lib-src/emacsclient.c

   1 /* Client process that communicates with GNU Emacs acting as server.
   2
   3 Copyright (C) 1986-1987, 1994, 1999-2016 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 3 of the License, or (at
  10 your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include <config.h>
  22
  23 #ifdef WINDOWSNT
  24
  25 /* ms-w32.h defines these, which disables sockets altogether!  */
  26 # undef _WINSOCKAPI_
  27 # undef _WINSOCK_H
  28
  29 # include <malloc.h>
  30 # include <stdlib.h>
  31 # include <windows.h>
  32 # include <commctrl.h>
  33 # include <io.h>
  34 # include <winsock2.h>
  35
  36 # define NO_SOCKETS_IN_FILE_SYSTEM
  37
  38 # define HSOCKET SOCKET
  39 # define CLOSE_SOCKET closesocket
  40 # define INITIALIZE() (initialize_sockets ())
  41
  42 char *w32_getenv (const char *);
  43 #define egetenv(VAR) w32_getenv(VAR)
  44
  45 #else /* !WINDOWSNT */
  46
  47 # ifdef HAVE_NTGUI
  48 # include <windows.h>
  49 # endif /* HAVE_NTGUI */
  50
  51 # include "syswait.h"
  52
  53 # ifdef HAVE_INET_SOCKETS
  54 #  include <netinet/in.h>
  55 #  ifdef HAVE_SOCKETS
  56 #    include <sys/types.h>
  57 #    include <sys/socket.h>
  58 #    include <sys/un.h>
  59 #  endif /* HAVE_SOCKETS */
  60 # endif
  61 # include <arpa/inet.h>
  62
  63 # define INVALID_SOCKET -1
  64 # define HSOCKET int
  65 # define CLOSE_SOCKET close
  66 # define INITIALIZE()
  67
  68 #define egetenv(VAR) getenv(VAR)
  69
  70 #endif /* !WINDOWSNT */
  71
  72 #undef signal
  73
  74 #include <stdarg.h>
  75 #include <ctype.h>
  76 #include <stdio.h>
  77 #include <getopt.h>
  78 #include <unistd.h>
  79
  80 #include <pwd.h>
  81 #include <sys/stat.h>
  82 #include <signal.h>
  83 #include <errno.h>
  84
  85 #ifndef VERSION
  86 #define VERSION "unspecified"
  87 #endif
  88 \f
  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 /* Additional space when allocating buffers for filenames, etc.  */
  99 #define EXTRA_SPACE 100
 100
 101 #ifdef min
 102 #undef min
 103 #endif
 104 #define min(x, y) (((x) < (y)) ? (x) : (y))
 105
 106 \f
 107 /* Name used to invoke this program.  */
 108 const char *progname;
 109
 110 /* The second argument to main.  */
 111 char **main_argv;
 112
 113 /* Nonzero means don't wait for a response from Emacs.  --no-wait.  */
 114 int nowait = 0;
 115
 116 /* Nonzero means don't print messages for successful operations.  --quiet.  */
 117 int quiet = 0;
 118
 119 /* Nonzero means args are expressions to be evaluated.  --eval.  */
 120 int eval = 0;
 121
 122 /* Nonzero means don't open a new frame.  Inverse of --create-frame.  */
 123 int current_frame = 1;
 124
 125 /* The display on which Emacs should work.  --display.  */
 126 const char *display = NULL;
 127
 128 /* The alternate display we should try if Emacs does not support display.  */
 129 const char *alt_display = NULL;
 130
 131 /* The parent window ID, if we are opening a frame via XEmbed.  */
 132 char *parent_id = NULL;
 133
 134 /* Nonzero means open a new Emacs frame on the current terminal.  */
 135 int tty = 0;
 136
 137 /* If non-NULL, the name of an editor to fallback to if the server
 138    is not running.  --alternate-editor.   */
 139 const char *alternate_editor = NULL;
 140
 141 /* If non-NULL, the filename of the UNIX socket.  */
 142 const char *socket_name = NULL;
 143
 144 /* If non-NULL, the filename of the authentication file.  */
 145 const char *server_file = NULL;
 146
 147 /* PID of the Emacs server process.  */
 148 int emacs_pid = 0;
 149
 150 /* If non-NULL, a string that should form a frame parameter alist to
 151    be used for the new frame.  */
 152 const char *frame_parameters = NULL;
 153
 154 static _Noreturn void print_help_and_exit (void);
