lib-src/emacsclient.c

   1 /* Client process that communicates with GNU Emacs acting as server.
   2    Copyright (C) 1986, 1987, 1994, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22
  23 #define NO_SHORTNAMES
  24 #include <../src/config.h>
  25 #undef signal
  26
  27 #include <stdio.h>
  28 #include <getopt.h>
  29 #ifdef HAVE_UNISTD_H
  30 #include <unistd.h>
  31 #endif
  32
  33 #ifdef VMS
  34 # include "vms-pwd.h"
  35 #else
  36 # include <pwd.h>
  37 #endif /* not VMS */
  38
  39 char *getenv (), *getwd ();
  40 char *getcwd ();
  41
  42 /* This is defined with -D from the compilation command,
  43    which extracts it from ../lisp/version.el.  */
  44
  45 #ifndef VERSION
  46 #define VERSION "unspecified"
  47 #endif
  48 \f
  49 /* Name used to invoke this program.  */
  50 char *progname;
  51
  52 /* Nonzero means don't wait for a response from Emacs.  --no-wait.  */
  53 int nowait = 0;
  54
  55 void print_help_and_exit ();
  56
  57 struct option longopts[] =
  58 {
  59   { "no-wait",  no_argument,       NULL, 'n' },
  60   { "help",     no_argument,       NULL, 'H' },
  61   { "version",  no_argument,       NULL, 'V' },
  62   { "alternate-editor",required_argument, NULL, 'a' },
  63   { 0 }
  64 };
  65
  66
  67 const char * alternate_editor = NULL;
  68
  69 /* Decode the options from argv and argc.
  70    The global variable `optind' will say how many arguments we used up.  */
  71
  72 void
  73 decode_options (argc, argv)
  74      int argc;
  75      char **argv;
  76 {
  77   while (1)
  78     {
  79       int opt = getopt_long (argc, argv,
  80                              "VHna:", longopts, 0);
  81
  82       if (opt == EOF)
  83         break;
  84
  85       alternate_editor = getenv ("ALTERNATE_EDITOR");
  86
  87       switch (opt)
  88         {
  89         case 0:
  90           /* If getopt returns 0, then it has already processed a
  91              long-named option.  We should do nothing.  */
  92           break;
  93
  94         case 'a':
  95           alternate_editor = optarg;
  96           break;
  97
  98         case 'n':
  99           nowait = 1;
 100           break;
 101
 102         case 'V':
 103           fprintf (stderr, "emacsclient %s\n", VERSION);
 104           exit (1);
 105           break;
 106
 107         case 'H':
 108         default:
 109           print_help_and_exit ();
 110         }
 111     }
 112 }
 113
 114 void
 115 print_help_and_exit ()
 116 {
 117   fprintf (stderr,
 118            "Usage: %s [-a ALTERNATE-EDITOR] [-n] [--no-wait] [+LINENUMBER] FILENAME\n",
 119            progname);
 120   fprintf (stderr,
 121            "Or %s --version\n",
 122            progname);
 123   fprintf (stderr,
 124            "Report bugs to bug-gnu-emacs@gnu.org.\n");
 125   exit (1);
 126 }
 127
 128 /* Return a copy of NAME, inserting a &
 129    before each &, each space, and any initial -.
 130    Change spaces to underscores, too, so that the
 131    return value never contains a space.  */
 132
 133 char *
 134 quote_file_name (name)
 135      char *name;
 136 {
 137   char *copy = (char *) malloc (strlen (name) * 2 + 1);
 138   char *p, *q;
 139
 140   p = name;
 141   q = copy;
 142   while (*p)
 143     {
 144       if (*p == ' ')
 145         {
 146           *q++ = '&';
 147           *q++ = '_';
 148           p++;
 149         }
 150       else
 151         {
 152           if (*p == '&' || (*p == '-' && p == name))
 153             *q++ = '&';
 154           *q++ = *p++;
 155         }
 156     }
 157   *q++ = 0;
 158
 159
 160   return copy;
 161 }
 162
 163 /* Like malloc but get fatal error if memory is exhausted.  */
 164
 165 long *
 166 xmalloc (size)
 167      unsigned int size;
 168 {
 169   long *result = (long *) malloc (size);
 170   if (result == NULL)
 171   {
 172     perror ("malloc");
 173     exit (1);
 174   }
 175   return result;
 176 }
 177 \f
 178 /*
 179   Try to run a different command, or --if no alternate editor is
 180   defined-- exit with an errorcode.
