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1 @c -*-texinfo-*-
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2 @c This is part of the XEmacs Lisp Reference Manual.
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3 @c Copyright (C) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
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4 @c See the file lispref.texi for copying conditions.
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5 @setfilename ../../info/backups.info
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6 @node Backups and Auto-Saving, Buffers, Files, Top
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7 @chapter Backups and Auto-Saving
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8
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9 Backup files and auto-save files are two methods by which XEmacs tries
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10 to protect the user from the consequences of crashes or of the user's
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11 own errors. Auto-saving preserves the text from earlier in the current
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12 editing session; backup files preserve file contents prior to the
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13 current session.
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14
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15 @menu
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16 * Backup Files:: How backup files are made; how their names are chosen.
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17 * Auto-Saving:: How auto-save files are made; how their names are chosen.
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18 * Reverting:: @code{revert-buffer}, and how to customize what it does.
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19 @end menu
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20
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21 @node Backup Files
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22 @section Backup Files
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23 @cindex backup file
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24
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25 A @dfn{backup file} is a copy of the old contents of a file you are
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26 editing. XEmacs makes a backup file the first time you save a buffer
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27 into its visited file. Normally, this means that the backup file
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28 contains the contents of the file as it was before the current editing
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29 session. The contents of the backup file normally remain unchanged once
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30 it exists.
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31
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32 Backups are usually made by renaming the visited file to a new name.
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33 Optionally, you can specify that backup files should be made by copying
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34 the visited file. This choice makes a difference for files with
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35 multiple names; it also can affect whether the edited file remains owned
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36 by the original owner or becomes owned by the user editing it.
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37
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38 By default, XEmacs makes a single backup file for each file edited.
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39 You can alternatively request numbered backups; then each new backup
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40 file gets a new name. You can delete old numbered backups when you
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41 don't want them any more, or XEmacs can delete them automatically.
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42
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43 @menu
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44 * Making Backups:: How XEmacs makes backup files, and when.
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45 * Rename or Copy:: Two alternatives: renaming the old file or copying it.
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46 * Numbered Backups:: Keeping multiple backups for each source file.
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47 * Backup Names:: How backup file names are computed; customization.
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48 @end menu
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49
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50 @node Making Backups
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51 @subsection Making Backup Files
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52
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53 @defun backup-buffer
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54 This function makes a backup of the file visited by the current
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55 buffer, if appropriate. It is called by @code{save-buffer} before
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56 saving the buffer the first time.
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57 @end defun
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58
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59 @defvar buffer-backed-up
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60 This buffer-local variable indicates whether this buffer's file has
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61 been backed up on account of this buffer. If it is non-@code{nil}, then
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62 the backup file has been written. Otherwise, the file should be backed
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63 up when it is next saved (if backups are enabled). This is a
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64 permanent local; @code{kill-local-variables} does not alter it.
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65 @end defvar
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66
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67 @defopt make-backup-files
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68 This variable determines whether or not to make backup files. If it
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69 is non-@code{nil}, then XEmacs creates a backup of each file when it is
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70 saved for the first time---provided that @code{backup-inhibited}
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71 is @code{nil} (see below).
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72
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73 The following example shows how to change the @code{make-backup-files}
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74 variable only in the @file{RMAIL} buffer and not elsewhere. Setting it
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75 @code{nil} stops XEmacs from making backups of the @file{RMAIL} file,
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76 which may save disk space. (You would put this code in your
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77 @file{.emacs} file.)
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78
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79 @smallexample
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80 @group
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81 (add-hook 'rmail-mode-hook
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82 (function (lambda ()
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83 (make-local-variable
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84 'make-backup-files)
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85 (setq make-backup-files nil))))
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86 @end group
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87 @end smallexample
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88 @end defopt
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89
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90 @defvar backup-enable-predicate
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91 This variable's value is a function to be called on certain occasions to
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92 decide whether a file should have backup files. The function receives
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93 one argument, a file name to consider. If the function returns
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94 @code{nil}, backups are disabled for that file. Otherwise, the other
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95 variables in this section say whether and how to make backups.