 155
 156
 157 struct option longopts[] =
 158 {
 159   { "no-wait",  no_argument,       NULL, 'n' },
 160   { "quiet",    no_argument,       NULL, 'q' },
 161   { "eval",     no_argument,       NULL, 'e' },
 162   { "help",     no_argument,       NULL, 'H' },
 163   { "version",  no_argument,       NULL, 'V' },
 164   { "tty",      no_argument,       NULL, 't' },
 165   { "nw",       no_argument,       NULL, 't' },
 166   { "create-frame", no_argument,   NULL, 'c' },
 167   { "alternate-editor", required_argument, NULL, 'a' },
 168   { "frame-parameters", required_argument, NULL, 'F' },
 169 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 170   { "socket-name",      required_argument, NULL, 's' },
 171 #endif
 172   { "server-file",      required_argument, NULL, 'f' },
 173   { "display",  required_argument, NULL, 'd' },
 174   { "parent-id", required_argument, NULL, 'p' },
 175   { 0, 0, 0, 0 }
 176 };
 177
 178 \f
 179 /* Like malloc but get fatal error if memory is exhausted.  */
 180
 181 static void *
 182 xmalloc (size_t size)
 183 {
 184   void *result = malloc (size);
 185   if (result == NULL)
 186     {
 187       perror ("malloc");
 188       exit (EXIT_FAILURE);
 189     }
 190   return result;
 191 }
 192
 193 /* From sysdep.c */
 194 #if !defined (HAVE_GET_CURRENT_DIR_NAME) || defined (BROKEN_GET_CURRENT_DIR_NAME)
 195
 196 char *get_current_dir_name (void);
 197
 198 /* Return the current working directory.  Returns NULL on errors.
 199    Any other returned value must be freed with free.  This is used
 200    only when get_current_dir_name is not defined on the system.  */
 201 char*
 202 get_current_dir_name (void)
 203 {
 204   char *buf;
 205   const char *pwd;
 206   struct stat dotstat, pwdstat;
 207   /* If PWD is accurate, use it instead of calling getcwd.  PWD is
 208      sometimes a nicer name, and using it may avoid a fatal error if a
 209      parent directory is searchable but not readable.  */
 210     if ((pwd = egetenv ("PWD")) != 0
 211       && (IS_DIRECTORY_SEP (*pwd) || (*pwd && IS_DEVICE_SEP (pwd[1])))
 212       && stat (pwd, &pwdstat) == 0
 213       && stat (".", &dotstat) == 0
 214       && dotstat.st_ino == pwdstat.st_ino
 215       && dotstat.st_dev == pwdstat.st_dev
 216 #ifdef MAXPATHLEN
 217       && strlen (pwd) < MAXPATHLEN
 218 #endif
 219       )
 220     {
 221       buf = (char *) xmalloc (strlen (pwd) + 1);
 222       strcpy (buf, pwd);
 223     }
 224   else
 225     {
 226       size_t buf_size = 1024;
 227       for (;;)
 228         {
 229           int tmp_errno;
 230           buf = malloc (buf_size);
 231           if (! buf)
 232             break;
 233           if (getcwd (buf, buf_size) == buf)
 234             break;
 235           tmp_errno = errno;
 236           free (buf);
 237           if (tmp_errno != ERANGE)
 238             {
 239               errno = tmp_errno;
 240               return NULL;
 241             }
 242           buf_size *= 2;
 243           if (! buf_size)
 244             {
 245               errno = ENOMEM;
 246               return NULL;
 247             }
 248         }
 249     }
 250   return buf;
 251 }
 252 #endif
 253
 254 #ifdef WINDOWSNT
 255
 256 /* Like strdup but get a fatal error if memory is exhausted. */
 257 char *xstrdup (const char *);
 258
 259 char *
 260 xstrdup (const char *s)
 261 {
 262   char *result = strdup (s);
 263   if (result == NULL)
 264     {
 265       perror ("strdup");
 266       exit (EXIT_FAILURE);
 267     }
 268   return result;
 269 }
 270
 271 #define REG_ROOT "SOFTWARE\\GNU\\Emacs"
 272
 273 char *w32_get_resource (HKEY, const char *, LPDWORD);
 274
 275 /* Retrieve an environment variable from the Emacs subkeys of the registry.
