*** empty log message ***
[emacs.git] / lib-src / emacsserver.c
blob3d099098436b3d558b27c62732e9bc1b967fa6ab
1 /* Communication subprocess for GNU Emacs acting as server.
2 Copyright (C) 1986, 1987, 1992, 1994, 1999 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
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.
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.
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 Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* The GNU Emacs edit server process is run as a subprocess of Emacs
23 under control of the file lisp/server.el.
24 This program accepts communication from client (program emacsclient.c)
25 and passes their commands (consisting of keyboard characters)
26 up to the Emacs which then executes them. */
28 #define NO_SHORTNAMES
30 #ifdef HAVE_CONFIG_H
31 #include <config.h>
32 #endif
34 #include <signal.h>
35 #undef signal
37 #if !defined (HAVE_SOCKETS) && !defined (HAVE_SYSVIPC)
38 #include <stdio.h>
40 int
41 main ()
43 fprintf (stderr, "Sorry, the Emacs server is supported only on systems\n");
44 fprintf (stderr, "with Berkeley sockets or System V IPC.\n");
45 exit (1);
48 #else /* HAVE_SOCKETS or HAVE_SYSVIPC */
50 void perror_1 ();
51 void fatal_error ();
53 #if defined (HAVE_SOCKETS) && ! defined (NO_SOCKETS_IN_FILE_SYSTEM)
54 /* BSD code is very different from SYSV IPC code */
56 #include <sys/types.h>
57 #include <sys/file.h>
58 #include <sys/socket.h>
59 #include <sys/un.h>
60 #include <stdio.h>
61 #include <errno.h>
62 #include <sys/stat.h>
64 #ifdef HAVE_UNISTD_H
65 #include <unistd.h>
66 #endif
68 #ifndef errno
69 extern int errno;
70 #endif
72 /* Copied from src/process.c */
73 #ifdef FD_SET
74 /* We could get this from param.h, but better not to depend on finding that.
75 And better not to risk that it might define other symbols used in this
76 file. */
77 #ifdef FD_SETSIZE
78 #define MAXDESC FD_SETSIZE
79 #else
80 #define MAXDESC 64
81 #endif
82 #define SELECT_TYPE fd_set
83 #else /* no FD_SET */
84 #define MAXDESC 32
85 #define SELECT_TYPE int
87 /* Define the macros to access a single-int bitmap of descriptors. */
88 #define FD_SET(n, p) (*(p) |= (1 << (n)))
89 #define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
90 #define FD_ISSET(n, p) (*(p) & (1 << (n)))
91 #define FD_ZERO(p) (*(p) = 0)
92 #endif /* no FD_SET */
94 /* This is the file name of the socket that we made. */
96 char *socket_name;
98 /* Name of this program. */
100 char *progname;
102 /* Handle fatal signals. */
104 /* This is the handler. */
106 SIGTYPE
107 delete_socket (sig)
108 int sig;
110 signal (sig, SIG_DFL);
111 unlink (socket_name);
112 kill (getpid (), sig);
115 /* Set up to handle all the signals. */
117 void
118 handle_signals ()
120 signal (SIGHUP, delete_socket);
121 signal (SIGINT, delete_socket);
122 signal (SIGQUIT, delete_socket);
123 signal (SIGILL, delete_socket);
124 signal (SIGTRAP, delete_socket);
125 #ifdef SIGABRT
126 signal (SIGABRT, delete_socket);
127 #endif
128 #ifdef SIGHWE
129 signal (SIGHWE, delete_socket);
130 #endif
131 #ifdef SIGPRE
132 signal (SIGPRE, delete_socket);
133 #endif
134 #ifdef SIGORE
135 signal (SIGORE, delete_socket);
136 #endif
137 #ifdef SIGUME
138 signal (SIGUME, delete_socket);
139 #endif
140 #ifdef SIGDLK
141 signal (SIGDLK, delete_socket);
142 #endif
143 #ifdef SIGCPULIM
144 signal (SIGCPULIM, delete_socket);
145 #endif
146 #ifdef SIGIOT
147 /* This is missing on some systems - OS/2, for example. */
148 signal (SIGIOT, delete_socket);
149 #endif
150 #ifdef SIGEMT
151 signal (SIGEMT, delete_socket);
