lib-src/emacsclient.c

   1 /* Client process that communicates with GNU Emacs acting as server.
   2    Copyright (C) 1986, 1987, 1994, 1999, 2000, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007 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., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22
  23 #define NO_SHORTNAMES
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #ifdef WINDOWSNT
  30
  31 /* config.h defines these, which disables sockets altogether! */
  32 # undef _WINSOCKAPI_
  33 # undef _WINSOCK_H
  34
  35 # include <malloc.h>
  36 # include <stdlib.h>
  37 # include <windows.h>
  38
  39 # define NO_SOCKETS_IN_FILE_SYSTEM
  40
  41 # define HSOCKET SOCKET
  42 # define CLOSE_SOCKET closesocket
  43 # define INITIALIZE() (initialize_sockets ())
  44
  45 #else /* !WINDOWSNT */
  46
  47 # include <sys/types.h>
  48
  49 # ifdef HAVE_INET_SOCKETS
  50 #  include <netinet/in.h>
  51 # endif
  52
  53 # define INVALID_SOCKET -1
  54 # define HSOCKET int
  55 # define CLOSE_SOCKET close
  56 # define INITIALIZE()
  57
  58 #endif /* !WINDOWSNT */
  59
  60 #undef signal
  61
  62 #include <stdarg.h>
  63 #include <ctype.h>
  64 #include <stdio.h>
  65 #include "getopt.h"
  66 #ifdef HAVE_UNISTD_H
  67 #include <unistd.h>
  68 #endif
  69
  70 #ifdef VMS
  71 # include "vms-pwd.h"
  72 #else /* not VMS */
  73 #ifdef WINDOWSNT
  74 # include <io.h>
  75 #else /* not WINDOWSNT */
  76 # include <pwd.h>
  77 #endif /* not WINDOWSNT */
  78 #endif /* not VMS */
  79
  80 char *getenv (), *getwd ();
  81 char *(getcwd) ();
  82
  83 #ifndef VERSION
  84 #define VERSION "unspecified"
  85 #endif
  86 \f
  87 #define SEND_STRING(data) (send_to_emacs (s, (data)))
  88 #define SEND_QUOTED(data) (quote_file_name (s, (data)))
  89
  90 #ifndef EXIT_SUCCESS
  91 #define EXIT_SUCCESS 0
  92 #endif
  93
  94 #ifndef EXIT_FAILURE
  95 #define EXIT_FAILURE 1
  96 #endif
  97
  98 #ifndef FALSE
  99 #define FALSE 0
 100 #endif
 101
 102 #ifndef TRUE
 103 #define TRUE 1
 104 #endif
 105
 106 #ifndef NO_RETURN
 107 #define NO_RETURN
 108 #endif
 109 \f
 110 /* Name used to invoke this program.  */
 111 char *progname;
 112
 113 /* Nonzero means don't wait for a response from Emacs.  --no-wait.  */
 114 int nowait = 0;
 115
 116 /* Nonzero means args are expressions to be evaluated.  --eval.  */
 117 int eval = 0;
 118
 119 /* The display on which Emacs should work.  --display.  */
 120 char *display = NULL;
 121
 122 /* If non-NULL, the name of an editor to fallback to if the server
 123    is not running.  --alternate-editor.   */
 124 const char *alternate_editor = NULL;
 125
 126 /* If non-NULL, the filename of the UNIX socket.  */
 127 char *socket_name = NULL;
 128
 129 /* If non-NULL, the filename of the authentication file.  */
 130 char *server_file = NULL;
 131
 132 /* PID of the Emacs server process.  */
 133 int emacs_pid = 0;
 134
 135 void print_help_and_exit () NO_RETURN;
 136
 137 struct option longopts[] =
 138 {
 139   { "no-wait",  no_argument,       NULL, 'n' },
 140   { "eval",     no_argument,       NULL, 'e' },
 141   { "help",     no_argument,       NULL, 'H' },
 142   { "version",  no_argument,       NULL, 'V' },
 143   { "alternate-editor", required_argument, NULL, 'a' },
 144 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 145   { "socket-name",      required_argument, NULL, 's' },
 146 #endif
 147   { "server-file",      required_argument, NULL, 'f' },
 148   { "display",  required_argument, NULL, 'd' },
 149   { 0, 0, 0, 0 }
 150 };
 151
 152 /* Message functions. */
 153
 154 #ifdef WINDOWSNT
 155 int
 156 w32_window_app ()
 157 {
 158   static int window_app = -1;
 159   char szTitle[MAX_PATH];
 160
 161   if (window_app < 0)
 162     /* Checking for STDOUT does not work; it's a valid handle also in
 163        nonconsole apps.  Testing for the console title seems to work. */
 164     window_app = (GetConsoleTitleA (szTitle, MAX_PATH) == 0);
 165
 166   return window_app;
 167 }
 168 #endif
 169
 170 void
 171 message (int is_error, char *message, ...)
