Annotation of GNUtools/emacs/etc/server.c, revision 1.1.1.1

1.1       root        1: /* Communication subprocess for GNU Emacs acting as server.
                      2:    Copyright (C) 1986, 1987 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 1, 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 Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
                     19: 
                     20: 
                     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.  */
                     26: 
                     27: /* This must precede sys/signal.h on certain machines.  */
                     28: #include <sys/types.h>
                     29: /* This must precede config.h on certain machines.  */
                     30: #include <sys/signal.h>
                     31: 
                     32: #define NO_SHORTNAMES
                     33: #include "../src/config.h"
                     34: #undef read
                     35: #undef write
                     36: #undef open
                     37: #undef close
                     38: 
                     39: 
                     40: #if !defined(BSD) && !defined(HAVE_SYSVIPC)
                     41: #include <stdio.h>
                     42: 
                     43: main ()
                     44: {
                     45:   fprintf (stderr, "Sorry, the Emacs server is supported only on Berkeley Unix\n");
                     46:   fprintf (stderr, "or System V systems with IPC\n");
                     47:   exit (1);
                     48: }
                     49: 
                     50: #else /* BSD or HAVE_SYSVIPC */
                     51: 
                     52: #if defined (BSD) && ! defined (HAVE_SYSVIPC)
                     53: /* BSD code is very different from SYSV IPC code */
                     54: 
                     55: #include <sys/file.h>
                     56: #include <sys/types.h>
                     57: #include <sys/socket.h>
                     58: #include <sys/un.h>
                     59: #include <stdio.h>
                     60: #include <errno.h>
                     61: 
                     62: extern int errno;
                     63: 
                     64: main ()
                     65: {
                     66:   char system_name[32];
                     67:   int s, infd, fromlen;
                     68:   struct sockaddr_un server, fromunix;
                     69:   char *homedir;
                     70:   char *str, string[BUFSIZ], code[BUFSIZ];
                     71:   FILE *infile;
                     72:   FILE **openfiles;
                     73:   int openfiles_size;
                     74: 
                     75:   char *getenv ();
                     76: 
                     77:   openfiles_size = 20;
                     78:   openfiles = (FILE **) malloc (openfiles_size * sizeof (FILE *));
                     79:   if (openfiles == 0)
                     80:     abort ();
                     81: 
                     82:   /* 
                     83:    * Open up an AF_UNIX socket in this person's home directory
                     84:    */
                     85: 
                     86:   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
                     87:     {
                     88:       perror ("socket");
                     89:       exit (1);
                     90:     }
                     91:   server.sun_family = AF_UNIX;
                     92: #ifndef SERVER_HOME_DIR
                     93:   gethostname (system_name, sizeof (system_name));
                     94:   sprintf (server.sun_path, "/tmp/esrv%d-%s", geteuid (), system_name);
                     95: 
                     96:   if (unlink (server.sun_path) == -1 && errno != ENOENT)
                     97:     {
                     98:       perror ("unlink");
                     99:       exit (1);
                    100:     }
                    101: #else  
                    102:   if ((homedir = getenv ("HOME")) == NULL)
                    103:     {
                    104:       fprintf (stderr,"No home directory\n");
                    105:       exit (1);
                    106:     }
                    107:   strcpy (server.sun_path, homedir);
                    108:   strcat (server.sun_path, "/.emacs_server");
                    109:   /* Delete anyone else's old server.  */
                    110:   unlink (server.sun_path);
                    111: #endif
                    112: 
                    113:   if (bind (s, &server, strlen (server.sun_path) + 2) < 0)
                    114:     {
                    115:       perror ("bind");
                    116:       exit (1);
                    117:     }
                    118:   /*
                    119:    * Now, just wait for everything to come in..
