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comparison lib-src/emacsserver.c @ 0:376386a54a3c r19-14

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Import from CVS: tag r19-14
author cvs
date Mon, 13 Aug 2007 08:45:50 +0200
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-1:000000000000 0:376386a54a3c
1 /* Communication subprocess for GNU Emacs acting as server.
2 Copyright (C) 1986, 1987, 1993 Free Software Foundation, Inc.
3
4 This file is part of GNU Emacs.
5
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; see the file COPYING. If not, write to
18 the Free the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21 /* Synched up with: FSF 19.28. */
22
23 /* The GNU Emacs edit server process is run as a subprocess of Emacs
24 under control of the file lisp/server.el.
25 This program accepts communication from client (program emacsclient.c)
26 and passes their commands (consisting of keyboard characters)
27 up to the Emacs which then executes them. */
28
29 #define NO_SHORTNAMES
30 #include <../src/config.h>
31 #undef read
32 #undef write
33 #undef open
34 #undef close
35 #undef signal
36
37 #if __STDC__ || defined(STDC_HEADERS)
38 # include <stdlib.h>
39 # include <unistd.h>
40 # include <fcntl.h> /* for creat() */
41 # include <string.h>
42 #else
43 extern int errno;
44 #endif
45
46 #if !defined(HAVE_SOCKETS) && !defined(HAVE_SYSVIPC)
47 #include <stdio.h>
48
49 void
50 main ()
51 {
52 fprintf (stderr, "Sorry, the Emacs server is supported only on systems\n");
53 fprintf (stderr, "with Berkeley sockets or System V IPC.\n");
54 exit (1);
55 }
56
57 #else /* HAVE_SOCKETS or HAVE_SYSVIPC */
58
59 #if ! defined (HAVE_SYSVIPC)
60 /* BSD code is very different from SYSV IPC code */
61
62 #include <sys/types.h>
63 #include <sys/file.h>
64 #include <sys/socket.h>
65 #include <sys/signal.h>
66 #include <sys/stat.h> /* Needed for chmod, at least on Linux */
67 #include <sys/un.h>
68 #include <stdio.h>
69 #include <errno.h>
70 #include "../src/sysproc.h" /* Needed for select */
71
72 void
73 main ()
74 {
75 char system_name[256];
76 int s, infd, fromlen;
77 struct sockaddr_un server, fromunix;
78 char *str, string[BUFSIZ], code[BUFSIZ];
79 FILE *infile;
80 FILE **openfiles;
81 int openfiles_size;
82
83 openfiles_size = 20;
84 openfiles = (FILE **) malloc (openfiles_size * sizeof (FILE *));
85 if (openfiles == 0)
86 abort ();
87
88 /*
89 * Open up an AF_UNIX socket in this person's home directory
90 */
91
92 if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
93 {
94 perror ("socket");
95 exit (1);
96 }
97 memset (&server, 0, sizeof (server));
98 server.sun_family = AF_UNIX;
99 #ifndef SERVER_HOME_DIR
100 gethostname (system_name, sizeof (system_name));
101 sprintf (server.sun_path, "/tmp/esrv%d-%s", (int) geteuid (), system_name);
102
103 if (unlink (server.sun_path) == -1 && errno != ENOENT)
104 {
105 perror ("unlink");
106 exit (1);
107 }
108 #else
109 {
110 char *homedir;
111
112 if ((homedir = getenv ("HOME")) == NULL)
113 {
114 fprintf (stderr,"No home directory\n");
115 exit (1);
116 }
117 sprintf (server.sun_path, "/tmp/esrv%d", geteuid ());
118 #if 0
119 strcpy (server.sun_path, homedir);
120 strcat (server.sun_path, "/.emacs_server");
121 #endif
122 /* Delete anyone else's old server. */
123 unlink (server.sun_path);
124 }
125 #endif /* SERVER_HOME_DIR */
126
127 {
128 int bindlen;
129
130 #ifdef HAVE_SOCKADDR_SUN_LEN
131 /* See W. R. Stevens "Advanced Programming in the Unix Environment"
132 p. 502 */
133 bindlen = (sizeof (server.sun_len) + sizeof (server.sun_family)
134 + strlen (server.sun_path) + 1);
135 server.sun_len = bindlen;
136 #else
137 bindlen = strlen (server.sun_path) + sizeof (server.sun_family);
138 #endif
139
140 if (bind (s, (struct sockaddr *) &server, bindlen) < 0)
141 {
142 perror ("bind");
143 exit (1);
144 }
145 }
146 /* Only this user can send commands to this Emacs. */
147 chmod (server.sun_path, 0600);
148 /*
149 * Now, just wait for everything to come in..