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96
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97 The default value is this:
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98
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99 @example
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100 (lambda (name)
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101 (or (< (length name) 5)
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102 (not (string-equal "/tmp/"
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103 (substring name 0 5)))))
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104 @end example
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105 @end defvar
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106
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107 @defvar backup-inhibited
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108 If this variable is non-@code{nil}, backups are inhibited. It records
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109 the result of testing @code{backup-enable-predicate} on the visited file
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110 name. It can also coherently be used by other mechanisms that inhibit
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111 backups based on which file is visited. For example, VC sets this
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112 variable non-@code{nil} to prevent making backups for files managed
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113 with a version control system.
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114
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115 This is a permanent local, so that changing the major mode does not lose
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116 its value. Major modes should not set this variable---they should set
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117 @code{make-backup-files} instead.
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118 @end defvar
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119
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120 @node Rename or Copy
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121 @subsection Backup by Renaming or by Copying?
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122 @cindex backup files, how to make them
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123
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124 There are two ways that XEmacs can make a backup file:
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125
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126 @itemize @bullet
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127 @item
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128 XEmacs can rename the original file so that it becomes a backup file, and
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129 then write the buffer being saved into a new file. After this
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130 procedure, any other names (i.e., hard links) of the original file now
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131 refer to the backup file. The new file is owned by the user doing the
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132 editing, and its group is the default for new files written by the user
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133 in that directory.
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134
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135 @item
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136 XEmacs can copy the original file into a backup file, and then overwrite
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137 the original file with new contents. After this procedure, any other
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138 names (i.e., hard links) of the original file still refer to the current
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139 version of the file. The file's owner and group will be unchanged.
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140 @end itemize
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141
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142 The first method, renaming, is the default.
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143
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144 The variable @code{backup-by-copying}, if non-@code{nil}, says to use
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145 the second method, which is to copy the original file and overwrite it
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146 with the new buffer contents. The variable @code{file-precious-flag},
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147 if non-@code{nil}, also has this effect (as a sideline of its main
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148 significance). @xref{Saving Buffers}.
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149
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150 @defvar backup-by-copying
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151 If this variable is non-@code{nil}, XEmacs always makes backup files by
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152 copying.
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153 @end defvar
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154
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155 The following two variables, when non-@code{nil}, cause the second
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156 method to be used in certain special cases. They have no effect on the
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157 treatment of files that don't fall into the special cases.
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158
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159 @defvar backup-by-copying-when-linked
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160 If this variable is non-@code{nil}, XEmacs makes backups by copying for
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161 files with multiple names (hard links).
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162
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163 This variable is significant only if @code{backup-by-copying} is
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164 @code{nil}, since copying is always used when that variable is
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165 non-@code{nil}.
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166 @end defvar
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167
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168 @defvar backup-by-copying-when-mismatch
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169 If this variable is non-@code{nil}, XEmacs makes backups by copying in cases
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170 where renaming would change either the owner or the group of the file.
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171
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172 The value has no effect when renaming would not alter the owner or
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173 group of the file; that is, for files which are owned by the user and
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174 whose group matches the default for a new file created there by the
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175 user.
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176
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177 This variable is significant only if @code{backup-by-copying} is
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178 @code{nil}, since copying is always used when that variable is
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179 non-@code{nil}.
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180 @end defvar
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181
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182 @node Numbered Backups
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183 @subsection Making and Deleting Numbered Backup Files
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184
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185 If a file's name is @file{foo}, the names of its numbered backup
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186 versions are @file{foo.~@var{v}~}, for various integers @var{v}, like
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187 this: @file{foo.~1~}, @file{foo.~2~}, @file{foo.~3~}, @dots{},
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188 @file{foo.~259~}, and so on.
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189
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190 @defopt version-control
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191 This variable controls whether to make a single non-numbered backup
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192 file or multiple numbered backups.
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193
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194 @table @asis
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195 @item @code{nil}
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196 Make numbered backups if the visited file already has numbered backups;
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197 otherwise, do not.
