
3137 Another alternative is to record change log information with a version
|
|
|
3138 control system such as RCS or CVS. This can be converted automatically
|
|
|
3139 to a @file{ChangeLog} file using @code{rcs2log}; in Emacs, the command
|
|
|
3140 @kbd{C-x v a} (@code{vc-update-change-log}) does the job.
|
|
|
3141
|
|
|
3142 There's no need to describe the full purpose of the changes or how they
|
|
|
3143 work together. If you think that a change calls for explanation, you're
|
|
|
3144 probably right. Please do explain it---but please put the explanation
|
|
|
3145 in comments in the code, where people will see it whenever they see the
|
|
|
3146 code. For example, ``New function'' is enough for the change log when
|
|
|
3147 you add a function, because there should be a comment before the
|
|
|
3148 function definition to explain what it does.
|
|
|
3149
|
|
|
3150 However, sometimes it is useful to write one line to describe the
|
|
|
3151 overall purpose of a batch of changes.
|
|
|
3152
|
|
|
3153 The easiest way to add an entry to @file{ChangeLog} is with the Emacs
|
|
|
3154 command @kbd{M-x add-change-log-entry}. An entry should have an
|
|
|
3155 asterisk, the name of the changed file, and then in parentheses the name
|
|
|
3156 of the changed functions, variables or whatever, followed by a colon.
|
|
|
3157 Then describe the changes you made to that function or variable.
|
|
|
3158
|
|
|
3159 @node Style of Change Logs
|
|
|
3160 @subsection Style of Change Logs
|
|
462
|
3161 @cindex change logs, style
|
|
|
3162
|
|
|
3163 Here are some simple examples of change log entries, starting with the
|
|
|
3164 header line that says who made the change and when, followed by
|
|
|
3165 descriptions of specific changes. (These examples are drawn from Emacs
|
|
|
3166 and GCC.)
|
|
428
|
3167
|
|
|
3168 @example
|
|
462
|
3169 1998-08-17 Richard Stallman <rms@@gnu.org>
|
|
|
3170
|
|
428
|
3171 * register.el (insert-register): Return nil.
|
|
|
3172 (jump-to-register): Likewise.
|
|
|
3173
|
|
|
3174 * sort.el (sort-subr): Return nil.
|
|
|
3175
|
|
|
3176 * tex-mode.el (tex-bibtex-file, tex-file, tex-region):
|
|
|
3177 Restart the tex shell if process is gone or stopped.
|
|
|
3178 (tex-shell-running): New function.
|
|
|
3179
|
|
|
3180 * expr.c (store_one_arg): Round size up for move_block_to_reg.
|
|
|
3181 (expand_call): Round up when emitting USE insns.
|
|
|
3182 * stmt.c (assign_parms): Round size up for move_block_from_reg.
|
|
|
3183 @end example
|
|
|
3184
|
|
|
3185 It's important to name the changed function or variable in full. Don't
|
|
|
3186 abbreviate function or variable names, and don't combine them.
|
|
|
3187 Subsequent maintainers will often search for a function name to find all
|
|
|
3188 the change log entries that pertain to it; if you abbreviate the name,
|
|
|
3189 they won't find it when they search.
|
|
|
3190
|
|
|
3191 For example, some people are tempted to abbreviate groups of function
|
|
|
3192 names by writing @samp{* register.el (@{insert,jump-to@}-register)};
|
|
|
3193 this is not a good idea, since searching for @code{jump-to-register} or
|
|
|
3194 @code{insert-register} would not find that entry.
|
|
|
3195
|
|
|
3196 Separate unrelated change log entries with blank lines. When two
|
|
|
3197 entries represent parts of the same change, so that they work together,
|
|
|
3198 then don't put blank lines between them. Then you can omit the file
|
|
|
3199 name and the asterisk when successive entries are in the same file.
|
|
|
3200
|
|
462
|
3201 Break long lists of function names by closing continued lines with
|
|
|
3202 @samp{)}, rather than @samp{,}, and opening the continuation with
|
|
|
3203 @samp{(} as in this example:
|
|
|
3204
|
|
|
3205 @example
|
|
|
3206 * keyboard.c (menu_bar_items, tool_bar_items)
|
|
|
3207 (Fexecute_extended_command): Deal with `keymap' property.
