1 /* Communication subprocess for GNU Emacs acting as server.
2 Copyright (C) 1986, 1987, 1992, 1994 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)
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* The GNU Emacs edit server process is run as a subprocess of Emacs
22 under control of the file lisp/server.el.
23 This program accepts communication from client (program emacsclient.c)
24 and passes their commands (consisting of keyboard characters)
25 up to the Emacs which then executes them. */
28 #include <../src/config.h>
35 #if !defined (HAVE_SOCKETS) && !defined (HAVE_SYSVIPC)
40 fprintf (stderr
, "Sorry, the Emacs server is supported only on systems\n");
41 fprintf (stderr
, "with Berkeley sockets or System V IPC.\n");
45 #else /* HAVE_SOCKETS or HAVE_SYSVIPC */
47 #if defined (HAVE_SOCKETS) && ! defined (NO_SOCKETS_IN_FILE_SYSTEM)
48 /* BSD code is very different from SYSV IPC code */
50 #include <sys/types.h>
52 #include <sys/socket.h>
53 #include <sys/signal.h>
60 /* Copied from src/process.c */
62 /* We could get this from param.h, but better not to depend on finding that.
63 And better not to risk that it might define other symbols used in this
66 #define MAXDESC FD_SETSIZE
70 #define SELECT_TYPE fd_set
73 #define SELECT_TYPE int
75 /* Define the macros to access a single-int bitmap of descriptors. */
76 #define FD_SET(n, p) (*(p) |= (1 << (n)))
77 #define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
78 #define FD_ISSET(n, p) (*(p) & (1 << (n)))
79 #define FD_ZERO(p) (*(p) = 0)
80 #endif /* no FD_SET */
86 struct sockaddr_un server
, fromunix
;
88 char *str
, string
[BUFSIZ
], code
[BUFSIZ
];
98 openfiles
= (FILE **) malloc (openfiles_size
* sizeof (FILE *));
103 * Open up an AF_UNIX socket in this person's home directory
106 if ((s
= socket (AF_UNIX
, SOCK_STREAM
, 0)) < 0)
111 server
.sun_family
= AF_UNIX
;
112 #ifndef SERVER_HOME_DIR
113 gethostname (system_name
, sizeof (system_name
));
114 sprintf (server
.sun_path
, "/tmp/esrv%d-%s", geteuid (), system_name
);
116 if (unlink (server
.sun_path
) == -1 && errno
!= ENOENT
)
122 if ((homedir
= getenv ("HOME")) == NULL
)
123 fatal_error ("No home directory\n");
125 strcpy (server
.sun_path
, homedir
);
126 strcat (server
.sun_path
, "/.emacs-server-");
127 gethostname (system_name
, sizeof (system_name
));
128 strcat (server
.sun_path
, system_name
);
129 /* Delete anyone else's old server. */
130 unlink (server
.sun_path
);
133 if (bind (s
, (struct sockaddr
*) &server
, strlen (server
.sun_path
) + 2) < 0)
138 /* Only this user can send commands to this Emacs. */
139 chmod (server
.sun_path
, 0600);
141 * Now, just wait for everything to come in..
143 if (listen (s
, 5) < 0)
149 /* Disable sigpipes in case luser kills client... */
150 signal (SIGPIPE
, SIG_IGN
);
157 if (select (s
+ 1, &rmask
, 0, 0, 0) < 0)
159 if (FD_ISSET (s
, &rmask
)) /* client sends list of filenames */
161 fromlen
= sizeof (fromunix
);
162 fromunix
.sun_family
= AF_UNIX
;
163 infd
= accept (s
, (struct sockaddr
*) &fromunix
, &fromlen
);
166 if (errno
== EMFILE
|| errno
== ENFILE
)
167 fprintf (stderr
, "Error: too many clients.\n");
173 if (infd
>= openfiles_size
)
176 openfiles
= (FILE **) realloc (openfiles
,
177 openfiles_size
* sizeof (FILE *));
182 infile
= fdopen (infd
, "r+"); /* open stream */
185 fprintf (stderr
, "Error: too many clients.\n");
186 write (infd
, "Too many clients.\n", 18);
187 close (infd
); /* Prevent descriptor leak.. */
190 str
= fgets (string
, BUFSIZ
, infile
);
194 close (infd
); /* Prevent descriptor leak.. */
197 openfiles
[infd
] = infile
;
198 printf ("Client: %d %s", infd
, string
);
199 /* If what we read did not end in a newline,
200 it means there is more. Keep reading from the socket
201 and outputting to Emacs, until we get the newline. */
202 while (string
[strlen (string
) - 1] != '\n')
204 if (fgets (string
, BUFSIZ
, infile
) == 0)
206 printf ("%s", string
);
212 else if (FD_ISSET (0, &rmask
)) /* emacs sends codeword, fd, and string message */
214 /* Read command codeword and fd */
216 scanf ("%s %d%*c", code
, &infd
);
217 if (ferror (stdin
) || feof (stdin
))
218 fatal_error ("server: error reading from standard input\n");
220 /* Transfer text from Emacs to the client, up to a newline. */
221 infile
= openfiles
[infd
];
224 if (fgets (string
, BUFSIZ
, stdin
) == 0)
226 fprintf (infile
, "%s", string
);
227 if (string
[strlen (string
) - 1] == '\n')
232 /* If command is close, close connection to client. */
233 if (strncmp (code
, "Close:", 6) == 0)
244 #else /* This is the SYSV IPC section */
246 #include <sys/types.h>
247 #include <sys/signal.h>
252 #include <sys/utsname.h>
254 struct utsname system_name
;
269 /* "THIS has to be fixed. Remember, stderr may not exist...-rlk."