150 */
151 if (listen (s, 5) < 0)
152 {
153 perror ("listen");
154 exit (1);
155 }
156
157 /* Disable sigpipes in case luser kills client... */
158 signal (SIGPIPE, SIG_IGN);
159 for (;;)
160 {
161 int rmask = (1 << s) + 1;
162 if (select (s + 1, (fd_set *)&rmask, 0, 0, 0) < 0)
163 perror ("select");
164 if (rmask & (1 << s)) /* client sends list of filenames */
165 {
166 fromlen = sizeof (fromunix);
167 fromunix.sun_family = AF_UNIX;
168 infd = accept (s, (struct sockaddr *) &fromunix,
169 #ifdef HAVE_POSIX_ACCEPT
170 /* Posix dictates that this arg should be
171 a size_t *, but all known existing
172 implementations want an int *. */
173 (size_t *) &fromlen
174 #else
175 &fromlen
176 #endif
177 );
178 if (infd < 0)
179 {
180 if (errno == EMFILE || errno == ENFILE)
181 printf ("Too many clients.\n");
182 else
183 perror ("accept");
184 continue;
185 }
186
187 if (infd >= openfiles_size)
188 {
189 openfiles_size *= 2;
190 openfiles = (FILE **) realloc (openfiles,
191 openfiles_size * sizeof (FILE *));
192 if (openfiles == 0)
193 abort ();
194 }
195
196 infile = (FILE *) fdopen (infd, "r+"); /* open stream */
197 if (infile == NULL)
198 {
199 printf ("Too many clients.\n");
200 write (infd, "Too many clients.\n", 18);
201 close (infd); /* Prevent descriptor leak.. */
202 continue;
203 }
204 str = fgets (string, BUFSIZ, infile);
205 if (str == NULL)
206 {
207 perror ("fgets");
208 close (infd); /* Prevent descriptor leak.. */
209 continue;
210 }
211 openfiles[infd] = infile;
212 printf ("Client: %d %s", infd, string);
213 /* If what we read did not end in a newline,
214 it means there is more. Keep reading from the socket
215 and outputting to Emacs, until we get the newline. */
216 while (string[strlen (string) - 1] != '\n')
217 {
218 if (fgets (string, BUFSIZ, infile) == 0)
219 break;
220 printf ("%s", string);
221 }
222 fflush (stdout);
223 fflush (infile);
224 continue;
225 }
226 else if (rmask & 1) /* emacs sends codeword, fd, and string message */
227 {
228 /* Read command codeword and fd */
229 clearerr (stdin);
230 scanf ("%s %d%*c", code, &infd);
231
232 if (ferror (stdin) || feof (stdin))
233 {
234 fprintf (stderr, "server: error reading from standard input\n");
235 exit (1);
236 }
237
238 /* Transfer text from Emacs to the client, up to a newline. */
239 infile = openfiles[infd];
240 while (1)
241 {
242 if (fgets (string, BUFSIZ, stdin) == 0)
243 break;
244 fprintf (infile, "%s", string);
245 if (string[strlen (string) - 1] == '\n')
246 break;
247 }
248 fflush (infile);
249
250 /* If command is close, close connection to client. */
251 if (strncmp (code, "Close:", 6) == 0)
252 if (infd > 2)
253 {
254 fclose (infile);
255 close (infd);
256 }
257 continue;
258 }
259 }
260 }
261
262 #else /* This is the SYSV IPC section */
263
264 #include <sys/types.h>
265 #include <sys/signal.h>
266 #include <sys/ipc.h>
267 #include <sys/msg.h>
268 #include <setjmp.h>
269
270 jmp_buf msgenv;
271
272 static SIGTYPE
273 msgcatch (int arg)
274 {
275 longjmp (msgenv, 1);
276 }
277
278
279 /* "THIS has to be fixed. Remember, stderr may not exist...-rlk."