 276    Return NULL if the variable was not found, or it was empty.
 277    This code is based on w32_get_resource (w32.c).  */
 278 char *
 279 w32_get_resource (HKEY predefined, const char *key, LPDWORD type)
 280 {
 281   HKEY hrootkey = NULL;
 282   char *result = NULL;
 283   DWORD cbData;
 284
 285   if (RegOpenKeyEx (predefined, REG_ROOT, 0, KEY_READ, &hrootkey) == ERROR_SUCCESS)
 286     {
 287       if (RegQueryValueEx (hrootkey, key, NULL, NULL, NULL, &cbData) == ERROR_SUCCESS)
 288         {
 289           result = (char *) xmalloc (cbData);
 290
 291           if ((RegQueryValueEx (hrootkey, key, NULL, type, (LPBYTE)result, &cbData) != ERROR_SUCCESS)
 292               || (*result == 0))
 293             {
 294               free (result);
 295               result = NULL;
 296             }
 297         }
 298
 299       RegCloseKey (hrootkey);
 300     }
 301
 302   return result;
 303 }
 304
 305 /*
 306   getenv wrapper for Windows
 307
 308   Value is allocated on the heap, and can be free'd.
 309
 310   This is needed to duplicate Emacs's behavior, which is to look for
 311   environment variables in the registry if they don't appear in the
 312   environment.  */
 313 char *
 314 w32_getenv (const char *envvar)
 315 {
 316   char *value;
 317   DWORD dwType;
 318
 319   if ((value = getenv (envvar)))
 320     /* Found in the environment.  strdup it, because values returned
 321        by getenv cannot be free'd.  */
 322     return xstrdup (value);
 323
 324   if (! (value = w32_get_resource (HKEY_CURRENT_USER, envvar, &dwType)) &&
 325       ! (value = w32_get_resource (HKEY_LOCAL_MACHINE, envvar, &dwType)))
 326     {
 327       /* "w32console" is what Emacs on Windows uses for tty-type under -nw.  */
 328       if (strcmp (envvar, "TERM") == 0)
 329         return xstrdup ("w32console");
 330       /* Found neither in the environment nor in the registry.  */
 331       return NULL;
 332     }
 333
 334   if (dwType == REG_SZ)
 335     /* Registry; no need to expand.  */
 336     return value;
 337
 338   if (dwType == REG_EXPAND_SZ)
 339     {
 340       DWORD size;
 341
 342       if ((size = ExpandEnvironmentStrings (value, NULL, 0)))
 343         {
 344           char *buffer = (char *) xmalloc (size);
 345           if (ExpandEnvironmentStrings (value, buffer, size))
 346             {
 347               /* Found and expanded.  */
 348               free (value);
 349               return buffer;
 350             }
 351
 352           /* Error expanding.  */
 353           free (buffer);
 354         }
 355     }
 356
 357   /* Not the right type, or not correctly expanded.  */
 358   free (value);
 359   return NULL;
 360 }
 361
 362 int w32_window_app (void);
 363
 364 int
 365 w32_window_app (void)
 366 {
 367   static int window_app = -1;
 368   char szTitle[MAX_PATH];
 369
 370   if (window_app < 0)
 371     {
 372       /* Checking for STDOUT does not work; it's a valid handle also in
 373          nonconsole apps.  Testing for the console title seems to work. */
 374       window_app = (GetConsoleTitleA (szTitle, MAX_PATH) == 0);
 375       if (window_app)
 376         InitCommonControls ();
 377     }
 378
 379   return window_app;
 380 }
 381
 382 /* execvp wrapper for Windows.  Quotes arguments with embedded spaces.
 383
 384   This is necessary due to the broken implementation of exec* routines in
 385   the Microsoft libraries: they concatenate the arguments together without
 386   quoting special characters, and pass the result to CreateProcess, with
 387   predictably bad results.  By contrast, POSIX execvp passes the arguments
 388   directly into the argv array of the child process.  */
 389
 390 int w32_execvp (const char *, char **);
 391
 392 int
 393 w32_execvp (const char *path, char **argv)
 394 {
 395   int i;
 396
 397   /* Required to allow a .BAT script as alternate editor.  */
 398   argv[0] = (char *) alternate_editor;
 399
 400   for (i = 0; argv[i]; i++)
 401     if (strchr (argv[i], ' '))
 402       {
 403         char *quoted = alloca (strlen (argv[i]) + 3);
 404         sprintf (quoted, "\"%s\"", argv[i]);
 405         argv[i] = quoted;
 406       }
 407
 408   return execvp (path, argv);
 409 }
 410
 411 #undef execvp
 412 #define execvp w32_execvp
 413
 414 /* Emulation of ttyname for Windows.  */
 415 const char *ttyname (int);
 416 const char *
 417 ttyname (int fd)
 418 {
 419   return "CONOUT$";
 420 }
 421
 422 #endif /* WINDOWSNT */
 423
 424 /* Display a normal or error message.