|
|
|
3208 @end example
|
|
|
3209
|
|
428
|
3210 @node Simple Changes
|
|
|
3211 @subsection Simple Changes
|
|
|
3212
|
|
|
3213 Certain simple kinds of changes don't need much detail in the change
|
|
|
3214 log.
|
|
|
3215
|
|
|
3216 When you change the calling sequence of a function in a simple fashion,
|
|
462
|
3217 and you change all the callers of the function to use the new calling
|
|
|
3218 sequence, there is no need to make individual entries for all the
|
|
|
3219 callers that you changed. Just write in the entry for the function
|
|
|
3220 being called, ``All callers changed''---like this:
|
|
428
|
3221
|
|
|
3222 @example
|
|
|
3223 * keyboard.c (Fcommand_execute): New arg SPECIAL.
|
|
|
3224 All callers changed.
|
|
|
3225 @end example
|
|
|
3226
|
|
|
3227 When you change just comments or doc strings, it is enough to write an
|
|
|
3228 entry for the file, without mentioning the functions. Just ``Doc
|
|
|
3229 fixes'' is enough for the change log.
|
|
|
3230
|
|
|
3231 There's no need to make change log entries for documentation files.
|
|
|
3232 This is because documentation is not susceptible to bugs that are hard
|
|
|
3233 to fix. Documentation does not consist of parts that must interact in a
|
|
|
3234 precisely engineered fashion. To correct an error, you need not know
|
|
|
3235 the history of the erroneous passage; it is enough to compare what the
|
|
|
3236 documentation says with the way the program actually works.
|
|
|
3237
|
|
|
3238 @node Conditional Changes
|
|
|
3239 @subsection Conditional Changes
|
|
462
|
3240 @cindex conditional changes, and change logs
|
|
|
3241 @cindex change logs, conditional changes
|
|
428
|
3242
|
|
|
3243 C programs often contain compile-time @code{#if} conditionals. Many
|
|
|
3244 changes are conditional; sometimes you add a new definition which is
|
|
|
3245 entirely contained in a conditional. It is very useful to indicate in
|
|
|
3246 the change log the conditions for which the change applies.
|
|
|
3247
|
|
|
3248 Our convention for indicating conditional changes is to use square
|
|
|
3249 brackets around the name of the condition.
|
|
|
3250
|
|
|
3251 Here is a simple example, describing a change which is conditional but
|
|
|
3252 does not have a function or entity name associated with it:
|
|
|
3253
|
|
|
3254 @example
|
|
|
3255 * xterm.c [SOLARIS2]: Include string.h.
|
|
|
3256 @end example
|
|
|
3257
|
|
|
3258 Here is an entry describing a new definition which is entirely
|
|
|
3259 conditional. This new definition for the macro @code{FRAME_WINDOW_P} is
|
|
|
3260 used only when @code{HAVE_X_WINDOWS} is defined:
|
|
|
3261
|
|
|
3262 @example
|
|
|
3263 * frame.h [HAVE_X_WINDOWS] (FRAME_WINDOW_P): Macro defined.
|
|
|
3264 @end example
|
|
|
3265
|
|
|
3266 Here is an entry for a change within the function @code{init_display},
|
|
|
3267 whose definition as a whole is unconditional, but the changes themselves
|
|
|
3268 are contained in a @samp{#ifdef HAVE_LIBNCURSES} conditional:
|
|
|
3269
|
|
|
3270 @example
|
|
|
3271 * dispnew.c (init_display) [HAVE_LIBNCURSES]: If X, call tgetent.
|
|
|
3272 @end example
|
|
|
3273
|
|
|
3274 Here is an entry for a change that takes affect only when
|
|
|
3275 a certain macro is @emph{not} defined:
|
|
|
3276
|
|
|
3277 @example
|
|
|
3278 (gethostname) [!HAVE_SOCKETS]: Replace with winsock version.
|
|
|
3279 @end example
|
|
|
3280
|
|
462
|
3281 @node Indicating the Part Changed
|
|
|
3282 @subsection Indicating the Part Changed
|
|
|
3283
|
|
|
3284 Indicate the part of a function which changed by using angle brackets
|
|
|
3285 enclosing an indication of what the changed part does. Here is an entry
|
|
|
3286 for a change in the part of the function @code{sh-while-getopts} that
|
|
|
3287 deals with @code{sh} commands:
|
|
|
3288
|
|
|
3289 @example
|
|
|
3290 * progmodes/sh-script.el (sh-while-getopts) <sh>: Handle case that
|
|
|
3291 user-specified option string is empty.