 172 {
 173   char msg [2048];
 174   va_list args;
 175
 176   va_start (args, message);
 177   vsprintf (msg, message, args);
 178   va_end (args);
 179
 180 #ifdef WINDOWSNT
 181   if (w32_window_app ())
 182     {
 183       if (is_error)
 184         MessageBox (NULL, msg, "Emacsclient ERROR", MB_ICONERROR);
 185       else
 186         MessageBox (NULL, msg, "Emacsclient", MB_ICONINFORMATION);
 187     }
 188   else
 189 #endif
 190     {
 191       FILE *f = is_error ? stderr : stdout;
 192
 193       fputs (msg, f);
 194       fflush (f);
 195     }
 196 }
 197
 198 /* Decode the options from argv and argc.
 199    The global variable `optind' will say how many arguments we used up.  */
 200
 201 void
 202 decode_options (argc, argv)
 203      int argc;
 204      char **argv;
 205 {
 206   alternate_editor = getenv ("ALTERNATE_EDITOR");
 207
 208   while (1)
 209     {
 210       int opt = getopt_long (argc, argv,
 211 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 212                              "VHnea:s:f:d:",
 213 #else
 214                              "VHnea:f:d:",
 215 #endif
 216                              longopts, 0);
 217
 218       if (opt == EOF)
 219         break;
 220
 221       switch (opt)
 222         {
 223         case 0:
 224           /* If getopt returns 0, then it has already processed a
 225              long-named option.  We should do nothing.  */
 226           break;
 227
 228         case 'a':
 229           alternate_editor = optarg;
 230           break;
 231
 232 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 233         case 's':
 234           socket_name = optarg;
 235           break;
 236 #endif
 237
 238         case 'f':
 239           server_file = optarg;
 240           break;
 241
 242         case 'd':
 243           display = optarg;
 244           break;
 245
 246         case 'n':
 247           nowait = 1;
 248           break;
 249
 250         case 'e':
 251           eval = 1;
 252           break;
 253
 254         case 'V':
 255           message (FALSE, "emacsclient %s\n", VERSION);
 256           exit (EXIT_SUCCESS);
 257           break;
 258
 259         case 'H':
 260           print_help_and_exit ();
 261           break;
 262
 263         default:
 264           message (TRUE, "Try `%s --help' for more information\n", progname);
 265           exit (EXIT_FAILURE);
 266           break;
 267         }
 268     }
 269 }
 270
 271 void
 272 print_help_and_exit ()
 273 {
 274   message (FALSE,
 275           "Usage: %s [OPTIONS] FILE...\n\
 276 Tell the Emacs server to visit the specified files.\n\
 277 Every FILE can be either just a FILENAME or [+LINE[:COLUMN]] FILENAME.\n\
 278 \n\
 279 The following OPTIONS are accepted:\n\
 280 \n\
 281 -V, --version           Just print version info and return\n\
 282 -H, --help              Print this usage information message\n\
 283 -e, --eval              Evaluate FILE arguments as Lisp expressions\n\
 284 -n, --no-wait           Don't wait for the server to return\n\
 285 -d, --display=DISPLAY   Visit the file in the given display\n"
 286 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 287 "-s, --socket-name=FILENAME\n\
 288                         Set filename of the UNIX socket for communication\n"
 289 #endif
 290 "-f, --server-file=FILENAME\n\
 291                         Set filename of the TCP authentication file\n\
 292 -a, --alternate-editor=EDITOR\n\
 293                         Editor to fallback to if server is not running\n\
 294 \n\
 295 Report bugs to bug-gnu-emacs@gnu.org.\n", progname);
 296   exit (EXIT_SUCCESS);
 297 }
 298
 299 \f
 300 #ifdef WINDOWSNT
 301
 302 /*
 303   execvp wrapper for Windows. Quotes arguments with embedded spaces.
