1 /* Communication subprocess for GNU Emacs acting as server.
2 Copyright (C) 1986, 1987, 1992 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>
36 #if !defined(HAVE_SOCKETS) && !defined(HAVE_SYSVIPC)
41 fprintf (stderr
, "Sorry, the Emacs server is supported only on systems\n");
42 fprintf (stderr
, "with Berkeley sockets or System V IPC.\n");
46 #else /* HAVE_SOCKETS or HAVE_SYSVIPC */
48 #if ! defined (HAVE_SYSVIPC)
49 /* BSD code is very different from SYSV IPC code */
51 #include <sys/types.h>
53 #include <sys/socket.h>
54 #include <sys/signal.h>
61 /* Copied from src/process.c */
63 /* We could get this from param.h, but better not to depend on finding that.
64 And better not to risk that it might define other symbols used in this
67 #define MAXDESC FD_SETSIZE
71 #define SELECT_TYPE fd_set
74 #define SELECT_TYPE int
76 /* Define the macros to access a single-int bitmap of descriptors. */
77 #define FD_SET(n, p) (*(p) |= (1 << (n)))
78 #define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
79 #define FD_ISSET(n, p) (*(p) & (1 << (n)))
80 #define FD_ZERO(p) (*(p) = 0)
81 #endif /* no FD_SET */
87 struct sockaddr_un server
, fromunix
;
89 char *str
, string
[BUFSIZ
], code
[BUFSIZ
];
99 openfiles
= (FILE **) malloc (openfiles_size
* sizeof (FILE *));
104 * Open up an AF_UNIX socket in this person's home directory
107 if ((s
= socket (AF_UNIX
, SOCK_STREAM
, 0)) < 0)
112 server
.sun_family
= AF_UNIX
;
113 #ifndef SERVER_HOME_DIR
114 gethostname (system_name
, sizeof (system_name
));
115 sprintf (server
.sun_path
, "/tmp/esrv%d-%s", geteuid (), system_name
);
117 if (unlink (server
.sun_path
) == -1 && errno
!= ENOENT
)
123 if ((homedir
= getenv ("HOME")) == NULL
)
125 fprintf (stderr
,"No home directory\n");
128 strcpy (server
.sun_path
, homedir
);
129 strcat (server
.sun_path
, "/.emacs_server");
130 /* Delete anyone else's old server. */
131 unlink (server
.sun_path
);
134 if (bind (s
, (struct sockaddr
*) &server
, strlen (server
.sun_path
) + 2) < 0)
139 /* Only this user can send commands to this Emacs. */
140 chmod (server
.sun_path
, 0600);
142 * Now, just wait for everything to come in..
144 if (listen (s
, 5) < 0)
150 /* Disable sigpipes in case luser kills client... */
151 signal (SIGPIPE
, SIG_IGN
);
158 if (select (s
+ 1, &rmask
, 0, 0, 0) < 0)
160 if (FD_ISSET (rmask
, s
)) /* client sends list of filenames */
162 fromlen
= sizeof (fromunix
);
163 fromunix
.sun_family
= AF_UNIX
;
164 infd
= accept (s
, (struct sockaddr
*) &fromunix
, &fromlen
);
167 if (errno
== EMFILE
|| errno
== ENFILE
)
168 printf ("Too many clients.\n");
174 if (infd
>= openfiles_size
)
177 openfiles
= (FILE **) realloc (openfiles
,
178 openfiles_size
* sizeof (FILE *));
183 infile
= fdopen (infd
, "r+"); /* open stream */
186 printf ("Too many clients.\n");
187 write (infd
, "Too many clients.\n", 18);
188 close (infd
); /* Prevent descriptor leak.. */
191 str
= fgets (string
, BUFSIZ
, infile
);
195 close (infd
); /* Prevent descriptor leak.. */
198 openfiles
[infd
] = infile
;
199 printf ("Client: %d %s", infd
, string
);
200 /* If what we read did not end in a newline,
201 it means there is more. Keep reading from the socket
202 and outputting to Emacs, until we get the newline. */
203 while (string
[strlen (string
) - 1] != '\n')
205 if (fgets (string
, BUFSIZ
, infile
) == 0)
207 printf ("%s", string
);
213 else if (FD_ISSET (rmask
, 0)) /* emacs sends codeword, fd, and string message */
215 /* Read command codeword and fd */
217 scanf ("%s %d%*c", code
, &infd
);
218 if (ferror (stdin
) || feof (stdin
))
220 fprintf (stderr
, "server: error reading from standard input\n");
224 /* Transfer text from Emacs to the client, up to a newline. */
225 infile
= openfiles
[infd
];
228 if (fgets (string
, BUFSIZ
, stdin
) == 0)
230 fprintf (infile
, "%s", string
);
231 if (string
[strlen (string
) - 1] == '\n')
236 /* If command is close, close connection to client. */
237 if (strncmp (code
, "Close:", 6) == 0)
248 #else /* This is the SYSV IPC section */
250 #include <sys/types.h>
251 #include <sys/signal.h>
265 /* "THIS has to be fixed. Remember, stderr may not exist...-rlk."