 181 */
 182 void
 183 fail (argc, argv)
 184      int argc;
 185      char **argv;
 186 {
 187   if (alternate_editor)
 188     {
 189       int i = optind -1 ;
 190       execvp (alternate_editor, argv + i);
 191       return;
 192     }
 193   else
 194     {
 195       exit (1);
 196     }
 197 }
 198
 199
 200
 201 \f
 202 #if !defined (HAVE_SOCKETS) && !defined (HAVE_SYSVIPC)
 203
 204 int
 205 main (argc, argv)
 206      int argc;
 207      char **argv;
 208 {
 209   fprintf (stderr, "%s: Sorry, the Emacs server is supported only\n",
 210            argv[0]);
 211   fprintf (stderr, "on systems with Berkeley sockets or System V IPC.\n");
 212
 213   fail (argc, argv);
 214 }
 215
 216 #else /* HAVE_SOCKETS or HAVE_SYSVIPC */
 217
 218 #if defined (HAVE_SOCKETS) && ! defined (NO_SOCKETS_IN_FILE_SYSTEM)
 219 /* BSD code is very different from SYSV IPC code */
 220
 221 #include <sys/types.h>
 222 #include <sys/socket.h>
 223 #include <sys/un.h>
 224 #include <sys/stat.h>
 225 #include <errno.h>
 226
 227 extern char *strerror ();
 228 extern int errno;
 229
 230 /* Three possibilities:
 231    2 - can't be `stat'ed                (sets errno)
 232    1 - isn't owned by us
 233    0 - success: none of the above */
 234
 235 static int
 236 socket_status (socket_name)
 237      char *socket_name;
 238 {
 239   struct stat statbfr;
 240
 241   if (stat (socket_name, &statbfr) == -1)
 242     return 2;
 243
 244   if (statbfr.st_uid != geteuid ())
 245     return 1;
 246
 247   return 0;
 248 }
 249
 250 int
 251 main (argc, argv)
 252      int argc;
 253      char **argv;
 254 {
 255   char *system_name;
 256   int system_name_length;
 257   int s, i;
 258   FILE *out, *in;
 259   struct sockaddr_un server;
 260 #ifdef SERVER_HOME_DIR
 261   char *homedir;
 262 #endif
 263   char *cwd, *str;
 264   char string[BUFSIZ];
 265
 266   progname = argv[0];
 267
 268   /* Process options.  */
 269   decode_options (argc, argv);
 270
 271   if (argc - optind < 1)
 272     print_help_and_exit ();
 273
 274   /*
 275    * Open up an AF_UNIX socket in this person's home directory
 276    */
 277
 278   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
 279     {
 280       fprintf (stderr, "%s: ", argv[0]);
 281       perror ("socket");
 282       fail (argc, argv);
 283     }
 284
 285   server.sun_family = AF_UNIX;
 286
 287   {
 288     system_name_length = 32;
 289
 290     while (1)
 291       {
 292         system_name = (char *) xmalloc (system_name_length + 1);
 293
 294         /* system_name must be null-terminated string.  */
 295         system_name[system_name_length] = '\0';
 296
 297         if (gethostname (system_name, system_name_length) == 0)
 298           break;
 299
 300         free (system_name);
 301         system_name_length *= 2;
 302       }
 303   }
 304
 305 #ifndef SERVER_HOME_DIR
 306   {
 307     int sock_status = 0;
 308
 309     sprintf (server.sun_path, "/tmp/esrv%d-%s", (int) geteuid (), system_name);
 310
 311     /* See if the socket exists, and if it's owned by us. */
 312     sock_status = socket_status (server.sun_path);
 313     if (sock_status)
 314       {
 315         /* Failing that, see if LOGNAME or USER exist and differ from
 316            our euid.  If so, look for a socket based on the UID
 317            associated with the name.  This is reminiscent of the logic
 318            that init_editfns uses to set the global Vuser_full_name.  */
 319
 320         char *user_name = (char *) getenv ("LOGNAME");
 321         if (!user_name)
 322           user_name = (char *) getenv ("USER");
 323
 324         if (user_name)
 325           {
 326             struct passwd *pw = getpwnam (user_name);
 327             if (pw && (pw->pw_uid != geteuid ()))
 328               {
 329                 /* We're running under su, apparently. */
 330                 sprintf (server.sun_path, "/tmp/esrv%d-%s",
 331                          (int) pw->pw_uid, system_name);
 332                 sock_status = socket_status (server.sun_path);
 333               }
 334           }
 335       }
 336
 337      switch (sock_status)
 338        {
 339        case 1:
 340          /* There's a socket, but it isn't owned by us.  This is OK if
 341             we are root. */
 342          if (0 != geteuid ())
 343            {
 344              fprintf (stderr, "%s: Invalid socket owner\n", argv[0]);
 345              fail (argc, argv);
 346            }
 347          break;
 348
 349        case 2:
 350          /* `stat' failed */
 351          if (errno == ENOENT)
 352            fprintf (stderr,
 353                     "%s: can't find socket; have you started the server?\n",
 354                     argv[0]);
 355          else
 356            fprintf (stderr, "%s: can't stat %s: %s\n",
 357                     argv[0], server.sun_path, strerror (errno));
 358          fail (argc, argv);
 359          break;
 360        }
 361   }
 362 #else
 363   if ((homedir = getenv ("HOME")) == NULL)
 364     {
 365       fprintf (stderr, "%s: No home directory\n", argv[0]);
 366       fail (argc, argv);
 367     }
 368   strcpy (server.sun_path, homedir);
 369   strcat (server.sun_path, "/.emacs-server-");
 370   strcat (server.sun_path, system_name);
 371 #endif
 372
 373   if (connect (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2)
 374       < 0)
 375     {
 376       fprintf (stderr, "%s: ", argv[0]);
 377       perror ("connect");
 378       fail (argc, argv);
 379     }
 380
 381   /* We use the stream OUT to send our command to the server.  */
 382   if ((out = fdopen (s, "r+")) == NULL)
 383     {
 384       fprintf (stderr, "%s: ", argv[0]);
 385       perror ("fdopen");
 386       fail (argc, argv);
 387     }
 388
 389   /* We use the stream IN to read the response.