 304
 305   This is necessary due to the broken implementation of exec* routines in
 306   the Microsoft libraries: they concatenate the arguments together without
 307   quoting special characters, and pass the result to CreateProcess, with
 308   predictably bad results.  By contrast, Posix execvp passes the arguments
 309   directly into the argv array of the child process.
 310 */
 311 int
 312 w32_execvp (path, argv)
 313      char *path;
 314      char **argv;
 315 {
 316   int i;
 317
 318   /* Required to allow a .BAT script as alternate editor.  */
 319   argv[0] = (char *) alternate_editor;
 320
 321   for (i = 0; argv[i]; i++)
 322     if (strchr (argv[i], ' '))
 323       {
 324         char *quoted = alloca (strlen (argv[i]) + 3);
 325         sprintf (quoted, "\"%s\"", argv[i]);
 326         argv[i] = quoted;
 327       }
 328
 329   return execvp (path, argv);
 330 }
 331
 332 #undef execvp
 333 #define execvp w32_execvp
 334
 335 #endif /* WINDOWSNT */
 336
 337 /*
 338   Try to run a different command, or --if no alternate editor is
 339   defined-- exit with an errorcode.
 340 */
 341 void
 342 fail (argc, argv)
 343      int argc;
 344      char **argv;
 345 {
 346   if (alternate_editor)
 347     {
 348       int i = optind - 1;
 349
 350       execvp (alternate_editor, argv + i);
 351       message (TRUE, "%s: error executing alternate editor \"%s\"\n",
 352                progname, alternate_editor);
 353     }
 354   exit (EXIT_FAILURE);
 355 }
 356
 357 \f
 358 #if !defined (HAVE_SOCKETS) || !defined (HAVE_INET_SOCKETS)
 359
 360 int
 361 main (argc, argv)
 362      int argc;
 363      char **argv;
 364 {
 365   message (TRUE, "%s: Sorry, the Emacs server is supported only\non systems with Berkely sockets.\n",
 366            argv[0]);
 367
 368   fail (argc, argv);
 369 }
 370
 371 #else /* HAVE_SOCKETS && HAVE_INET_SOCKETS */
 372
 373 #ifdef WINDOWSNT
 374 # include <winsock2.h>
 375 #else
 376 # include <sys/types.h>
 377 # include <sys/socket.h>
 378 # include <sys/un.h>
 379 # include <sys/stat.h>
 380 # include <errno.h>
 381 #endif
 382
 383 #define AUTH_KEY_LENGTH      64
 384 #define SEND_BUFFER_SIZE   4096
 385
 386 extern char *strerror ();
 387 extern int errno;
 388
 389 /* Buffer to accumulate data to send in TCP connections.  */
 390 char send_buffer[SEND_BUFFER_SIZE + 1];
 391 int sblen = 0;  /* Fill pointer for the send buffer.  */
 392
 393 /* Let's send the data to Emacs when either
 394    - the data ends in "\n", or
 395    - the buffer is full (but this shouldn't happen)
 396    Otherwise, we just accumulate it.  */
 397 void
 398 send_to_emacs (s, data)
 399      HSOCKET s;
 400      char *data;
 401 {
 402   while (data)
 403     {
 404       int dlen = strlen (data);
 405       if (dlen + sblen >= SEND_BUFFER_SIZE)
 406         {
 407           int part = SEND_BUFFER_SIZE - sblen;
 408           strncpy (&send_buffer[sblen], data, part);
 409           data += part;
 410           sblen = SEND_BUFFER_SIZE;