152 #endif
153 signal (SIGFPE, delete_socket);
154 #ifdef SIGBUS
155 signal (SIGBUS, delete_socket);
156 #endif
157 signal (SIGSEGV, delete_socket);
158 #ifdef SIGSYS
159 signal (SIGSYS, delete_socket);
160 #endif
161 signal (SIGTERM, delete_socket);
162 #ifdef SIGXCPU
163 signal (SIGXCPU, delete_socket);
164 #endif
165 #ifdef SIGXFSZ
166 signal (SIGXFSZ, delete_socket);
167 #endif /* SIGXFSZ */
169 #ifdef AIX
170 /* 20 is SIGCHLD, 21 is SIGTTIN, 22 is SIGTTOU. */
171 signal (SIGXCPU, delete_socket);
172 #ifndef _I386
173 signal (SIGIOINT, delete_socket);
174 #endif
175 signal (SIGGRANT, delete_socket);
176 signal (SIGRETRACT, delete_socket);
177 signal (SIGSOUND, delete_socket);
178 signal (SIGMSG, delete_socket);
179 #endif /* AIX */
182 /* Print error message. `s1' is printf control string, `s2' is arg for it. */
183 void
184 error (s1, s2)
185 char *s1, *s2;
187 fprintf (stderr, "%s: ", progname);
188 fprintf (stderr, s1, s2);
189 fprintf (stderr, "\n");
192 /* Print error message and exit. */
193 void
194 fatal (s1, s2)
195 char *s1, *s2;
197 error (s1, s2);
198 exit (1);
201 /* Like malloc but get fatal error if memory is exhausted. */
203 long *
204 xmalloc (size)
205 unsigned int size;
207 long *result = (long *) malloc (size);
208 if (result == NULL)
209 fatal ("virtual memory exhausted", 0);
210 return result;
214 main (argc, argv)
215 int argc;
216 char **argv;
218 char *system_name;
219 int system_name_length;
220 int s, infd;
221 #ifdef SOCKLEN_TYPE
222 SOCKLEN_TYPE fromlen;
223 #else
224 size_t fromlen;
225 #endif
226 struct sockaddr_un server, fromunix;
227 #ifdef SERVER_HOME_DIR
228 char *homedir;
229 #endif
230 char *str, string[BUFSIZ], code[BUFSIZ];
231 FILE *infile;
232 FILE **openfiles;
233 int openfiles_size;
234 struct stat statbuf;
236 #ifndef convex
237 char *getenv ();
238 #endif
240 progname = argv[0];
242 openfiles_size = 20;
243 openfiles = (FILE **) malloc (openfiles_size * sizeof (FILE *));
244 if (openfiles == 0)
245 abort ();
248 * Open up an AF_UNIX socket in this person's home directory
251 if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
253 perror_1 ("socket");
254 exit (1);
256 server.sun_family = AF_UNIX;
258 system_name_length = 32;
259 while (1)
261 system_name = (char *) xmalloc (system_name_length + 1);
263 /* system_name must be null-terminated string. */
264 system_name[system_name_length] = '\0';
266 if (gethostname (system_name, system_name_length) == 0)
267 break;
269 free (system_name);
270 system_name_length *= 2;
273 #ifndef SERVER_HOME_DIR
274 sprintf (server.sun_path, "/tmp/esrv%d-%s", (int) geteuid (), system_name);
276 if (unlink (server.sun_path) == -1 && errno != ENOENT)
278 perror_1 ("unlink");
279 exit (1);
281 #else
282 if ((homedir = getenv ("HOME")) == NULL)
283 fatal_error ("No home directory\n");
285 strcpy (server.sun_path, homedir);
286 strcat (server.sun_path, "/.emacs-server-");
287 strcat (server.sun_path, system_name);
288 /* Delete anyone else's old server. */
289 unlink (server.sun_path);
290 #endif
292 /* Save the socket name so we can delete it. */
293 socket_name = (char *) xmalloc (strlen (server.sun_path) + 1);
294 strcpy (socket_name, server.sun_path);
296 handle_signals ();
298 if (bind (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2) < 0)
300 perror_1 ("bind");
301 exit (1);
303 /* Only this user can send commands to this Emacs. */
304 if (stat (server.sun_path, &statbuf) < 0)
306 perror_1 ("bind");
307 exit (1);
310 chmod (server.sun_path, statbuf.st_mode & 0600);
312 * Now, just wait for everything to come in..