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198
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199 @item @code{never}
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200 Do not make numbered backups.
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201
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202 @item @var{anything else}
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203 Make numbered backups.
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204 @end table
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205 @end defopt
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206
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207 The use of numbered backups ultimately leads to a large number of
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208 backup versions, which must then be deleted. XEmacs can do this
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209 automatically or it can ask the user whether to delete them.
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210
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211 @defopt kept-new-versions
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212 The value of this variable is the number of newest versions to keep
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213 when a new numbered backup is made. The newly made backup is included
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214 in the count. The default value is 2.
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215 @end defopt
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216
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217 @defopt kept-old-versions
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218 The value of this variable is the number of oldest versions to keep
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219 when a new numbered backup is made. The default value is 2.
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220 @end defopt
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221
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222 If there are backups numbered 1, 2, 3, 5, and 7, and both of these
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223 variables have the value 2, then the backups numbered 1 and 2 are kept
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224 as old versions and those numbered 5 and 7 are kept as new versions;
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225 backup version 3 is excess. The function @code{find-backup-file-name}
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226 (@pxref{Backup Names}) is responsible for determining which backup
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227 versions to delete, but does not delete them itself.
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228
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359
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229 @defopt delete-old-versions
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230 If this variable is non-@code{nil}, then saving a file deletes excess
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231 backup versions silently. Otherwise, it asks the user whether to delete
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232 them.
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233 @end defopt
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234
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235 @defopt dired-kept-versions
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236 This variable specifies how many of the newest backup versions to keep
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237 in the Dired command @kbd{.} (@code{dired-clean-directory}). That's the
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238 same thing @code{kept-new-versions} specifies when you make a new backup
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239 file. The default value is 2.
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240 @end defopt
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241
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242 @node Backup Names
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243 @subsection Naming Backup Files
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244
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245 The functions in this section are documented mainly because you can
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246 customize the naming conventions for backup files by redefining them.
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247 If you change one, you probably need to change the rest.
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248
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249 @defun backup-file-name-p filename
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250 This function returns a non-@code{nil} value if @var{filename} is a
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251 possible name for a backup file. A file with the name @var{filename}
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252 need not exist; the function just checks the name.
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253
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254 @smallexample
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255 @group
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256 (backup-file-name-p "foo")
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257 @result{} nil
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258 @end group
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259 @group
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260 (backup-file-name-p "foo~")
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261 @result{} 3
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262 @end group
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263 @end smallexample
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264
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265 The standard definition of this function is as follows:
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266
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267 @smallexample
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268 @group
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269 (defun backup-file-name-p (file)
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270 "Return non-nil if FILE is a backup file \
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271 name (numeric or not)..."
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272 (string-match "~$" file))
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273 @end group
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274 @end smallexample
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275
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276 @noindent
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277 Thus, the function returns a non-@code{nil} value if the file name ends
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278 with a @samp{~}. (We use a backslash to split the documentation
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279 string's first line into two lines in the text, but produce just one
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280 line in the string itself.)
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281
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282 This simple expression is placed in a separate function to make it easy
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283 to redefine for customization.
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284 @end defun
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285
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286 @defun make-backup-file-name filename
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287 This function returns a string that is the name to use for a
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288 non-numbered backup file for file @var{filename}. On Unix, this is just
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289 @var{filename} with a tilde appended.
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290
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291 The standard definition of this function is as follows:
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292
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293 @smallexample
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294 @group
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295 (defun make-backup-file-name (file)
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296 "Create the non-numeric backup file name for FILE.