 425    On Windows, use a message box if compiled as a Windows app.  */
 426 static void message (bool, const char *, ...) ATTRIBUTE_FORMAT_PRINTF (2, 3);
 427 static void
 428 message (bool is_error, const char *format, ...)
 429 {
 430   va_list args;
 431
 432   va_start (args, format);
 433
 434 #ifdef WINDOWSNT
 435   if (w32_window_app ())
 436     {
 437       char msg[2048];
 438       vsnprintf (msg, sizeof msg, format, args);
 439       msg[sizeof msg - 1] = '\0';
 440
 441       if (is_error)
 442         MessageBox (NULL, msg, "Emacsclient ERROR", MB_ICONERROR);
 443       else
 444         MessageBox (NULL, msg, "Emacsclient", MB_ICONINFORMATION);
 445     }
 446   else
 447 #endif
 448     {
 449       FILE *f = is_error ? stderr : stdout;
 450
 451       vfprintf (f, format, args);
 452       fflush (f);
 453     }
 454
 455   va_end (args);
 456 }
 457
 458 /* Decode the options from argv and argc.
 459    The global variable `optind' will say how many arguments we used up.  */
 460
 461 static void
 462 decode_options (int argc, char **argv)
 463 {
 464   alternate_editor = egetenv ("ALTERNATE_EDITOR");
 465
 466   while (1)
 467     {
 468       int opt = getopt_long_only (argc, argv,
 469 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 470                              "VHneqa:s:f:d:F:tc",
 471 #else
 472                              "VHneqa:f:d:F:tc",
 473 #endif
 474                              longopts, 0);
 475
 476       if (opt == EOF)
 477         break;
 478
 479       switch (opt)
 480         {
 481         case 0:
 482           /* If getopt returns 0, then it has already processed a
 483              long-named option.  We should do nothing.  */
 484           break;
 485
 486         case 'a':
 487           alternate_editor = optarg;
 488           break;
 489
 490 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 491         case 's':
 492           socket_name = optarg;
 493           break;
 494 #endif
 495
 496         case 'f':
 497           server_file = optarg;
 498           break;
 499
 500           /* We used to disallow this argument in w32, but it seems better
 501              to allow it, for the occasional case where the user is
 502              connecting with a w32 client to a server compiled with X11
 503              support.  */
 504         case 'd':
 505           display = optarg;
 506           break;
 507
 508         case 'n':
 509           nowait = 1;
 510           break;
 511
 512         case 'e':
 513           eval = 1;
 514           break;
 515
 516         case 'q':
 517           quiet = 1;
 518           break;
 519
 520         case 'V':
 521           message (false, "emacsclient %s\n", VERSION);
 522           exit (EXIT_SUCCESS);
 523           break;
 524
 525         case 't':
 526           tty = 1;
 527           current_frame = 0;
 528           break;
 529
 530         case 'c':
 531           current_frame = 0;
 532           break;
 533
 534         case 'p':
 535           parent_id = optarg;
 536           current_frame = 0;
 537           break;
 538
 539         case 'H':
 540           print_help_and_exit ();
 541           break;
 542
 543         case 'F':
 544           frame_parameters = optarg;
 545           break;
 546
 547         default:
 548           message (true, "Try '%s --help' for more information\n", progname);
 549           exit (EXIT_FAILURE);
 550           break;
 551         }
 552     }
 553
 554   /* If the -c option is used (without -t) and no --display argument
 555      is provided, try $DISPLAY.
 556      Without the -c option, we used to set `display' to $DISPLAY by
 557      default, but this changed the default behavior and is sometimes
 558      inconvenient.  So we force users to use "--display $DISPLAY" if
 559      they want Emacs to connect to their current display.
 560
 561      Some window systems have a notion of default display not
 562      reflected in the DISPLAY variable.  If the user didn't give us an
 563      explicit display, try this platform-specific after trying the
 564      display in DISPLAY (if any).  */
 565   if (!current_frame && !tty && !display)
 566     {
 567       /* Set these here so we use a default_display only when the user
 568          didn't give us an explicit display.  */
 569 #if defined (NS_IMPL_COCOA)
 570       alt_display = "ns";
 571 #elif defined (HAVE_NTGUI)
 572       alt_display = "w32";
 573 #endif
 574
 575       display = egetenv ("DISPLAY");
 576     }
 577
 578   if (!display)
 579     {
 580       display = alt_display;
 581       alt_display = NULL;
 582     }
 583
 584   /* A null-string display is invalid.  */
 585   if (display && strlen (display) == 0)
 586     display = NULL;
 587
 588   /* If no display is available, new frames are tty frames.  */
 589   if (!current_frame && !display)
 590     tty = 1;
 591
 592 #ifdef WINDOWSNT
 593   /* Emacs on Windows does not support graphical and text terminal
 594      frames in the same instance.  So, treat the -t and -c options as
 595      equivalent, and open a new frame on the server's terminal.