 411         }
 412       else if (dlen)
 413         {
 414           strcpy (&send_buffer[sblen], data);
 415           data = NULL;
 416           sblen += dlen;
 417         }
 418       else
 419         break;
 420
 421       if (sblen == SEND_BUFFER_SIZE
 422           || (sblen > 0 && send_buffer[sblen-1] == '\n'))
 423         {
 424           int sent = send (s, send_buffer, sblen, 0);
 425           if (sent != sblen)
 426             strcpy (send_buffer, &send_buffer[sent]);
 427           sblen -= sent;
 428         }
 429     }
 430 }
 431
 432 /* In NAME, insert a & before each &, each space, each newline, and
 433    any initial -.  Change spaces to underscores, too, so that the
 434    return value never contains a space.  */
 435 void
 436 quote_file_name (s, name)
 437      HSOCKET s;
 438      char *name;
 439 {
 440   char *copy = (char *) malloc (strlen (name) * 2 + 1);
 441   char *p, *q;
 442
 443   p = name;
 444   q = copy;
 445   while (*p)
 446     {
 447       if (*p == ' ')
 448         {
 449           *q++ = '&';
 450           *q++ = '_';
 451           p++;
 452         }
 453       else if (*p == '\n')
 454         {
 455           *q++ = '&';
 456           *q++ = 'n';
 457           p++;
 458         }
 459       else
 460         {
 461           if (*p == '&' || (*p == '-' && p == name))
 462             *q++ = '&';
 463           *q++ = *p++;
 464         }
 465     }
 466   *q++ = 0;
 467
 468   SEND_STRING (copy);
 469
 470   free (copy);
 471 }
 472
 473 int
 474 file_name_absolute_p (filename)
 475      const unsigned char *filename;
 476 {
 477   /* Sanity check, it shouldn't happen.  */
 478   if (! filename) return FALSE;
 479
 480   /* /xxx is always an absolute path.  */
 481   if (filename[0] == '/') return TRUE;
 482
 483   /* Empty filenames (which shouldn't happen) are relative.  */
 484   if (filename[0] == '\0') return FALSE;
 485
 486 #ifdef WINDOWSNT
 487   /* X:\xxx is always absolute; X:xxx is an error and will fail.  */
 488   if (isalpha (filename[0])
 489       && filename[1] == ':' && (filename[2] == '\\' || filename[2] == '/'))
 490     return TRUE;
 491
 492   /* Both \xxx and \\xxx\yyy are absolute.  */
 493   if (filename[0] == '\\') return TRUE;
 494 #endif
 495
 496   return FALSE;
 497 }
 498
 499 #ifdef WINDOWSNT
 500 /* Wrapper to make WSACleanup a cdecl, as required by atexit.  */
 501 void
 502 __cdecl close_winsock ()
 503 {
 504   WSACleanup ();
 505 }
 506
 507 /* Initialize the WinSock2 library.  */
 508 void
 509 initialize_sockets ()
 510 {
 511   WSADATA wsaData;
 512
 513   if (WSAStartup (MAKEWORD (2, 0), &wsaData))
 514     {
 515       message (TRUE, "%s: error initializing WinSock2", progname);
 516       exit (EXIT_FAILURE);
 517     }
 518
 519   atexit (close_winsock);
 520 }
 521 #endif /* WINDOWSNT */
 522 \f
 523 /*
 524  * Read the information needed to set up a TCP comm channel with
 525  * the Emacs server: host, port, pid and authentication string.