314 if (listen (s, 5) < 0)
316 perror_1 ("listen");
317 exit (1);
320 /* Disable sigpipes in case luser kills client... */
321 signal (SIGPIPE, SIG_IGN);
322 for (;;)
324 SELECT_TYPE rmask;
325 FD_ZERO (&rmask);
326 FD_SET (0, &rmask);
327 FD_SET (s, &rmask);
328 if (select (s + 1, &rmask, 0, 0, 0) < 0)
329 perror_1 ("select");
330 if (FD_ISSET (s, &rmask)) /* client sends list of filenames */
332 fromlen = sizeof (fromunix);
333 fromunix.sun_family = AF_UNIX;
334 infd = accept (s, (struct sockaddr *) &fromunix, &fromlen);
335 if (infd < 0)
337 if (errno == EMFILE || errno == ENFILE)
338 fprintf (stderr, "Error: too many clients.\n");
339 else
340 perror_1 ("accept");
341 continue;
344 if (infd >= openfiles_size)
346 openfiles_size *= 2;
347 openfiles = (FILE **) realloc (openfiles,
348 openfiles_size * sizeof (FILE *));
349 if (openfiles == 0)
350 abort ();
353 infile = fdopen (infd, "r+"); /* open stream */
354 if (infile == NULL)
356 fprintf (stderr, "Error: too many clients.\n");
357 write (infd, "Too many clients.\n", 18);
358 close (infd); /* Prevent descriptor leak.. */
359 continue;
361 str = fgets (string, BUFSIZ, infile);
362 if (str == NULL)
364 perror_1 ("fgets");
365 close (infd); /* Prevent descriptor leak.. */
366 continue;
368 openfiles[infd] = infile;
369 printf ("Client: %d %s", infd, string);
370 /* If what we read did not end in a newline,
371 it means there is more. Keep reading from the socket
372 and outputting to Emacs, until we get the newline. */
373 while (string[strlen (string) - 1] != '\n')
375 if (fgets (string, BUFSIZ, infile) == 0)
376 break;
377 printf ("%s", string);
379 fflush (stdout);
380 fflush (infile);
381 continue;
383 else if (FD_ISSET (0, &rmask)) /* emacs sends codeword, fd, and string message */
385 /* Read command codeword and fd */
386 clearerr (stdin);
387 scanf ("%s %d%*c", code, &infd);
388 if (ferror (stdin) || feof (stdin))
389 fatal_error ("server: error reading from standard input\n");
391 /* Transfer text from Emacs to the client, up to a newline. */
392 infile = openfiles[infd];
393 rewind (infile);
394 while (1)
396 if (fgets (string, BUFSIZ, stdin) == 0)
397 break;
398 fprintf (infile, "%s", string);
399 if (string[strlen (string) - 1] == '\n')
400 break;
402 fflush (infile);
404 /* If command is close, close connection to client. */
405 if (strncmp (code, "Close:", 6) == 0)
406 if (infd > 2)
408 fclose (infile);
409 close (infd);
411 continue;
416 #else /* This is the SYSV IPC section */
418 #include <sys/types.h>
419 #include <sys/ipc.h>
420 #include <sys/msg.h>
421 #include <setjmp.h>
422 #include <errno.h>
423 #include <sys/utsname.h>
425 struct utsname system_name;
427 #ifndef errno
428 extern int errno;
429 #endif
431 jmp_buf msgenv;
433 SIGTYPE
434 msgcatch ()
436 longjmp (msgenv, 1);
440 /* "THIS has to be fixed. Remember, stderr may not exist...-rlk."