 596      Ideally, we would only set tty = 1 when the serve is running in a
 597      console, but alas we don't know that.  As a workaround, always
 598      ask for a tty frame, and let server.el figure it out.  */
 599   if (!current_frame)
 600     {
 601       display = NULL;
 602       tty = 1;
 603     }
 604 #endif /* WINDOWSNT */
 605 }
 606
 607 \f
 608 static _Noreturn void
 609 print_help_and_exit (void)
 610 {
 611   /* Spaces and tabs are significant in this message; they're chosen so the
 612      message aligns properly both in a tty and in a Windows message box.
 613      Please try to preserve them; otherwise the output is very hard to read
 614      when using emacsclientw.  */
 615   message (false,
 616            "Usage: %s [OPTIONS] FILE...\n%s%s%s", progname, "\
 617 Tell the Emacs server to visit the specified files.\n\
 618 Every FILE can be either just a FILENAME or [+LINE[:COLUMN]] FILENAME.\n\
 619 \n\
 620 The following OPTIONS are accepted:\n\
 621 -V, --version           Just print version info and return\n\
 622 -H, --help              Print this usage information message\n\
 623 -nw, -t, --tty          Open a new Emacs frame on the current terminal\n\
 624 -c, --create-frame      Create a new frame instead of trying to\n\
 625                         use the current Emacs frame\n\
 626 ", "\
 627 -F ALIST, --frame-parameters=ALIST\n\
 628                         Set the parameters of a new frame\n\
 629 -e, --eval              Evaluate the FILE arguments as ELisp expressions\n\
 630 -n, --no-wait           Don't wait for the server to return\n\
 631 -q, --quiet             Don't display messages on success\n\
 632 -d DISPLAY, --display=DISPLAY\n\
 633                         Visit the file in the given display\n\
 634 ", "\
 635 --parent-id=ID          Open in parent window ID, via XEmbed\n"
 636 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
 637 "-s SOCKET, --socket-name=SOCKET\n\
 638                         Set filename of the UNIX socket for communication\n"
 639 #endif
 640 "-f SERVER, --server-file=SERVER\n\
 641                         Set filename of the TCP authentication file\n\
 642 -a EDITOR, --alternate-editor=EDITOR\n\
 643                         Editor to fallback to if the server is not running\n"
 644 "                       If EDITOR is the empty string, start Emacs in daemon\n\
 645                         mode and try connecting again\n"
 646 "\n\
 647 Report bugs with M-x report-emacs-bug.\n");
 648   exit (EXIT_SUCCESS);
 649 }
 650
 651 /* Try to run a different command, or --if no alternate editor is
 652    defined-- exit with an errorcode.
 653    Uses argv, but gets it from the global variable main_argv.  */
 654
 655 static _Noreturn void
 656 fail (void)
 657 {
 658   if (alternate_editor)
 659     {
 660       int i = optind - 1;
 661
 662       execvp (alternate_editor, main_argv + i);
 663       message (true, "%s: error executing alternate editor \"%s\"\n",
 664                progname, alternate_editor);
 665     }
 666   exit (EXIT_FAILURE);
 667 }
 668
 669 \f
 670 #if !defined (HAVE_SOCKETS) || !defined (HAVE_INET_SOCKETS)
 671
 672 int
 673 main (int argc, char **argv)
 674 {
 675   main_argv = argv;
 676   progname = argv[0];
 677   message (true, "%s: Sorry, the Emacs server is supported only\n"
 678            "on systems with Berkeley sockets.\n",
 679            argv[0]);
 680   fail ();
 681 }
 682
 683 #else /* HAVE_SOCKETS && HAVE_INET_SOCKETS */
 684
 685 #define AUTH_KEY_LENGTH      64
 686 #define SEND_BUFFER_SIZE   4096
 687
 688 /* Buffer to accumulate data to send in TCP connections.  */
 689 char send_buffer[SEND_BUFFER_SIZE + 1];
 690 int sblen = 0;  /* Fill pointer for the send buffer.  */
 691 /* Socket used to communicate with the Emacs server process.  */
 692 HSOCKET emacs_socket = 0;
 693
 694 /* On Windows, the socket library was historically separate from the
 695    standard C library, so errors are handled differently.  */
 696
 697 static void