                    120:    */
                    121:   if (listen (s, 5) < 0)
                    122:     {
                    123:       perror ("listen");
                    124:       exit (1);
                    125:     }
                    126: 
                    127:   /* Disable sigpipes in case luser kills client... */
                    128:   signal (SIGPIPE, SIG_IGN);
                    129:   for (;;)
                    130:     {
                    131:       int rmask = (1 << s) + 1;
                    132:       if (select (s + 1, &rmask, 0, 0, 0) < 0)
                    133:        perror ("select");
                    134:       if (rmask & (1 << s))    /* client sends list of filenames */
                    135:        {
                    136:          fromlen = sizeof (fromunix);
                    137:          fromunix.sun_family = AF_UNIX;
                    138:          infd = accept (s, &fromunix, &fromlen); /* open socket fd */
                    139:          if (infd < 0)
                    140:            {
                    141:              if (errno == EMFILE || errno == ENFILE)
                    142:                printf ("Too many clients.\n");
                    143:              else
                    144:                perror ("accept");
                    145:              continue;
                    146:            }
                    147: 
                    148:          if (infd >= openfiles_size)
                    149:            {
                    150:              openfiles_size *= 2;
                    151:              openfiles = (FILE **) realloc (openfiles,
                    152:                                             openfiles_size * sizeof (FILE *));
                    153:              if (openfiles == 0)
                    154:                abort ();
                    155:            }
                    156: 
                    157:          infile = fdopen (infd, "r+"); /* open stream */
                    158:          if (infile == NULL)
                    159:            {
                    160:              printf ("Too many clients.\n");
                    161:              write (infd, "Too many clients.\n", 18);
                    162:              close (infd);             /* Prevent descriptor leak.. */
                    163:              continue;
                    164:            }
                    165:          str = fgets (string, BUFSIZ, infile);
                    166:          if (str == NULL)
                    167:            {
                    168:              perror ("fgets");
                    169:              close (infd);             /* Prevent descriptor leak.. */
                    170:              continue;
                    171:            }
                    172:          openfiles[infd] = infile;
                    173:          printf ("Client: %d %s", infd, string);
                    174:          /* If what we read did not end in a newline,
                    175:             it means there is more.  Keep reading from the socket
                    176:             and outputting to Emacs, until we get the newline.  */
                    177:          while (string[strlen (string) - 1] != '\n')
                    178:            {
                    179:              if (fgets (string, BUFSIZ, infile) == 0)
                    180:                break;
                    181:              printf ("%s", string);
                    182:            }
                    183:          fflush (stdout);
                    184:          fflush (infile);
                    185:          continue;
                    186:        }
                    187:       else if (rmask & 1) /* emacs sends codeword, fd, and string message */
                    188:        {
                    189:          /* Read command codeword and fd */
                    190:          clearerr (stdin);
                    191:          scanf ("%s %d%*c", code, &infd);
                    192:          if (ferror (stdin) || feof (stdin))
                    193:            {
                    194:              fprintf (stderr, "server: error reading from standard input\n");
                    195:              exit (1);
                    196:            }
                    197: 
                    198:          /* Transfer text from Emacs to the client, up to a newline.  */
                    199:          infile = openfiles[infd];
                    200:          while (1)
                    201:            {
                    202:              if (fgets (string, BUFSIZ, stdin) == 0)
                    203:                break;
                    204:              fprintf (infile, "%s", string);
                    205:              if (string[strlen (string) - 1] == '\n')
                    206:                break;
                    207:            }
                    208:          fflush (infile);
                    209: 
                    210:          /* If command is close, close connection to client.  */
                    211:          if (strncmp (code, "Close:", 6) == 0) 
                    212:            if (infd > 2) 
                    213:              {
                    214:                fclose (infile);
                    215:                close (infd);
                    216:              }
                    217:          continue;
                    218:        } 
                    219:     }
                    220: }
                    221: 
                    222: #else  /* This is the SYSV IPC section */
                    223: 
                    224: #include <sys/types.h>
                    225: #include <sys/ipc.h>
                    226: #include <sys/msg.h>
                    227: #include <setjmp.h>
                    228: 
                    229: jmp_buf msgenv;
                    230: 
                    231: void /* void here fixes bug on sgi.