 390      We used to use just one stream for both output and input
 391      on the socket, but reversing direction works nonportably:
 392      on some systems, the output appears as the first input;
 393      on other systems it does not.  */
 394   if ((in = fdopen (s, "r+")) == NULL)
 395     {
 396       fprintf (stderr, "%s: ", argv[0]);
 397       perror ("fdopen");
 398       fail (argc, argv);
 399     }
 400
 401 #ifdef BSD_SYSTEM
 402   cwd = getwd (string);
 403 #else
 404   cwd = getcwd (string, sizeof string);
 405 #endif
 406   if (cwd == 0)
 407     {
 408       /* getwd puts message in STRING if it fails.  */
 409       fprintf (stderr, "%s: %s (%s)\n", argv[0],
 410 #ifdef BSD_SYSTEM
 411                string,
 412 #else
 413                "Cannot get current working directory",
 414 #endif
 415                strerror (errno));
 416       fail (argc, argv);
 417     }
 418
 419   if (nowait)
 420     fprintf (out, "-nowait ");
 421
 422   for (i = optind; i < argc; i++)
 423     {
 424       if (*argv[i] == '+')
 425         {
 426           char *p = argv[i] + 1;
 427           while (*p >= '0' && *p <= '9') p++;
 428           if (*p != 0)
 429             fprintf (out, "%s/", quote_file_name (cwd));
 430         }
 431       else if (*argv[i] != '/')
 432         fprintf (out, "%s/", quote_file_name (cwd));
 433
 434       fprintf (out, "%s ", quote_file_name (argv[i]));
 435     }
 436   fprintf (out, "\n");
 437   fflush (out);
 438
 439   /* Maybe wait for an answer.   */
 440   if (nowait)
 441     return 0;
 442
 443   printf ("Waiting for Emacs...");
 444   fflush (stdout);
 445
 446   /* Now, wait for an answer and print any messages.  On some systems,
 447      the first line we read will actually be the output we just sent.
 448      We can't predict whether that will happen, so if it does, we
 449      detect it by recognizing `Client: ' at the beginning.  */
 450
 451   while (str = fgets (string, BUFSIZ, in))
 452     printf ("%s", str);
 453
 454   return 0;
 455 }
 456
 457 #else /* This is the SYSV IPC section */
 458
 459 #include <sys/types.h>
 460 #include <sys/ipc.h>
 461 #include <sys/msg.h>
 462 #include <sys/utsname.h>
 463 #include <stdio.h>
 464 #include <errno.h>
 465 extern int errno;
 466
 467 char *getwd (), *getcwd (), *getenv ();
 468 struct utsname system_name;
 469
 470 main (argc, argv)
 471      int argc;
 472      char **argv;
 473 {
 474   int s;
 475   key_t key;
 476   /* Size of text allocated in MSGP.  */
 477   int size_allocated = BUFSIZ;
 478   /* Amount of text used in MSGP.  */
 479   int used;
 480   struct msgbuf *msgp
 481     = (struct msgbuf *) malloc (sizeof (struct msgbuf) + size_allocated);
 482   struct msqid_ds * msg_st;
 483   char *homedir, buf[BUFSIZ];
 484   char gwdirb[BUFSIZ];
 485   char *cwd;
 486   char *temp;
 487
 488   progname = argv[0];
 489
 490   /* Process options.  */
 491   decode_options (argc, argv);
 492
 493   if (argc - optind < 1)
 494     print_help_and_exit ();
 495
 496   /*
 497    * Create a message queue using ~/.emacs-server as the path for ftok
 498    */
 499   if ((homedir = getenv ("HOME")) == NULL)
 500     {
 501       fprintf (stderr, "%s: No home directory\n", argv[0]);
 502       exit (1);
 503     }
 504   strcpy (buf, homedir);
 505 #ifndef HAVE_LONG_FILE_NAMES
 506   /* If file names are short, we can't fit the host name.  */
 507   strcat (buf, "/.emacs-server");
 508 #else
 509   strcat (buf, "/.emacs-server-");
 510   uname (&system_name);
 511   strcat (buf, system_name.nodename);
 512 #endif
 513   creat (buf, 0600);
 514   key = ftok (buf, 1);  /* unlikely to be anyone else using it */