 698 sock_err_message (const char *function_name)
 699 {
 700 #ifdef WINDOWSNT
 701   char* msg = NULL;
 702
 703   FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
 704                  | FORMAT_MESSAGE_ALLOCATE_BUFFER
 705                  | FORMAT_MESSAGE_ARGUMENT_ARRAY,
 706                  NULL, WSAGetLastError (), 0, (LPTSTR)&msg, 0, NULL);
 707
 708   message (true, "%s: %s: %s\n", progname, function_name, msg);
 709
 710   LocalFree (msg);
 711 #else
 712   message (true, "%s: %s: %s\n", progname, function_name, strerror (errno));
 713 #endif
 714 }
 715
 716
 717 /* Let's send the data to Emacs when either
 718    - the data ends in "\n", or
 719    - the buffer is full (but this shouldn't happen)
 720    Otherwise, we just accumulate it.  */
 721 static void
 722 send_to_emacs (HSOCKET s, const char *data)
 723 {
 724   size_t dlen;
 725
 726   if (!data)
 727     return;
 728
 729   dlen = strlen (data);
 730   while (*data)
 731     {
 732       size_t part = min (dlen, SEND_BUFFER_SIZE - sblen);
 733       memcpy (&send_buffer[sblen], data, part);
 734       data += part;
 735       sblen += part;
 736
 737       if (sblen == SEND_BUFFER_SIZE
 738           || (sblen > 0 && send_buffer[sblen-1] == '\n'))
 739         {
 740           int sent = send (s, send_buffer, sblen, 0);
 741           if (sent < 0)
 742             {
 743               message (true, "%s: failed to send %d bytes to socket: %s\n",
 744                        progname, sblen, strerror (errno));
 745               fail ();
 746             }
 747           if (sent != sblen)
 748             memmove (send_buffer, &send_buffer[sent], sblen - sent);
 749           sblen -= sent;
 750         }
 751
 752       dlen -= part;
 753     }
 754 }
 755
 756 \f
 757 /* In STR, insert a & before each &, each space, each newline, and
 758    any initial -.  Change spaces to underscores, too, so that the
 759    return value never contains a space.
 760
 761    Does not change the string.  Outputs the result to S.  */
 762 static void
 763 quote_argument (HSOCKET s, const char *str)
 764 {
 765   char *copy = (char *) xmalloc (strlen (str) * 2 + 1);
 766   const char *p;
 767   char *q;
 768
 769   p = str;
 770   q = copy;
 771   while (*p)
 772     {
 773       if (*p == ' ')
 774         {
 775           *q++ = '&';
 776           *q++ = '_';
 777           p++;
 778         }
 779       else if (*p == '\n')
 780         {
 781           *q++ = '&';
 782           *q++ = 'n';
 783           p++;
 784         }
 785       else
 786         {
 787           if (*p == '&' || (*p == '-' && p == str))
 788             *q++ = '&';
 789           *q++ = *p++;
 790         }
 791     }
 792   *q++ = 0;
 793
 794   send_to_emacs (s, copy);
 795
 796   free (copy);
 797 }
 798
 799
 800 /* The inverse of quote_argument.  Removes quoting in string STR by
 801    modifying the string in place.   Returns STR.  */
 802
 803 static char *
 804 unquote_argument (char *str)
 805 {
 806   char *p, *q;
 807
 808   if (! str)
 809     return str;
 810
 811   p = str;
 812   q = str;
 813   while (*p)
 814     {
 815       if (*p == '&')
 816         {
 817           p++;
 818           if (*p == '&')
 819             *p = '&';
 820           else if (*p == '_')
 821             *p = ' ';
 822           else if (*p == 'n')
 823             *p = '\n';
 824           else if (*p == '-')
 825             *p = '-';
 826         }
 827       *q++ = *p++;
 828     }
 829   *q = 0;
 830   return str;
 831 }
 832
 833 \f
 834 static int
 835 file_name_absolute_p (const char *filename)
 836 {
 837   /* Sanity check, it shouldn't happen.  */
 838   if (! filename) return false;
 839
 840   /* /xxx is always an absolute path.  */
 841   if (filename[0] == '/') return true;
 842
 843   /* Empty filenames (which shouldn't happen) are relative.  */
 844   if (filename[0] == '\0') return false;
 845
 846 #ifdef WINDOWSNT
 847   /* X:\xxx is always absolute.  */
 848   if (isalpha ((unsigned char) filename[0])