280 Incorrect. This program runs as an inferior of Emacs.
281 Its stderr always exists--rms. */
282 #include <stdio.h>
283
284 #if !__STDC__ && !defined(STDC_HEADERS)
285 #ifndef convex
286 char *getenv ();
287 #endif
288 #endif
289
290 void
291 main ()
292 {
293 int s, fromlen, ioproc;
294 #if 0
295 int infd;
296 #endif /* 0 */
297 key_t key;
298 struct msgbuf * msgp =
299 (struct msgbuf *) malloc (sizeof *msgp + BUFSIZ);
300 struct msqid_ds msg_st;
301 int p;
302 char *homedir;
303 char string[BUFSIZ];
304 #if 0
305 FILE *infile;
306 #endif /* 0 */
307
308 /*
309 * Create a message queue using ~/.emacs_server as the path for ftok
310 */
311 if ((homedir = getenv ("HOME")) == NULL)
312 {
313 fprintf (stderr,"No home directory\n");
314 exit (1);
315 }
316 strcpy (string, homedir);
317 strcat (string, "/.emacs_server");
318 creat (string, 0600);
319 key = ftok (string, 1); /* unlikely to be anyone else using it */
320 s = msgget (key, 0600 | IPC_CREAT);
321 if (s == -1)
322 {
323 perror ("msgget");
324 exit (1);
325 }
326
327 /* Fork so we can close connection even if parent dies */
328 p = fork ();
329 if (setjmp (msgenv))
330 {
331 msgctl (s, IPC_RMID, 0);
332 kill (p, SIGKILL);
333 exit (0);
334 }
335 signal (SIGTERM, msgcatch);
336 signal (SIGINT, msgcatch);
337 if (p > 0)
338 {
339 /* This is executed in the original process that did the fork above. */
340 /* Get pid of Emacs itself. */
341 p = getppid ();
342 setpgrp (); /* Gnu kills process group on exit */
343 while (1)
344 {
345 /* Is Emacs still alive? */
346 if (kill (p, 0) < 0)
347 {
348 msgctl (s, IPC_RMID, 0);
349 exit (0);
350 }
351 sleep (10);
352 }
353 }
354
355 /* This is executed in the child made by forking above.
356 Call it c1. Make another process, ioproc. */
357
358 ioproc = fork ();
359 if (ioproc == 0)
360 {
361 /* In process ioproc, wait for text from Emacs,
362 and send it to the process c1.
363 This way, c1 only has to wait for one source of input. */
364 while (fgets (msgp->mtext, BUFSIZ, stdin))
365 {
366 msgp->mtype = 1;
367 msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
368 }
369 exit (1);
370 }
371
372 /* In the process c1,
373 listen for messages from clients and pass them to Emacs. */
374 while (1)
375 {
376 if ((fromlen = msgrcv (s, msgp, BUFSIZ - 1, 1, 0)) < 0)
377 {
378 perror ("msgrcv");
379 exit (1);
380 }
381 else
382 {
383 msgctl (s, IPC_STAT, &msg_st);
384
385 /* Distinguish whether the message came from a client, or from
386 ioproc. */
387 if (msg_st.msg_lspid == ioproc)
388 {
389 char code[BUFSIZ];
390 int inproc;
391
392 /* Message from ioproc: tell a client we are done. */
393 msgp->mtext[strlen (msgp->mtext)-1] = 0;
394 sscanf (msgp->mtext, "%s %d", code, &inproc);
395 msgp->mtype = inproc;
396 msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
397 continue;
398 }
399
400 /* This is a request from a client: copy to stdout
401 so that Emacs will get it. Include msg_lspid
402 so server.el can tell us where to send the reply. */
403 strncpy (string, msgp->mtext, fromlen);
404 string[fromlen] = 0; /* make sure */
405 /* Newline is part of string.. */
406 printf ("Client: %d %s", (int) msg_st.msg_lspid, string);
407 fflush (stdout);
408 /* Now, wait for a wakeup */
409 }
410 }
411 }
412
413 #endif /* HAVE_SYSVIPC */
414
415 #endif /* HAVE_SOCKETS or HAVE_SYSVIPC */