441 Incorrect. This program runs as an inferior of Emacs.
442 Its stderr always exists--rms. */
443 #include <stdio.h>
446 main ()
448 int s, infd, fromlen, ioproc;
449 key_t key;
450 struct msgbuf * msgp =
451 (struct msgbuf *) malloc (sizeof *msgp + BUFSIZ);
452 struct msqid_ds msg_st;
453 int p;
454 char *homedir, *getenv ();
455 char string[BUFSIZ];
456 FILE *infile;
459 * Create a message queue using ~/.emacs-server as the path for ftok
461 if ((homedir = getenv ("HOME")) == NULL)
462 fatal_error ("No home directory\n");
464 strcpy (string, homedir);
465 #ifndef HAVE_LONG_FILE_NAMES
466 /* If file names are short, we can't fit the host name. */
467 strcat (string, "/.emacs-server");
468 #else
469 strcat (string, "/.emacs-server-");
470 uname (&system_name);
471 strcat (string, system_name.nodename);
472 #endif
473 creat (string, 0600);
474 key = ftok (string, 1); /* unlikely to be anyone else using it */
475 s = msgget (key, 0600 | IPC_CREAT);
476 if (s == -1)
478 perror_1 ("msgget");
479 exit (1);
482 /* Fork so we can close connection even if parent dies */
483 p = fork ();
484 if (setjmp (msgenv))
486 msgctl (s, IPC_RMID, 0);
487 if (p > 0)
488 kill (p, SIGKILL);
489 exit (0);
491 signal (SIGTERM, msgcatch);
492 signal (SIGINT, msgcatch);
493 signal (SIGHUP, msgcatch);
494 if (p > 0)
496 /* This is executed in the original process that did the fork above. */
497 /* Get pid of Emacs itself. */
498 p = getppid ();
499 setpgrp (); /* Gnu kills process group on exit */
500 while (1)
502 /* Is Emacs still alive? */
503 if (kill (p, 0) < 0)
505 msgctl (s, IPC_RMID, 0);
506 exit (0);
508 sleep (10);
512 /* This is executed in the child made by forking above.
513 Call it c1. Make another process, ioproc. */
515 ioproc = fork ();
516 if (ioproc == 0)
518 /* In process ioproc, wait for text from Emacs,
519 and send it to the process c1.
520 This way, c1 only has to wait for one source of input. */
521 while (fgets (msgp->mtext, BUFSIZ, stdin))
523 msgp->mtype = 1;
524 msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
526 exit (1);
529 /* In the process c1,
530 listen for messages from clients and pass them to Emacs. */
531 while (1)
533 if ((fromlen = msgrcv (s, msgp, BUFSIZ - 1, 1, 0)) < 0)
535 #ifdef EINTR
536 if (errno == EINTR)
537 continue;
538 #endif
539 perror_1 ("msgrcv");
540 exit (1);
542 else
544 msgctl (s, IPC_STAT, &msg_st);
546 /* Distinguish whether the message came from a client, or from
547 ioproc. */
548 if (msg_st.msg_lspid == ioproc)
550 char code[BUFSIZ];
551 int inproc;
553 /* Message from ioproc: tell a client we are done. */
554 msgp->mtext[strlen (msgp->mtext)-1] = 0;
555 sscanf (msgp->mtext, "%s %d", code, &inproc);
556 msgp->mtype = inproc;
557 msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
558 continue;
561 /* This is a request from a client: copy to stdout
562 so that Emacs will get it. Include msg_lspid
563 so server.el can tell us where to send the reply. */
564 strncpy (string, msgp->mtext, fromlen);
565 string[fromlen] = 0; /* make sure */
566 /* Newline is part of string.. */
567 printf ("Client: %d %s", msg_st.msg_lspid, string);
568 fflush (stdout);
573 #endif /* HAVE_SYSVIPC */
576 /* This is like perror but puts `Error: ' at the beginning. */
578 void
579 perror_1 (string)
580 char *string;
582 char *copy = (char *) malloc (strlen (string) + 8);
583 if (copy == 0)
584 fatal_error ("Virtual memory exhausted");
586 strcpy (copy, "Error: ");
587 strcat (copy, string);
588 perror (copy);
591 void
592 fatal_error (string)
593 char *string;
595 fprintf (stderr, "%s", "Error: ");
596 fprintf (stderr, string);
597 exit (1);
599 #endif /* HAVE_SOCKETS or HAVE_SYSVIPC */