 849       && filename[1] == ':' && (filename[2] == '\\' || filename[2] == '/'))
 850     return true;
 851
 852   /* Both \xxx and \\xxx\yyy are absolute.  */
 853   if (filename[0] == '\\') return true;
 854 #endif
 855
 856   return false;
 857 }
 858
 859 #ifdef WINDOWSNT
 860 /* Wrapper to make WSACleanup a cdecl, as required by atexit.  */
 861 void __cdecl close_winsock (void);
 862 void __cdecl
 863 close_winsock (void)
 864 {
 865   WSACleanup ();
 866 }
 867
 868 /* Initialize the WinSock2 library.  */
 869 void initialize_sockets (void);
 870 void
 871 initialize_sockets (void)
 872 {
 873   WSADATA wsaData;
 874
 875   if (WSAStartup (MAKEWORD (2, 0), &wsaData))
 876     {
 877       message (true, "%s: error initializing WinSock2\n", progname);
 878       exit (EXIT_FAILURE);
 879     }
 880
 881   atexit (close_winsock);
 882 }
 883 #endif /* WINDOWSNT */
 884
 885 \f
 886 /* Read the information needed to set up a TCP comm channel with
 887    the Emacs server: host, port, and authentication string.  */
 888
 889 static int
 890 get_server_config (const char *config_file, struct sockaddr_in *server,
 891                    char *authentication)
 892 {
 893   char dotted[32];
 894   char *port;
 895   FILE *config = NULL;
 896
 897   if (file_name_absolute_p (config_file))
 898     config = fopen (config_file, "rb");
 899   else
 900     {
 901       const char *home = egetenv ("HOME");
 902
 903       if (home)
 904         {
 905           char *path = xmalloc (strlen (home) + strlen (config_file)
 906                                 + EXTRA_SPACE);
 907           char *z = stpcpy (path, home);
 908           z = stpcpy (z, "/.emacs.d/server/");
 909           strcpy (z, config_file);
 910           config = fopen (path, "rb");
 911           free (path);
 912         }
 913 #ifdef WINDOWSNT
 914       if (!config && (home = egetenv ("APPDATA")))
 915         {
 916           char *path = xmalloc (strlen (home) + strlen (config_file)
 917                                 + EXTRA_SPACE);
 918           char *z = stpcpy (path, home);
 919           z = stpcpy (z, "/.emacs.d/server/");
 920           strcpy (z, config_file);
 921           config = fopen (path, "rb");
 922           free (path);
 923         }
 924 #endif
 925     }
 926
 927   if (! config)
 928     return false;
 929
 930   if (fgets (dotted, sizeof dotted, config)
 931       && (port = strchr (dotted, ':')))
 932     *port++ = '\0';
 933   else
 934     {
 935       message (true, "%s: invalid configuration info\n", progname);
 936       exit (EXIT_FAILURE);
 937     }
 938
 939   server->sin_family = AF_INET;
 940   server->sin_addr.s_addr = inet_addr (dotted);
 941   server->sin_port = htons (atoi (port));
 942
 943   if (! fread (authentication, AUTH_KEY_LENGTH, 1, config))
 944     {
 945       message (true, "%s: cannot read authentication info\n", progname);
 946       exit (EXIT_FAILURE);
 947     }
 948
 949   fclose (config);
 950
 951   return true;
 952 }
 953
 954 static HSOCKET
 955 set_tcp_socket (const char *local_server_file)
 956 {
 957   HSOCKET s;
 958   struct sockaddr_in server;
 959   struct linger l_arg = {1, 1};
 960   char auth_string[AUTH_KEY_LENGTH + 1];
 961
 962   if (! get_server_config (local_server_file, &server, auth_string))
 963     return INVALID_SOCKET;
 964
 965   if (server.sin_addr.s_addr != inet_addr ("127.0.0.1") && !quiet)
 966     message (false, "%s: connected to remote socket at %s\n",
 967              progname, inet_ntoa (server.sin_addr));
 968
 969   /* Open up an AF_INET socket.  */
 970   if ((s = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
 971     {
 972       /* Since we have an alternate to try out, this is not an error
 973          yet; popping out a modal dialog at this stage would make -a
 974          option totally useless for emacsclientw -- the user will
 975          still get an error message if the alternate editor fails.  */
 976 #ifdef WINDOWSNT
 977       if(!(w32_window_app () && alternate_editor))
 978 #endif
 979       sock_err_message ("socket");