|
|
|
3292 @end example
|
|
|
3293
|
|
|
3294
|
|
428
|
3295 @node Man Pages
|
|
|
3296 @section Man Pages
|
|
462
|
3297 @cindex man pages
|
|
428
|
3298
|
|
|
3299 In the GNU project, man pages are secondary. It is not necessary or
|
|
|
3300 expected for every GNU program to have a man page, but some of them do.
|
|
|
3301 It's your choice whether to include a man page in your program.
|
|
|
3302
|
|
|
3303 When you make this decision, consider that supporting a man page
|
|
|
3304 requires continual effort each time the program is changed. The time
|
|
|
3305 you spend on the man page is time taken away from more useful work.
|
|
|
3306
|
|
|
3307 For a simple program which changes little, updating the man page may be
|
|
|
3308 a small job. Then there is little reason not to include a man page, if
|
|
|
3309 you have one.
|
|
|
3310
|
|
|
3311 For a large program that changes a great deal, updating a man page may
|
|
|
3312 be a substantial burden. If a user offers to donate a man page, you may
|
|
|
3313 find this gift costly to accept. It may be better to refuse the man
|
|
|
3314 page unless the same person agrees to take full responsibility for
|
|
|
3315 maintaining it---so that you can wash your hands of it entirely. If
|
|
|
3316 this volunteer later ceases to do the job, then don't feel obliged to
|
|
|
3317 pick it up yourself; it may be better to withdraw the man page from the
|
|
|
3318 distribution until someone else agrees to update it.
|
|
|
3319
|
|
|
3320 When a program changes only a little, you may feel that the
|
|
|
3321 discrepancies are small enough that the man page remains useful without
|
|
|
3322 updating. If so, put a prominent note near the beginning of the man
|
|
|
3323 page explaining that you don't maintain it and that the Texinfo manual
|
|
|
3324 is more authoritative. The note should say how to access the Texinfo
|
|
|
3325 documentation.
|
|
|
3326
|
|
|
3327 @node Reading other Manuals
|
|
|
3328 @section Reading other Manuals
|
|
|
3329
|
|
|
3330 There may be non-free books or documentation files that describe the
|
|
|
3331 program you are documenting.
|
|
|
3332
|
|
|
3333 It is ok to use these documents for reference, just as the author of a
|
|
|
3334 new algebra textbook can read other books on algebra. A large portion
|
|
|
3335 of any non-fiction book consists of facts, in this case facts about how
|
|
|
3336 a certain program works, and these facts are necessarily the same for
|
|
|
3337 everyone who writes about the subject. But be careful not to copy your
|
|
|
3338 outline structure, wording, tables or examples from preexisting non-free
|
|
|
3339 documentation. Copying from free documentation may be ok; please check
|
|
|
3340 with the FSF about the individual case.
|
|
|
3341
|
|
|
3342 @node Managing Releases
|
|
|
3343 @chapter The Release Process
|
|
462
|
3344 @cindex releasing
|
|
428
|
3345
|
|
|
3346 Making a release is more than just bundling up your source files in a
|
|
|
3347 tar file and putting it up for FTP. You should set up your software so
|
|
|
3348 that it can be configured to run on a variety of systems. Your Makefile
|
|
|
3349 should conform to the GNU standards described below, and your directory
|
|
|
3350 layout should also conform to the standards discussed below. Doing so
|
|
|
3351 makes it easy to include your package into the larger framework of
|
|
|
3352 all GNU software.
|
|
|
3353
|
|
|
3354 @menu
|
|
|
3355 * Configuration:: How Configuration Should Work
|
|
|
3356 * Makefile Conventions:: Makefile Conventions
|
|
|
3357 * Releases:: Making Releases
|
|
|
3358 @end menu
|
|
|
3359
|
|
|
3360 @node Configuration
|
|
|
3361 @section How Configuration Should Work
|
|
462
|
3362 @cindex program configuration
|
|
|
3363
|
|
|
3364 @pindex configure
|
|
428
|
3365 Each GNU distribution should come with a shell script named
|
|
|
3366 @code{configure}. This script is given arguments which describe the
|
|
|
3367 kind of machine and system you want to compile the program for.