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297 @dots{}"
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298 (concat file "~"))
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299 @end group
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300 @end smallexample
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301
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302 You can change the backup-file naming convention by redefining this
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303 function. The following example redefines @code{make-backup-file-name}
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304 to prepend a @samp{.} in addition to appending a tilde:
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305
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306 @smallexample
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307 @group
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308 (defun make-backup-file-name (filename)
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309 (concat "." filename "~"))
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310 @end group
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311
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312 @group
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313 (make-backup-file-name "backups.texi")
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314 @result{} ".backups.texi~"
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315 @end group
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316 @end smallexample
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317 @end defun
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318
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319 @defun find-backup-file-name filename
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320 This function computes the file name for a new backup file for
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321 @var{filename}. It may also propose certain existing backup files for
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322 deletion. @code{find-backup-file-name} returns a list whose @sc{car} is
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323 the name for the new backup file and whose @sc{cdr} is a list of backup
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324 files whose deletion is proposed.
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325
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326 Two variables, @code{kept-old-versions} and @code{kept-new-versions},
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327 determine which backup versions should be kept. This function keeps
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328 those versions by excluding them from the @sc{cdr} of the value.
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329 @xref{Numbered Backups}.
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330
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331 In this example, the value says that @file{~rms/foo.~5~} is the name
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332 to use for the new backup file, and @file{~rms/foo.~3~} is an ``excess''
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333 version that the caller should consider deleting now.
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334
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335 @smallexample
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336 @group
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337 (find-backup-file-name "~rms/foo")
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338 @result{} ("~rms/foo.~5~" "~rms/foo.~3~")
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339 @end group
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340 @end smallexample
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341 @end defun
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342
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343 @c Emacs 19 feature
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344 @defun file-newest-backup filename
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345 This function returns the name of the most recent backup file for
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346 @var{filename}, or @code{nil} if that file has no backup files.
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347
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348 Some file comparison commands use this function so that they can
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349 automatically compare a file with its most recent backup.
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444
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350 @end defun
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351
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352 @node Auto-Saving
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353 @section Auto-Saving
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354 @cindex auto-saving
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355
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356 XEmacs periodically saves all files that you are visiting; this is
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357 called @dfn{auto-saving}. Auto-saving prevents you from losing more
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358 than a limited amount of work if the system crashes. By default,
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359 auto-saves happen every 300 keystrokes, or after around 30 seconds of
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360 idle time. @xref{Auto Save, Auto-Save, Auto-Saving: Protection Against
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361 Disasters, xemacs, The XEmacs User's Manual}, for information on
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446
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362 auto-save for users. Here we describe the functions used to implement
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363 auto-saving and the variables that control them.
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0
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364
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365 @defvar buffer-auto-save-file-name
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366 This buffer-local variable is the name of the file used for
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367 auto-saving the current buffer. It is @code{nil} if the buffer
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368 should not be auto-saved.
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369
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370 @example
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371 @group
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372 buffer-auto-save-file-name
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373 => "/xcssun/users/rms/lewis/#files.texi#"
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374 @end group
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375 @end example
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376 @end defvar
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377
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378 @deffn Command auto-save-mode arg
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379 When used interactively without an argument, this command is a toggle
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380 switch: it turns on auto-saving of the current buffer if it is off, and
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381 vice-versa. With an argument @var{arg}, the command turns auto-saving
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382 on if the value of @var{arg} is @code{t}, a nonempty list, or a positive
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383 integer. Otherwise, it turns auto-saving off.
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384 @end deffn
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385
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386 @defun auto-save-file-name-p filename
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387 This function returns a non-@code{nil} value if @var{filename} is a
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388 string that could be the name of an auto-save file. It works based on
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389 knowledge of the naming convention for auto-save files: a name that
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390 begins and ends with hash marks (@samp{#}) is a possible auto-save file
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391 name. The argument @var{filename} should not contain a directory part.
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392
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393 @example
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394 @group
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395 (make-auto-save-file-name)
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396 @result{} "/xcssun/users/rms/lewis/#files.texi#"
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397 @end group
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398 @group
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399 (auto-save-file-name-p "#files.texi#")
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400 @result{} 0
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401 @end group
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402 @group
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403 (auto-save-file-name-p "files.texi")
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404 @result{} nil
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405 @end group
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406 @end example
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407
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408 The standard definition of this function is as follows:
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409
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410 @example
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411 @group
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412 (defun auto-save-file-name-p (filename)
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413 "Return non-nil if FILENAME can be yielded by..."