270 Incorrect. This program runs as an inferior of Emacs.
271 Its stderr always exists--rms. */
276 int s
, infd
, fromlen
, ioproc
;
278 struct msgbuf
* msgp
=
279 (struct msgbuf
*) malloc (sizeof *msgp
+ BUFSIZ
);
280 struct msqid_ds msg_st
;
282 char *homedir
, *getenv ();
287 * Create a message queue using ~/.emacs-server as the path for ftok
289 if ((homedir
= getenv ("HOME")) == NULL
)
290 fatal_error ("No home directory\n");
292 strcpy (string
, homedir
);
293 #ifndef HAVE_LONG_FILE_NAMES
294 /* If file names are short, we can't fit the host name. */
295 strcat (string
, "/.emacs-server");
297 strcat (string
, "/.emacs-server-");
298 uname (&system_name
);
299 strcat (string
, system_name
.nodename
);
301 creat (string
, 0600);
302 key
= ftok (string
, 1); /* unlikely to be anyone else using it */
303 s
= msgget (key
, 0600 | IPC_CREAT
);
310 /* Fork so we can close connection even if parent dies */
314 msgctl (s
, IPC_RMID
, 0);
319 signal (SIGTERM
, msgcatch
);
320 signal (SIGINT
, msgcatch
);
321 signal (SIGHUP
, msgcatch
);
324 /* This is executed in the original process that did the fork above. */
325 /* Get pid of Emacs itself. */
327 setpgrp (); /* Gnu kills process group on exit */
330 /* Is Emacs still alive? */
333 msgctl (s
, IPC_RMID
, 0);
340 /* This is executed in the child made by forking above.
341 Call it c1. Make another process, ioproc. */
346 /* In process ioproc, wait for text from Emacs,
347 and send it to the process c1.
348 This way, c1 only has to wait for one source of input. */
349 while (fgets (msgp
->mtext
, BUFSIZ
, stdin
))
352 msgsnd (s
, msgp
, strlen (msgp
->mtext
) + 1, 0);
357 /* In the process c1,
358 listen for messages from clients and pass them to Emacs. */
361 if ((fromlen
= msgrcv (s
, msgp
, BUFSIZ
- 1, 1, 0)) < 0)
372 msgctl (s
, IPC_STAT
, &msg_st
);
374 /* Distinguish whether the message came from a client, or from
376 if (msg_st
.msg_lspid
== ioproc
)
381 /* Message from ioproc: tell a client we are done. */
382 msgp
->mtext
[strlen (msgp
->mtext
)-1] = 0;
383 sscanf (msgp
->mtext
, "%s %d", code
, &inproc
);
384 msgp
->mtype
= inproc
;
385 msgsnd (s
, msgp
, strlen (msgp
->mtext
) + 1, 0);
389 /* This is a request from a client: copy to stdout
390 so that Emacs will get it. Include msg_lspid
391 so server.el can tell us where to send the reply. */
392 strncpy (string
, msgp
->mtext
, fromlen
);
393 string
[fromlen
] = 0; /* make sure */
394 /* Newline is part of string.. */
395 printf ("Client: %d %s", msg_st
.msg_lspid
, string
);
401 #endif /* HAVE_SYSVIPC */
403 #endif /* HAVE_SOCKETS or HAVE_SYSVIPC */
405 /* This is like perror but puts `Error: ' at the beginning. */
410 char *copy
= (char *) malloc (strlen (string
) + 8);
412 fatal_error ("Virtual memory exhausted");
414 strcpy (copy
, "Error: ");
415 strcat (copy
, string
);
422 fprintf (stderr
, "%s", "Error: ");
423 fprintf (stderr
, string
);