 526  */
 527 int
 528 get_server_config (server, authentication)
 529      struct sockaddr_in *server;
 530      char *authentication;
 531 {
 532   char dotted[32];
 533   char *port;
 534   char *pid;
 535   FILE *config = NULL;
 536
 537   if (file_name_absolute_p (server_file))
 538     config = fopen (server_file, "rb");
 539   else
 540     {
 541       char *home = getenv ("HOME");
 542
 543       if (home)
 544         {
 545           char *path = alloca (32 + strlen (home) + strlen (server_file));
 546           sprintf (path, "%s/.emacs.d/server/%s", home, server_file);
 547           config = fopen (path, "rb");
 548         }
 549 #ifdef WINDOWSNT
 550       if (!config && (home = getenv ("APPDATA")))
 551         {
 552           char *path = alloca (32 + strlen (home) + strlen (server_file));
 553           sprintf (path, "%s/.emacs.d/server/%s", home, server_file);
 554           config = fopen (path, "rb");
 555         }
 556 #endif
 557     }
 558
 559   if (! config)
 560     return FALSE;
 561
 562   if (fgets (dotted, sizeof dotted, config)
 563       && (port = strchr (dotted, ':'))
 564       && (pid = strchr (port, ' ')))
 565     {
 566       *port++ = '\0';
 567       *pid++  = '\0';
 568     }
 569   else
 570     {
 571       message (TRUE, "%s: invalid configuration info", progname);
 572       exit (EXIT_FAILURE);
 573     }
 574
 575   server->sin_family = AF_INET;
 576   server->sin_addr.s_addr = inet_addr (dotted);
 577   server->sin_port = htons (atoi (port));
 578
 579   if (! fread (authentication, AUTH_KEY_LENGTH, 1, config))
 580     {
 581       message (TRUE, "%s: cannot read authentication info", progname);
 582       exit (EXIT_FAILURE);
 583     }
 584
 585   fclose (config);
 586
 587   emacs_pid = atoi (pid);
 588
 589   return TRUE;
 590 }
 591
 592 HSOCKET
 593 set_tcp_socket ()
 594 {
 595   HSOCKET s;
 596   struct sockaddr_in server;
 597   struct linger l_arg = {1, 1};
 598   char auth_string[AUTH_KEY_LENGTH + 1];
 599
 600   if (! get_server_config (&server, auth_string))
 601     return INVALID_SOCKET;
 602
 603   if (server.sin_addr.s_addr != inet_addr ("127.0.0.1"))
 604     message (FALSE, "%s: connected to remote socket at %s\n",
 605              progname, inet_ntoa (server.sin_addr));
 606
 607   /*
 608    * Open up an AF_INET socket
 609    */
 610   if ((s = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
 611     {
 612       message (TRUE, "%s: socket: %s\n", progname, strerror (errno));
 613       return INVALID_SOCKET;
 614     }
 615
 616   /*
 617    * Set up the socket
 618    */
 619   if (connect (s, (struct sockaddr *) &server, sizeof server) < 0)
 620     {
 621       message (TRUE, "%s: connect: %s\n", progname, strerror (errno));
 622       return INVALID_SOCKET;
 623     }
 624
 625   setsockopt (s, SOL_SOCKET, SO_LINGER, (char *) &l_arg, sizeof l_arg);
 626
 627   /*
 628    * Send the authentication
 629    */
 630   auth_string[AUTH_KEY_LENGTH] = '\0';
 631
 632   SEND_STRING ("-auth ");
 633   SEND_STRING (auth_string);
 634   SEND_STRING ("\n");
 635
 636   return s;
 637 }
 638
 639 #if !defined (NO_SOCKETS_IN_FILE_SYSTEM)
 640
 641 /* Three possibilities:
 642    2 - can't be `stat'ed                (sets errno)
 643    1 - isn't owned by us
 644    0 - success: none of the above */
 645
 646 static int
 647 socket_status (socket_name)
 648      char *socket_name;
 649 {
 650   struct stat statbfr;
 651
 652   if (stat (socket_name, &statbfr) == -1)
 653     return 2;
 654
 655   if (statbfr.st_uid != geteuid ())
 656     return 1;
 657
 658   return 0;
 659 }
 660
 661 HSOCKET
 662 set_local_socket ()
 663 {
 664   HSOCKET s;