|
|
|
3368
|
|
|
3369 The @code{configure} script must record the configuration options so
|
|
|
3370 that they affect compilation.
|
|
|
3371
|
|
|
3372 One way to do this is to make a link from a standard name such as
|
|
|
3373 @file{config.h} to the proper configuration file for the chosen system.
|
|
|
3374 If you use this technique, the distribution should @emph{not} contain a
|
|
|
3375 file named @file{config.h}. This is so that people won't be able to
|
|
|
3376 build the program without configuring it first.
|
|
|
3377
|
|
|
3378 Another thing that @code{configure} can do is to edit the Makefile. If
|
|
|
3379 you do this, the distribution should @emph{not} contain a file named
|
|
|
3380 @file{Makefile}. Instead, it should include a file @file{Makefile.in} which
|
|
|
3381 contains the input used for editing. Once again, this is so that people
|
|
|
3382 won't be able to build the program without configuring it first.
|
|
|
3383
|
|
|
3384 If @code{configure} does write the @file{Makefile}, then @file{Makefile}
|
|
|
3385 should have a target named @file{Makefile} which causes @code{configure}
|
|
|
3386 to be rerun, setting up the same configuration that was set up last
|
|
|
3387 time. The files that @code{configure} reads should be listed as
|
|
|
3388 dependencies of @file{Makefile}.
|
|
|
3389
|
|
|
3390 All the files which are output from the @code{configure} script should
|
|
|
3391 have comments at the beginning explaining that they were generated
|
|
|
3392 automatically using @code{configure}. This is so that users won't think
|
|
|
3393 of trying to edit them by hand.
|
|
|
3394
|
|
|
3395 The @code{configure} script should write a file named @file{config.status}
|
|
|
3396 which describes which configuration options were specified when the
|
|
|
3397 program was last configured. This file should be a shell script which,
|
|
|
3398 if run, will recreate the same configuration.
|
|
|
3399
|
|
|
3400 The @code{configure} script should accept an option of the form
|
|
|
3401 @samp{--srcdir=@var{dirname}} to specify the directory where sources are found
|
|
|
3402 (if it is not the current directory). This makes it possible to build
|
|
|
3403 the program in a separate directory, so that the actual source directory
|
|
|
3404 is not modified.
|
|
|
3405
|
|
|
3406 If the user does not specify @samp{--srcdir}, then @code{configure} should
|
|
|
3407 check both @file{.} and @file{..} to see if it can find the sources. If
|
|
|
3408 it finds the sources in one of these places, it should use them from
|
|
|
3409 there. Otherwise, it should report that it cannot find the sources, and
|
|
|
3410 should exit with nonzero status.
|
|
|
3411
|
|
|
3412 Usually the easy way to support @samp{--srcdir} is by editing a
|
|
|
3413 definition of @code{VPATH} into the Makefile. Some rules may need to
|
|
|
3414 refer explicitly to the specified source directory. To make this
|
|
|
3415 possible, @code{configure} can add to the Makefile a variable named
|
|
|
3416 @code{srcdir} whose value is precisely the specified directory.
|
|
|
3417
|
|
|
3418 The @code{configure} script should also take an argument which specifies the
|
|
|
3419 type of system to build the program for. This argument should look like
|
|
|
3420 this:
|
|
|
3421
|
|
|
3422 @example
|
|
|
3423 @var{cpu}-@var{company}-@var{system}
|
|
|
3424 @end example
|
|
|
3425
|
|
|
3426 For example, a Sun 3 might be @samp{m68k-sun-sunos4.1}.
|
|
|
3427
|
|
|
3428 The @code{configure} script needs to be able to decode all plausible
|
|
|
3429 alternatives for how to describe a machine. Thus, @samp{sun3-sunos4.1}
|
|
|
3430 would be a valid alias. For many programs, @samp{vax-dec-ultrix} would
|
|
|
3431 be an alias for @samp{vax-dec-bsd}, simply because the differences
|
|
462
|
3432 between Ultrix and @sc{bsd} are rarely noticeable, but a few programs
|
|
428
|
3433 might need to distinguish them.