 515   s = msgget (key, 0600 | IPC_CREAT);
 516   if (s == -1)
 517     {
 518       fprintf (stderr, "%s: ", argv[0]);
 519       perror ("msgget");
 520       exit (1);
 521     }
 522
 523   /* Determine working dir, so we can prefix it to all the arguments.  */
 524 #ifdef BSD_SYSTEM
 525   temp = getwd (gwdirb);
 526 #else
 527   temp = getcwd (gwdirb, sizeof gwdirb);
 528 #endif
 529
 530   cwd = gwdirb;
 531   if (temp != 0)
 532     {
 533       /* On some systems, cwd can look like `@machine/...';
 534          ignore everything before the first slash in such a case.  */
 535       while (*cwd && *cwd != '/')
 536         cwd++;
 537       strcat (cwd, "/");
 538     }
 539   else
 540     {
 541 #ifdef BSD_SYSTEM
 542       fprintf (stderr, "%s: %s\n", argv[0], cwd);
 543 #else
 544       fprintf (stderr, "%s: Cannot get current working directory: %s\n",
 545                argv[0], strerror (errno));
 546 #endif
 547       fail (argc, argv);
 548     }
 549
 550   msgp->mtext[0] = 0;
 551   used = 0;
 552
 553   if (nowait)
 554     {
 555       strcat (msgp->mtext, "-nowait ");
 556       used += 8;
 557     }
 558
 559   argc -= optind;
 560   argv += optind;
 561
 562   while (argc)
 563     {
 564       int need_cwd = 0;
 565       char *modified_arg = argv[0];
 566
 567       if (*modified_arg == '+')
 568         {
 569           char *p = modified_arg + 1;
 570           while (*p >= '0' && *p <= '9') p++;
 571           if (*p != 0)
 572             need_cwd = 1;
 573         }
 574       else if (*modified_arg != '/')
 575         need_cwd = 1;
 576
 577       modified_arg = quote_file_name (modified_arg);
 578
 579       if (need_cwd)
 580         /* Overestimate in case we have to quote something in CWD.  */
 581         used += 2 * strlen (cwd);
 582       used += strlen (modified_arg) + 1;
 583       while (used + 2 > size_allocated)
 584         {
 585           size_allocated *= 2;
 586           msgp = (struct msgbuf *) realloc (msgp,
 587                                             (sizeof (struct msgbuf)
 588                                              + size_allocated));
 589         }
 590
 591       if (need_cwd)
 592         strcat (msgp->mtext, quote_file_name (cwd));
 593
 594       strcat (msgp->mtext, modified_arg);
 595       strcat (msgp->mtext, " ");
 596       argv++; argc--;
 597     }
 598   strcat (msgp->mtext, "\n");
 599 #ifdef HPUX /* HPUX has a bug.  */
 600   if (strlen (msgp->mtext) >= 512)
 601     {
 602       fprintf (stderr, "%s: args too long for msgsnd\n", progname);
 603       fail (argc, argv);
 604     }
 605 #endif
 606   msgp->mtype = 1;
 607   if (msgsnd (s, msgp, strlen (msgp->mtext)+1, 0) < 0)
 608     {
 609       fprintf (stderr, "%s: ", progname);
 610       perror ("msgsnd");
 611       fail (argc, argv);
 612     }
 613
 614   /* Maybe wait for an answer.   */
 615   if (nowait)
 616     return 0;
 617
 618   printf ("Waiting for Emacs...");
 619   fflush (stdout);
 620
 621   msgrcv (s, msgp, BUFSIZ, getpid (), 0);       /* wait for anything back */
 622   strcpy (buf, msgp->mtext);
 623
 624   printf ("\n");
 625   if (*buf)
 626     printf ("%s\n", buf);
 627   exit (0);
 628 }
 629
 630 #endif /* HAVE_SYSVIPC */
 631
 632 #endif /* HAVE_SOCKETS or HAVE_SYSVIPC */
 633 \f
 634 #ifndef HAVE_STRERROR
 635 char *
 636 strerror (errnum)
 637      int errnum;
 638 {
 639   extern char *sys_errlist[];
 640   extern int sys_nerr;
 641
 642   if (errnum >= 0 && errnum < sys_nerr)
 643     return sys_errlist[errnum];
 644   return (char *) "Unknown error";
 645 }
 646
 647 #endif /* ! HAVE_STRERROR */