 665   struct sockaddr_un server;
 666
 667   /*
 668    * Open up an AF_UNIX socket in this person's home directory
 669    */
 670
 671   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
 672     {
 673       message (TRUE, "%s: socket: %s\n", progname, strerror (errno));
 674       return INVALID_SOCKET;
 675     }
 676
 677   server.sun_family = AF_UNIX;
 678
 679   {
 680     int sock_status = 0;
 681     int default_sock = !socket_name;
 682     int saved_errno;
 683     char *server_name = "server";
 684
 685     if (socket_name && !index (socket_name, '/') && !index (socket_name, '\\'))
 686       { /* socket_name is a file name component.  */
 687         server_name = socket_name;
 688         socket_name = NULL;
 689         default_sock = 1;       /* Try both UIDs.  */
 690       }
 691
 692     if (default_sock)
 693       {
 694         socket_name = alloca (100 + strlen (server_name));
 695         sprintf (socket_name, "/tmp/emacs%d/%s",
 696                  (int) geteuid (), server_name);
 697       }
 698
 699     if (strlen (socket_name) < sizeof (server.sun_path))
 700       strcpy (server.sun_path, socket_name);
 701     else
 702       {
 703         message (TRUE, "%s: socket-name %s too long",
 704                  progname, socket_name);
 705         exit (EXIT_FAILURE);
 706       }
 707
 708     /* See if the socket exists, and if it's owned by us. */
 709     sock_status = socket_status (server.sun_path);
 710     saved_errno = errno;
 711     if (sock_status && default_sock)
 712       {
 713         /* Failing that, see if LOGNAME or USER exist and differ from
 714            our euid.  If so, look for a socket based on the UID
 715            associated with the name.  This is reminiscent of the logic
 716            that init_editfns uses to set the global Vuser_full_name.  */
 717
 718         char *user_name = (char *) getenv ("LOGNAME");
 719
 720         if (!user_name)
 721           user_name = (char *) getenv ("USER");
 722
 723         if (user_name)
 724           {
 725             struct passwd *pw = getpwnam (user_name);
 726
 727             if (pw && (pw->pw_uid != geteuid ()))
 728               {
 729                 /* We're running under su, apparently. */
 730                 socket_name = alloca (100 + strlen (server_name));
 731                 sprintf (socket_name, "/tmp/emacs%d/%s",
 732                          (int) pw->pw_uid, server_name);
 733
 734                 if (strlen (socket_name) < sizeof (server.sun_path))
 735                   strcpy (server.sun_path, socket_name);
 736                 else
 737                   {
 738                     message (TRUE, "%s: socket-name %s too long",
 739                              progname, socket_name);
 740                     exit (EXIT_FAILURE);
 741                   }
 742
 743                 sock_status = socket_status (server.sun_path);
 744                 saved_errno = errno;
 745               }
 746             else
 747               errno = saved_errno;
 748           }
 749       }
 750
 751     switch (sock_status)
 752       {
 753       case 1:
 754         /* There's a socket, but it isn't owned by us.  This is OK if
 755            we are root. */
 756         if (0 != geteuid ())
 757           {
 758             message (TRUE, "%s: Invalid socket owner\n", progname);
 759             return INVALID_SOCKET;
 760           }
 761         break;
 762
 763       case 2:
 764         /* `stat' failed */
 765         if (saved_errno == ENOENT)
 766           message (TRUE,
 767                    "%s: can't find socket; have you started the server?\n\
 768 To start the server in Emacs, type \"M-x server-start\".\n",