|
|
|
3434 @c Real 4.4BSD now runs on some Suns.
|
|
|
3435
|
|
|
3436 There is a shell script called @file{config.sub} that you can use
|
|
|
3437 as a subroutine to validate system types and canonicalize aliases.
|
|
|
3438
|
|
462
|
3439 @cindex optional features, configure-time
|
|
428
|
3440 Other options are permitted to specify in more detail the software
|
|
|
3441 or hardware present on the machine, and include or exclude optional
|
|
|
3442 parts of the package:
|
|
|
3443
|
|
|
3444 @table @samp
|
|
|
3445 @item --enable-@var{feature}@r{[}=@var{parameter}@r{]}
|
|
|
3446 Configure the package to build and install an optional user-level
|
|
|
3447 facility called @var{feature}. This allows users to choose which
|
|
|
3448 optional features to include. Giving an optional @var{parameter} of
|
|
|
3449 @samp{no} should omit @var{feature}, if it is built by default.
|
|
|
3450
|
|
|
3451 No @samp{--enable} option should @strong{ever} cause one feature to
|
|
|
3452 replace another. No @samp{--enable} option should ever substitute one
|
|
|
3453 useful behavior for another useful behavior. The only proper use for
|
|
|
3454 @samp{--enable} is for questions of whether to build part of the program
|
|
|
3455 or exclude it.
|
|
|
3456
|
|
|
3457 @item --with-@var{package}
|
|
|
3458 @c @r{[}=@var{parameter}@r{]}
|
|
|
3459 The package @var{package} will be installed, so configure this package
|
|
|
3460 to work with @var{package}.
|
|
|
3461
|
|
|
3462 @c Giving an optional @var{parameter} of
|
|
|
3463 @c @samp{no} should omit @var{package}, if it is used by default.
|
|
|
3464
|
|
|
3465 Possible values of @var{package} include
|
|
|
3466 @samp{gnu-as} (or @samp{gas}), @samp{gnu-ld}, @samp{gnu-libc},
|
|
|
3467 @samp{gdb},
|
|
|
3468 @samp{x},
|
|
|
3469 and
|
|
|
3470 @samp{x-toolkit}.
|
|
|
3471
|
|
|
3472 Do not use a @samp{--with} option to specify the file name to use to
|
|
|
3473 find certain files. That is outside the scope of what @samp{--with}
|
|
|
3474 options are for.
|
|
|
3475 @end table
|
|
|
3476
|
|
|
3477 All @code{configure} scripts should accept all of these ``detail''
|
|
|
3478 options, whether or not they make any difference to the particular
|
|
|
3479 package at hand. In particular, they should accept any option that
|
|
|
3480 starts with @samp{--with-} or @samp{--enable-}. This is so users will
|
|
|
3481 be able to configure an entire GNU source tree at once with a single set
|
|
|
3482 of options.
|
|
|
3483
|
|
|
3484 You will note that the categories @samp{--with-} and @samp{--enable-}
|
|
|
3485 are narrow: they @strong{do not} provide a place for any sort of option
|
|
|
3486 you might think of. That is deliberate. We want to limit the possible
|
|
|
3487 configuration options in GNU software. We do not want GNU programs to
|
|
|
3488 have idiosyncratic configuration options.
|
|
|
3489
|
|
462
|
3490 Packages that perform part of the compilation process may support
|
|
|
3491 cross-compilation. In such a case, the host and target machines for the
|
|
|
3492 program may be different.
|
|
|
3493
|
|
|
3494 The @code{configure} script should normally treat the specified type of
|
|
|
3495 system as both the host and the target, thus producing a program which
|
|
|
3496 works for the same type of machine that it runs on.
|
|
|
3497
|
|
|
3498 To configure a cross-compiler, cross-assembler, or what have you, you
|
|
|
3499 should specify a target different from the host, using the configure
|
|
|
3500 option @samp{--target=@var{targettype}}. The syntax for
|
|
|
3501 @var{targettype} is the same as for the host type. So the command would
|
|
|
3502 look like this:
|
|
|
3503
|
|
|
3504 @example
|
|
|
3505 ./configure @var{hosttype} --target=@var{targettype}
|
|
|
3506 @end example
|
|
|
3507
|
|
|
3508 Programs for which cross-operation is not meaningful need not accept the
|
|
|
3509 @samp{--target} option, because configuring an entire operating system for
|
|
|
3510 cross-operation is not a meaningful operation.