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414 (string-match "^#.*#$" filename))
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415 @end group
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416 @end example
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417
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418 This function exists so that you can customize it if you wish to
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419 change the naming convention for auto-save files. If you redefine it,
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420 be sure to redefine the function @code{make-auto-save-file-name}
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421 correspondingly.
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422 @end defun
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423
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444
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424 @defun make-auto-save-file-name &optional filename
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0
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425 This function returns the file name to use for auto-saving the current
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426 buffer. This is just the file name with hash marks (@samp{#}) appended
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427 and prepended to it. This function does not look at the variable
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428 @code{auto-save-visited-file-name} (described below); you should check
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429 that before calling this function.
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430
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431 @example
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432 @group
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433 (make-auto-save-file-name)
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434 @result{} "/xcssun/users/rms/lewis/#backup.texi#"
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435 @end group
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436 @end example
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437
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438 The standard definition of this function is as follows:
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439
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440 @example
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441 @group
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442 (defun make-auto-save-file-name ()
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443 "Return file name to use for auto-saves \
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|
444 of current buffer.
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445 @dots{}"
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446 (if buffer-file-name
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447 @end group
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448 @group
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449 (concat
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450 (file-name-directory buffer-file-name)
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451 "#"
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|
452 (file-name-nondirectory buffer-file-name)
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453 "#")
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|
454 (expand-file-name
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455 (concat "#%" (buffer-name) "#"))))
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456 @end group
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|
457 @end example
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458
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459 This exists as a separate function so that you can redefine it to
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460 customize the naming convention for auto-save files. Be sure to
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461 change @code{auto-save-file-name-p} in a corresponding way.
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|
462 @end defun
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463
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464 @defvar auto-save-visited-file-name
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465 If this variable is non-@code{nil}, XEmacs auto-saves buffers in
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466 the files they are visiting. That is, the auto-save is done in the same
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467 file that you are editing. Normally, this variable is @code{nil}, so
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468 auto-save files have distinct names that are created by
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469 @code{make-auto-save-file-name}.
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470
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471 When you change the value of this variable, the value does not take
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472 effect until the next time auto-save mode is reenabled in any given
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473 buffer. If auto-save mode is already enabled, auto-saves continue to go
|
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|
474 in the same file name until @code{auto-save-mode} is called again.
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|
475 @end defvar
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476
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|
477 @defun recent-auto-save-p
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|
478 This function returns @code{t} if the current buffer has been
|
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479 auto-saved since the last time it was read in or saved.
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|
|
480 @end defun
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481
|
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|
482 @defun set-buffer-auto-saved
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483 This function marks the current buffer as auto-saved. The buffer will
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484 not be auto-saved again until the buffer text is changed again. The
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485 function returns @code{nil}.
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|
486 @end defun
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487
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488 @defopt auto-save-interval
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489 The value of this variable is the number of characters that XEmacs
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|
490 reads from the keyboard between auto-saves. Each time this many more
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|
491 characters are read, auto-saving is done for all buffers in which it is
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492 enabled.
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|
493 @end defopt
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494
|
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|
495 @defopt auto-save-timeout
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496 The value of this variable is the number of seconds of idle time that
|
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|
497 should cause auto-saving. Each time the user pauses for this long,
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|
498 XEmacs auto-saves any buffers that need it. (Actually, the specified
|
|
|
499 timeout is multiplied by a factor depending on the size of the current
|
|
|
500 buffer.)
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|
501 @end defopt
|
|
|
502
|
|
|
503 @defvar auto-save-hook
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|
|
504 This normal hook is run whenever an auto-save is about to happen.
|
|
|
505 @end defvar
|
|
|
506
|
|
|
507 @defopt auto-save-default
|
|
|
508 If this variable is non-@code{nil}, buffers that are visiting files
|
|
|
509 have auto-saving enabled by default. Otherwise, they do not.
|
|
|
510 @end defopt
|
|
|
511
|
|
|
512 @deffn Command do-auto-save &optional no-message current-only
|
|
|
513 This function auto-saves all buffers that need to be auto-saved. It
|
|
|
514 saves all buffers for which auto-saving is enabled and that have been
|
|
|
515 changed since the previous auto-save.