                    232:        Let's hope this doesn't break other systems.  */
                    233: msgcatch ()
                    234: {
                    235:   longjmp (msgenv, 1);
                    236: }
                    237: 
                    238: 
                    239: /* "THIS has to be fixed.  Remember, stderr may not exist...-rlk."
                    240:    Incorrect.  This program runs as an inferior of Emacs.
                    241:    Its stderr always exists--rms.  */
                    242: #include <stdio.h>
                    243: 
                    244: main ()
                    245: {
                    246:   int s, infd, fromlen;
                    247:   key_t key;
                    248:   struct msgbuf * msgp =
                    249:     (struct msgbuf *) malloc (sizeof *msgp + BUFSIZ);
                    250:   struct msqid_ds msg_st;
                    251:   int p;
                    252:   char *homedir, *getenv ();
                    253:   char string[BUFSIZ];
                    254:   FILE *infile;
                    255: 
                    256:   /*
                    257:    * Create a message queue using ~/.emacs_server as the path for ftok
                    258:    */
                    259:   if ((homedir = getenv ("HOME")) == NULL)
                    260:     {
                    261:       fprintf (stderr,"No home directory\n");
                    262:       exit (1);
                    263:     }
                    264:   strcpy (string, homedir);
                    265:   strcat (string, "/.emacs_server");
                    266:   creat (string, 0600);
                    267:   key = ftok (string, 1);      /* unlikely to be anyone else using it */
                    268:   s = msgget (key, 0600 | IPC_CREAT);
                    269:   if (s == -1)
                    270:     {
                    271:       perror ("msgget");
                    272:       exit (1);
                    273:     }
                    274: 
                    275:   /* Fork so we can close connection even if parent dies */
                    276:   p = fork ();
                    277:   if (setjmp (msgenv))
                    278:     {
                    279:       msgctl (s, IPC_RMID, 0);
                    280:       kill (p, SIGKILL);
                    281:       exit (0);
                    282:     }
                    283:   signal (SIGTERM, msgcatch);
                    284:   signal (SIGINT, msgcatch);
                    285:   /* If parent goes away, remove message box and exit */
                    286:   if (p == 0)
                    287:     {
                    288:       p = getppid ();
                    289:       setpgrp ();              /* Gnu kills process group on exit */
                    290:       while (1)
                    291:        {
                    292:          if (kill (p, 0) < 0)
                    293:            {
                    294:              msgctl (s, IPC_RMID, 0);
                    295:              exit (0);
                    296:            }
                    297:          sleep (10);
                    298:        }
                    299:     }
                    300: 
                    301:   while (1)
                    302:     {
                    303:       if ((fromlen = msgrcv (s, msgp, BUFSIZ - 1, 1, 0)) < 0)
                    304:         {
                    305:          perror ("msgrcv");
                    306:          exit (1);
                    307:         }
                    308:       else
                    309:         {
                    310:          msgctl (s, IPC_STAT, &msg_st);
                    311:          strncpy (string, msgp->mtext, fromlen);
                    312:          string[fromlen] = 0;  /* make sure */
                    313:          /* Newline is part of string.. */
                    314:          printf ("Client: %d %s", s, string); 
                    315:          fflush (stdout);
                    316:          /* Now, wait for a wakeup */
                    317:          fgets (msgp->mtext, BUFSIZ, stdin);
                    318:          msgp->mtext[strlen (msgp->mtext)-1] = 0;
                    319:          /*      strcpy (msgp->mtext, "done");*/
                    320:          msgp->mtype = msg_st.msg_lspid;
                    321:          msgsnd (s, msgp, strlen (msgp->mtext)+1, 0);
                    322:        }
                    323:     }
                    324: }
                    325: 
                    326: #endif /* SYSV IPC */
                    327: 
                    328: #endif /* BSD && IPC */
                    329: 
                    330: 

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