|
|
428
|
3511
|
|
|
3512 Bootstrapping a cross-compiler requires compiling it on a machine other
|
|
|
3513 than the host it will run on. Compilation packages accept a
|
|
462
|
3514 configuration option @samp{--build=@var{buildtype}} for specifying the
|
|
|
3515 configuration on which you will compile them, but the configure script
|
|
|
3516 should normally guess the build machine type (using
|
|
|
3517 @file{config.guess}), so this option is probably not necessary. The
|
|
|
3518 host and target types normally default from the build type, so in
|
|
|
3519 bootstrapping a cross-compiler you must specify them both explicitly.
|
|
428
|
3520
|
|
|
3521 Some programs have ways of configuring themselves automatically. If
|
|
|
3522 your program is set up to do this, your @code{configure} script can simply
|
|
|
3523 ignore most of its arguments.
|
|
|
3524
|
|
|
3525 @comment The makefile standards are in a separate file that is also
|
|
|
3526 @comment included by make.texinfo. Done by roland@gnu.ai.mit.edu on 1/6/93.
|
|
|
3527 @comment For this document, turn chapters into sections, etc.
|
|
|
3528 @lowersections
|
|
|
3529 @include make-stds.texi
|
|
|
3530 @raisesections
|
|
|
3531
|
|
|
3532 @node Releases
|
|
|
3533 @section Making Releases
|
|
462
|
3534 @cindex packaging
|
|
428
|
3535
|
|
|
3536 Package the distribution of @code{Foo version 69.96} up in a gzipped tar
|
|
|
3537 file with the name @file{foo-69.96.tar.gz}. It should unpack into a
|
|
|
3538 subdirectory named @file{foo-69.96}.
|
|
|
3539
|
|
|
3540 Building and installing the program should never modify any of the files
|
|
|
3541 contained in the distribution. This means that all the files that form
|
|
|
3542 part of the program in any way must be classified into @dfn{source
|
|
|
3543 files} and @dfn{non-source files}. Source files are written by humans
|
|
|
3544 and never changed automatically; non-source files are produced from
|
|
|
3545 source files by programs under the control of the Makefile.
|
|
|
3546
|
|
462
|
3547 @cindex @file{README} file
|
|
428
|
3548 The distribution should contain a file named @file{README} which gives
|
|
|
3549 the name of the package, and a general description of what it does. It
|
|
|
3550 is also good to explain the purpose of each of the first-level
|
|
|
3551 subdirectories in the package, if there are any. The @file{README} file
|
|
|
3552 should either state the version number of the package, or refer to where
|
|
|
3553 in the package it can be found.
|
|
|
3554
|
|
|
3555 The @file{README} file should refer to the file @file{INSTALL}, which
|
|
|
3556 should contain an explanation of the installation procedure.
|
|
|
3557
|
|
|
3558 The @file{README} file should also refer to the file which contains the
|
|
|
3559 copying conditions. The GNU GPL, if used, should be in a file called
|
|
|
3560 @file{COPYING}. If the GNU LGPL is used, it should be in a file called
|
|
|
3561 @file{COPYING.LIB}.
|
|
|
3562
|
|
|
3563 Naturally, all the source files must be in the distribution. It is okay
|
|
|
3564 to include non-source files in the distribution, provided they are
|
|
|
3565 up-to-date and machine-independent, so that building the distribution
|
|
|
3566 normally will never modify them. We commonly include non-source files
|
|
|
3567 produced by Bison, @code{lex}, @TeX{}, and @code{makeinfo}; this helps avoid
|
|
|
3568 unnecessary dependencies between our distributions, so that users can
|
|
|
3569 install whichever packages they want to install.
|
|
|
3570
|
|
|
3571 Non-source files that might actually be modified by building and
|
|
|
3572 installing the program should @strong{never} be included in the
|
|
|
3573 distribution. So if you do distribute non-source files, always make
|
|
|
3574 sure they are up to date when you make a new distribution.