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|
|
516
|
|
|
517 Normally, if any buffers are auto-saved, a message that says
|
|
|
518 @samp{Auto-saving...} is displayed in the echo area while auto-saving is
|
|
|
519 going on. However, if @var{no-message} is non-@code{nil}, the message
|
|
|
520 is inhibited.
|
|
|
521
|
|
|
522 If @var{current-only} is non-@code{nil}, only the current buffer
|
|
|
523 is auto-saved.
|
|
|
524 @end deffn
|
|
|
525
|
|
|
526 @defun delete-auto-save-file-if-necessary
|
|
|
527 This function deletes the current buffer's auto-save file if
|
|
|
528 @code{delete-auto-save-files} is non-@code{nil}. It is called every
|
|
|
529 time a buffer is saved.
|
|
|
530 @end defun
|
|
|
531
|
|
|
532 @defvar delete-auto-save-files
|
|
|
533 This variable is used by the function
|
|
|
534 @code{delete-auto-save-file-if-necessary}. If it is non-@code{nil},
|
|
|
535 Emacs deletes auto-save files when a true save is done (in the visited
|
|
|
536 file). This saves disk space and unclutters your directory.
|
|
|
537 @end defvar
|
|
|
538
|
|
|
539 @defun rename-auto-save-file
|
|
|
540 This function adjusts the current buffer's auto-save file name if the
|
|
|
541 visited file name has changed. It also renames an existing auto-save
|
|
|
542 file. If the visited file name has not changed, this function does
|
|
|
543 nothing.
|
|
|
544 @end defun
|
|
|
545
|
|
|
546 @defvar buffer-saved-size
|
|
|
547 The value of this buffer-local variable is the length of the current
|
|
|
548 buffer as of the last time it was read in, saved, or auto-saved. This is
|
|
|
549 used to detect a substantial decrease in size, and turn off auto-saving
|
|
|
550 in response.
|
|
|
551
|
|
|
552 If it is -1, that means auto-saving is temporarily shut off in this
|
|
|
553 buffer due to a substantial deletion. Explicitly saving the buffer
|
|
|
554 stores a positive value in this variable, thus reenabling auto-saving.
|
|
|
555 Turning auto-save mode off or on also alters this variable.
|
|
|
556 @end defvar
|
|
|
557
|
|
|
558 @defvar auto-save-list-file-name
|
|
|
559 This variable (if non-@code{nil}) specifies a file for recording the
|
|
|
560 names of all the auto-save files. Each time XEmacs does auto-saving, it
|
|
|
561 writes two lines into this file for each buffer that has auto-saving
|
|
|
562 enabled. The first line gives the name of the visited file (it's empty
|
|
|
563 if the buffer has none), and the second gives the name of the auto-save
|
|
|
564 file.
|
|
|
565
|
|
|
566 If XEmacs exits normally, it deletes this file. If XEmacs crashes, you
|
|
|
567 can look in the file to find all the auto-save files that might contain
|
|
|
568 work that was otherwise lost. The @code{recover-session} command uses
|
|
|
569 these files.
|
|
|
570
|
|
|
571 The default name for this file is in your home directory and starts with
|
|
|
572 @samp{.saves-}. It also contains the XEmacs process @sc{id} and the host
|
|
|
573 name.
|
|
|
574 @end defvar
|
|
|
575
|
|
|
576 @node Reverting
|
|
|
577 @section Reverting
|
|
|
578
|
|
|
579 If you have made extensive changes to a file and then change your mind
|
|
|
580 about them, you can get rid of them by reading in the previous version
|
|
|
581 of the file with the @code{revert-buffer} command. @xref{Reverting, ,
|
|
1710
|
582 Reverting a Buffer, xemacs, The XEmacs User's Manual}.
|
|
0
|
583
|
|
444
|
584 @deffn Command revert-buffer &optional check-auto-save noconfirm preserve-modes
|
|
0
|
585 This command replaces the buffer text with the text of the visited
|
|
|
586 file on disk. This action undoes all changes since the file was visited
|
|
|
587 or saved.