 769                    progname);
 770         else
 771           message (TRUE, "%s: can't stat %s: %s\n",
 772                    progname, server.sun_path, strerror (saved_errno));
 773         return INVALID_SOCKET;
 774       }
 775   }
 776
 777   if (connect (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2)
 778       < 0)
 779     {
 780       message (TRUE, "%s: connect: %s\n", progname, strerror (errno));
 781       return INVALID_SOCKET;
 782     }
 783
 784   return s;
 785 }
 786 #endif /* ! NO_SOCKETS_IN_FILE_SYSTEM */
 787
 788 HSOCKET
 789 set_socket ()
 790 {
 791   HSOCKET s;
 792
 793   INITIALIZE ();
 794
 795 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 796   /* Explicit --socket-name argument.  */
 797   if (socket_name)
 798     {
 799       s = set_local_socket ();
 800       if ((s != INVALID_SOCKET) || alternate_editor)
 801         return s;
 802
 803       message (TRUE, "%s: error accessing socket \"%s\"",
 804                progname, socket_name);
 805       exit (EXIT_FAILURE);
 806     }
 807 #endif
 808
 809   /* Explicit --server-file arg or EMACS_SERVER_FILE variable.  */
 810   if (!server_file)
 811     server_file = getenv ("EMACS_SERVER_FILE");
 812
 813   if (server_file)
 814     {
 815       s = set_tcp_socket ();
 816       if ((s != INVALID_SOCKET) || alternate_editor)
 817         return s;
 818
 819       message (TRUE, "%s: error accessing server file \"%s\"",
 820                progname, server_file);
 821       exit (EXIT_FAILURE);
 822     }
 823
 824 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 825   /* Implicit local socket.  */
 826   s = set_local_socket ();
 827   if (s != INVALID_SOCKET)
 828     return s;
 829 #endif
 830
 831   /* Implicit server file.  */
 832   server_file = "server";
 833   s = set_tcp_socket ();
 834   if ((s != INVALID_SOCKET) || alternate_editor)
 835     return s;
 836
 837   /* No implicit or explicit socket, and no alternate editor.  */
 838   message (TRUE, "%s: No socket or alternate editor.  Please use:\n\n"
 839 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 840 "\t--socket-name\n"
 841 #endif
 842 "\t--server-file      (or environment variable EMACS_SERVER_FILE)\n\
 843 \t--alternate-editor (or environment variable ALTERNATE_EDITOR)\n",
 844            progname);
 845   exit (EXIT_FAILURE);
 846 }
 847
 848 #ifdef WINDOWSNT
 849 FARPROC set_fg;  /* Pointer to AllowSetForegroundWindow.  */
 850 FARPROC get_wc;  /* Pointer to RealGetWindowClassA.  */
 851
 852 BOOL CALLBACK
 853 w32_find_emacs_process (hWnd, lParam)
 854      HWND hWnd;
 855      LPARAM lParam;
 856 {
 857   DWORD pid;
 858   char class[6];
 859
 860   /* Reject any window not of class "Emacs".  */
 861   if (! get_wc (hWnd, class, sizeof (class))
 862       || strcmp (class, "Emacs"))
 863     return TRUE;
 864
 865   /* We only need the process id, not the thread id.  */
 866   (void) GetWindowThreadProcessId (hWnd, &pid);
 867
 868   /* Not the one we're looking for.  */
 869   if (pid != (DWORD) emacs_pid) return TRUE;
 870
 871   /* OK, let's raise it.  */
 872   set_fg (emacs_pid);
 873
 874   /* Stop enumeration.  */
 875   return FALSE;
 876 }
 877
 878 /*
 879  * Search for a window of class "Emacs" and owned by a process with
 880  * process id = emacs_pid.  If found, allow it to grab the focus.
 881  */
 882 void
 883 w32_give_focus ()
 884 {
 885   HMODULE hUser32;
 886
 887   /* It should'nt happen when dealing with TCP sockets.  */
 888   if (!emacs_pid) return;
 889
 890   if (!(hUser32 = LoadLibrary ("user32.dll"))) return;
 891
 892   /* Modern Windows restrict which processes can set the foreground window.