|
|
|
3575
|
|
|
3576 Make sure that the directory into which the distribution unpacks (as
|
|
|
3577 well as any subdirectories) are all world-writable (octal mode 777).
|
|
|
3578 This is so that old versions of @code{tar} which preserve the
|
|
|
3579 ownership and permissions of the files from the tar archive will be
|
|
|
3580 able to extract all the files even if the user is unprivileged.
|
|
|
3581
|
|
|
3582 Make sure that all the files in the distribution are world-readable.
|
|
|
3583
|
|
|
3584 Make sure that no file name in the distribution is more than 14
|
|
|
3585 characters long. Likewise, no file created by building the program
|
|
|
3586 should have a name longer than 14 characters. The reason for this is
|
|
|
3587 that some systems adhere to a foolish interpretation of the @sc{posix}
|
|
|
3588 standard, and refuse to open a longer name, rather than truncating as
|
|
|
3589 they did in the past.
|
|
|
3590
|
|
|
3591 Don't include any symbolic links in the distribution itself. If the tar
|
|
|
3592 file contains symbolic links, then people cannot even unpack it on
|
|
|
3593 systems that don't support symbolic links. Also, don't use multiple
|
|
|
3594 names for one file in different directories, because certain file
|
|
|
3595 systems cannot handle this and that prevents unpacking the
|
|
|
3596 distribution.
|
|
|
3597
|
|
|
3598 Try to make sure that all the file names will be unique on MS-DOS. A
|
|
|
3599 name on MS-DOS consists of up to 8 characters, optionally followed by a
|
|
|
3600 period and up to three characters. MS-DOS will truncate extra
|
|
|
3601 characters both before and after the period. Thus,
|
|
|
3602 @file{foobarhacker.c} and @file{foobarhacker.o} are not ambiguous; they
|
|
|
3603 are truncated to @file{foobarha.c} and @file{foobarha.o}, which are
|
|
|
3604 distinct.
|
|
|
3605
|
|
462
|
3606 @cindex @file{texinfo.tex}, in a distribution
|
|
428
|
3607 Include in your distribution a copy of the @file{texinfo.tex} you used
|
|
|
3608 to test print any @file{*.texinfo} or @file{*.texi} files.
|
|
|
3609
|
|
|
3610 Likewise, if your program uses small GNU software packages like regex,
|
|
|
3611 getopt, obstack, or termcap, include them in the distribution file.
|
|
|
3612 Leaving them out would make the distribution file a little smaller at
|
|
|
3613 the expense of possible inconvenience to a user who doesn't know what
|
|
|
3614 other files to get.
|
|
|
3615
|
|
|
3616 @node References
|
|
|
3617 @chapter References to Non-Free Software and Documentation
|
|
462
|
3618 @cindex references to non-free material
|
|
428
|
3619
|
|
|
3620 A GNU program should not recommend use of any non-free program. We
|
|
|
3621 can't stop some people from writing proprietary programs, or stop other
|
|
|
3622 people from using them. But we can and should avoid helping to
|
|
|
3623 advertise them to new customers.
|
|
|
3624
|
|
|
3625 Sometimes it is important to mention how to build your package on top of
|
|
|
3626 some non-free operating system or other non-free base package. In such
|
|
|
3627 cases, please mention the name of the non-free package or system in the
|
|
|
3628 briefest possible way. Don't include any references for where to find
|
|
|
3629 more information about the proprietary program. The goal should be that
|
|
|
3630 people already using the proprietary program will get the advice they
|
|
|
3631 need about how to use your free program, while people who don't already
|
|
|
3632 use the proprietary program will not see anything to encourage them to
|
|
|
3633 take an interest in it.
|
|
|
3634
|
|
|
3635 Likewise, a GNU package should not refer the user to any non-free
|
|
|
3636 documentation for free software. The need for free documentation to go
|
|
|
3637 with free software is now a major focus of the GNU project; to show that
|
|
|
3638 we are serious about the need for free documentation, we must not
|
|
|
3639 undermine our position by recommending use of documentation that isn't
|
|
|
3640 free.
|
|
|
3641
|
|
462
|
3642 @node Index
|
|
|
3643 @unnumbered Index
|
|
|
3644 @printindex cp
|
|
|
3645
|
|
428
|
3646 @contents
|
|
|
3647
|
|
|
3648 @bye
|