|
|
|
588
|
|
|
589 If the argument @var{check-auto-save} is non-@code{nil}, and the
|
|
|
590 latest auto-save file is more recent than the visited file,
|
|
|
591 @code{revert-buffer} asks the user whether to use that instead.
|
|
|
592 Otherwise, it always uses the text of the visited file itself.
|
|
|
593 Interactively, @var{check-auto-save} is set if there is a numeric prefix
|
|
|
594 argument.
|
|
|
595
|
|
|
596 Normally, @code{revert-buffer} asks for confirmation before it changes
|
|
|
597 the buffer; but if the argument @var{noconfirm} is non-@code{nil},
|
|
|
598 @code{revert-buffer} does not ask for confirmation.
|
|
|
599
|
|
444
|
600 Optional third argument @var{preserve-modes} non-@code{nil} means don't
|
|
|
601 alter the files modes. Normally we reinitialize them using
|
|
|
602 @code{normal-mode}.
|
|
|
603
|
|
0
|
604 Reverting tries to preserve marker positions in the buffer by using the
|
|
|
605 replacement feature of @code{insert-file-contents}. If the buffer
|
|
|
606 contents and the file contents are identical before the revert
|
|
|
607 operation, reverting preserves all the markers. If they are not
|
|
|
608 identical, reverting does change the buffer; then it preserves the
|
|
|
609 markers in the unchanged text (if any) at the beginning and end of the
|
|
|
610 buffer. Preserving any additional markers would be problematical.
|
|
|
611 @end deffn
|
|
|
612
|
|
|
613 You can customize how @code{revert-buffer} does its work by setting
|
|
|
614 these variables---typically, as buffer-local variables.
|
|
|
615
|
|
|
616 @defvar revert-buffer-function
|
|
|
617 The value of this variable is the function to use to revert this buffer.
|
|
|
618 If non-@code{nil}, it is called as a function with no arguments to do
|
|
|
619 the work of reverting. If the value is @code{nil}, reverting works the
|
|
|
620 usual way.
|
|
|
621
|
|
|
622 Modes such as Dired mode, in which the text being edited does not
|
|
|
623 consist of a file's contents but can be regenerated in some other
|
|
|
624 fashion, give this variable a buffer-local value that is a function to
|
|
|
625 regenerate the contents.
|
|
|
626 @end defvar
|
|
|
627
|
|
|
628 @defvar revert-buffer-insert-file-contents-function
|
|
|
629 The value of this variable, if non-@code{nil}, is the function to use to
|
|
|
630 insert the updated contents when reverting this buffer. The function
|
|
|
631 receives two arguments: first the file name to use; second, @code{t} if
|
|
|
632 the user has asked to read the auto-save file.
|
|
|
633 @end defvar
|
|
|
634
|
|
|
635 @defvar before-revert-hook
|
|
|
636 This normal hook is run by @code{revert-buffer} before actually
|
|
|
637 inserting the modified contents---but only if
|
|
|
638 @code{revert-buffer-function} is @code{nil}.
|
|
|
639
|
|
|
640 Font Lock mode uses this hook to record that the buffer contents are no
|
|
|
641 longer fontified.
|
|
|
642 @end defvar
|
|
|
643
|
|
|
644 @defvar after-revert-hook
|
|
|
645 This normal hook is run by @code{revert-buffer} after actually inserting
|
|
|
646 the modified contents---but only if @code{revert-buffer-function} is
|
|
|
647 @code{nil}.
|
|
|
648
|
|
|
649 Font Lock mode uses this hook to recompute the fonts for the updated
|
|
|
650 buffer contents.
|
|
|
651 @end defvar
|
|
|
652
|