266 Incorrect. This program runs as an inferior of Emacs.
267 Its stderr always exists--rms. */
272 int s
, infd
, fromlen
, ioproc
;
274 struct msgbuf
* msgp
=
275 (struct msgbuf
*) malloc (sizeof *msgp
+ BUFSIZ
);
276 struct msqid_ds msg_st
;
278 char *homedir
, *getenv ();
283 * Create a message queue using ~/.emacs_server as the path for ftok
285 if ((homedir
= getenv ("HOME")) == NULL
)
287 fprintf (stderr
,"No home directory\n");
290 strcpy (string
, homedir
);
291 strcat (string
, "/.emacs_server");
292 creat (string
, 0600);
293 key
= ftok (string
, 1); /* unlikely to be anyone else using it */
294 s
= msgget (key
, 0600 | IPC_CREAT
);
301 /* Fork so we can close connection even if parent dies */
305 msgctl (s
, IPC_RMID
, 0);
309 signal (SIGTERM
, msgcatch
);
310 signal (SIGINT
, msgcatch
);
313 /* This is executed in the original process that did the fork above. */
314 /* Get pid of Emacs itself. */
316 setpgrp (); /* Gnu kills process group on exit */
319 /* Is Emacs still alive? */
322 msgctl (s
, IPC_RMID
, 0);
329 /* This is executed in the child made by forking above.
330 Call it c1. Make another process, ioproc. */
335 /* In process ioproc, wait for text from Emacs,
336 and send it to the process c1.
337 This way, c1 only has to wait for one source of input. */
338 while (fgets (msgp
->mtext
, BUFSIZ
, stdin
))
341 msgsnd (s
, msgp
, strlen (msgp
->mtext
) + 1, 0);
346 /* In the process c1,
347 listen for messages from clients and pass them to Emacs. */
350 if ((fromlen
= msgrcv (s
, msgp
, BUFSIZ
- 1, 1, 0)) < 0)
357 msgctl (s
, IPC_STAT
, &msg_st
);
359 /* Distinguish whether the message came from a client, or from
361 if (msg_st
.msg_lspid
== ioproc
)
366 /* Message from ioproc: tell a client we are done. */
367 msgp
->mtext
[strlen (msgp
->mtext
)-1] = 0;
368 sscanf (msgp
->mtext
, "%s %d", code
, &inproc
);
369 msgp
->mtype
= inproc
;
370 msgsnd (s
, msgp
, strlen (msgp
->mtext
) + 1, 0);
374 /* This is a request from a client: copy to stdout
375 so that Emacs will get it. Include msg_lspid
376 so server.el can tell us where to send the reply. */
377 strncpy (string
, msgp
->mtext
, fromlen
);
378 string
[fromlen
] = 0; /* make sure */
379 /* Newline is part of string.. */
380 printf ("Client: %d %s", msg_st
.msg_lspid
, string
);
386 #endif /* HAVE_SYSVIPC */
388 #endif /* HAVE_SOCKETS or HAVE_SYSVIPC */