 893      emacsclient can allow Emacs to grab the focus by calling the function
 894      AllowSetForegroundWindow.  Unfortunately, older Windows (W95, W98 and
 895      NT) lack this function, so we have to check its availability.  */
 896   if ((set_fg = GetProcAddress (hUser32, "AllowSetForegroundWindow"))
 897       && (get_wc = GetProcAddress (hUser32, "RealGetWindowClassA")))
 898     EnumWindows (w32_find_emacs_process, (LPARAM) 0);
 899
 900   FreeLibrary (hUser32);
 901 }
 902 #endif
 903
 904 int
 905 main (argc, argv)
 906      int argc;
 907      char **argv;
 908 {
 909   HSOCKET s;
 910   int i, rl, needlf = 0;
 911   char *cwd;
 912   char string[BUFSIZ+1];
 913
 914   progname = argv[0];
 915
 916   /* Process options.  */
 917   decode_options (argc, argv);
 918
 919   if ((argc - optind < 1) && !eval)
 920     {
 921       message (TRUE, "%s: file name or argument required\nTry `%s --help' for more information\n",
 922               progname, progname);
 923       exit (EXIT_FAILURE);
 924     }
 925
 926   if ((s = set_socket ()) == INVALID_SOCKET)
 927     fail (argc, argv);
 928
 929 #ifdef HAVE_GETCWD
 930   cwd = getcwd (string, sizeof string);
 931 #else
 932   cwd = getwd (string);
 933 #endif
 934   if (cwd == 0)
 935     {
 936       /* getwd puts message in STRING if it fails.  */
 937       message (TRUE, "%s: %s (%s)\n", progname,
 938 #ifdef HAVE_GETCWD
 939                "Cannot get current working directory",
 940 #else
 941                string,
 942 #endif
 943                strerror (errno));
 944       fail (argc, argv);
 945     }
 946
 947 #ifdef WINDOWSNT
 948   w32_give_focus ();
 949 #endif
 950
 951   if (nowait)
 952     SEND_STRING ("-nowait ");
 953
 954   if (eval)
 955     SEND_STRING ("-eval ");
 956
 957   if (display)
 958     {
 959       SEND_STRING ("-display ");
 960       SEND_QUOTED (display);
 961       SEND_STRING (" ");
 962     }
 963
 964   if ((argc - optind > 0))
 965     {
 966       for (i = optind; i < argc; i++)
 967         {
 968           if (eval)
 969             ; /* Don't prepend any cwd or anything like that.  */
 970           else if (*argv[i] == '+')
 971             {
 972               char *p = argv[i] + 1;
 973               while (isdigit ((unsigned char) *p) || *p == ':') p++;
 974               if (*p != 0)
 975                 {
 976                   SEND_QUOTED (cwd);
 977                   SEND_STRING ("/");
 978                 }
 979             }
 980           else if (! file_name_absolute_p (argv[i]))
 981             {
 982               SEND_QUOTED (cwd);
 983               SEND_STRING ("/");
 984             }
 985
 986           SEND_QUOTED (argv[i]);
 987           SEND_STRING (" ");
 988         }
 989     }
 990   else
 991     {
 992       while (fgets (string, BUFSIZ, stdin))
 993         {
 994           SEND_QUOTED (string);
 995         }
 996       SEND_STRING (" ");
 997     }
 998
 999   SEND_STRING ("\n");
1000
1001   /* Maybe wait for an answer.   */
1002   if (!nowait)
1003     {
1004       if (!eval)
1005         {
1006           printf ("Waiting for Emacs...");
1007           needlf = 2;
1008         }
1009       fflush (stdout);
1010
1011       /* Now, wait for an answer and print any messages.  */
1012       while ((rl = recv (s, string, BUFSIZ, 0)) > 0)
1013         {
1014           string[rl] = '\0';
1015           if (needlf == 2)
1016             printf ("\n");
1017           printf ("%s", string);
1018           needlf = string[0] == '\0' ? needlf : string[strlen (string) - 1] != '\n';
1019         }
1020
1021       if (needlf)
1022         printf ("\n");
1023       fflush (stdout);
1024     }
1025
1026   CLOSE_SOCKET (s);
1027   return EXIT_SUCCESS;
1028 }
1029
1030 #endif /* HAVE_SOCKETS && HAVE_INET_SOCKETS */
1031
1032 #ifndef HAVE_STRERROR
1033 char *
1034 strerror (errnum)
1035      int errnum;
1036 {
1037   extern char *sys_errlist[];
1038   extern int sys_nerr;
1039
1040   if (errnum >= 0 && errnum < sys_nerr)
1041     return sys_errlist[errnum];
1042   return (char *) "Unknown error";
1043 }
1044
1045 #endif /* ! HAVE_STRERROR */
1046
1047 /* arch-tag: f39bb9c4-73eb-477e-896d-50832e2ca9a7
1048    (do not change this comment) */
1049
1050 /* emacsclient.c ends here */