 980       return INVALID_SOCKET;
 981     }
 982
 983   /* Set up the socket.  */
 984   if (connect (s, (struct sockaddr *) &server, sizeof server) < 0)
 985     {
 986 #ifdef WINDOWSNT
 987       if(!(w32_window_app () && alternate_editor))
 988 #endif
 989       sock_err_message ("connect");
 990       return INVALID_SOCKET;
 991     }
 992
 993   setsockopt (s, SOL_SOCKET, SO_LINGER, (char *) &l_arg, sizeof l_arg);
 994
 995   /* Send the authentication.  */
 996   auth_string[AUTH_KEY_LENGTH] = '\0';
 997
 998   send_to_emacs (s, "-auth ");
 999   send_to_emacs (s, auth_string);
1000   send_to_emacs (s, " ");
1001
1002   return s;
1003 }
1004
1005
1006 /* Returns 1 if PREFIX is a prefix of STRING. */
1007 static int
1008 strprefix (const char *prefix, const char *string)
1009 {
1010   return !strncmp (prefix, string, strlen (prefix));
1011 }
1012
1013 /* Get tty name and type.  If successful, return the type in TTY_TYPE
1014    and the name in TTY_NAME, and return 1.  Otherwise, fail if NOABORT
1015    is zero, or return 0 if NOABORT is non-zero.  */
1016
1017 static int
1018 find_tty (const char **tty_type, const char **tty_name, int noabort)
1019 {
1020   const char *type = egetenv ("TERM");
1021   const char *name = ttyname (fileno (stdout));
1022
1023   if (!name)
1024     {
1025       if (noabort)
1026         return 0;
1027       else
1028         {
1029           message (true, "%s: could not get terminal name\n", progname);
1030           fail ();
1031         }
1032     }
1033
1034   if (!type)
1035     {
1036       if (noabort)
1037         return 0;
1038       else
1039         {
1040           message (true, "%s: please set the TERM variable to your terminal type\n",
1041                    progname);
1042           fail ();
1043         }
1044     }
1045
1046   if (strcmp (type, "eterm") == 0)
1047     {
1048       if (noabort)
1049         return 0;
1050       else
1051         {
1052           /* This causes nasty, MULTI_KBOARD-related input lockouts. */
1053           message (true, "%s: opening a frame in an Emacs term buffer"
1054                    " is not supported\n", progname);
1055           fail ();
1056         }
1057     }
1058
1059   *tty_name = name;
1060   *tty_type = type;
1061   return 1;
1062 }
1063
1064
1065 #if !defined (NO_SOCKETS_IN_FILE_SYSTEM)
1066
1067 /* Three possibilities:
1068    2 - can't be `stat'ed                (sets errno)
1069    1 - isn't owned by us
1070    0 - success: none of the above */
1071
1072 static int
1073 socket_status (const char *name)
1074 {
1075   struct stat statbfr;
1076
1077   if (stat (name, &statbfr) == -1)
1078     return 2;
1079
1080   if (statbfr.st_uid != geteuid ())
1081     return 1;
1082
1083   return 0;
1084 }
1085
1086 \f
1087 /* A signal handler that passes the signal to the Emacs process.
1088    Useful for SIGWINCH.  */
1089
1090 static void
1091 pass_signal_to_emacs (int signalnum)
1092 {
1093   int old_errno = errno;
1094
1095   if (emacs_pid)
1096     kill (emacs_pid, signalnum);
1097
1098   signal (signalnum, pass_signal_to_emacs);
1099   errno = old_errno;
1100 }
1101
1102 /* Signal handler for SIGCONT; notify the Emacs process that it can
1103    now resume our tty frame.  */
1104
1105 static void
1106 handle_sigcont (int signalnum)
1107 {
1108   int old_errno = errno;
1109   pid_t pgrp = getpgrp ();
1110   pid_t tcpgrp = tcgetpgrp (1);
1111
1112   if (tcpgrp == pgrp)
1113     {
1114       /* We are in the foreground.  */
1115       send_to_emacs (emacs_socket, "-resume \n");
1116     }
1117   else if (0 <= tcpgrp && tty)
1118     {
1119       /* We are in the background; cancel the continue.  */
1120       kill (-pgrp, SIGTTIN);
1121     }
1122
1123   signal (signalnum, handle_sigcont);
1124   errno = old_errno;
1125 }
1126
1127 /* Signal handler for SIGTSTP; notify the Emacs process that we are
1128    going to sleep.  Normally the suspend is initiated by Emacs via
1129    server-handle-suspend-tty, but if the server gets out of sync with
1130    reality, we may get a SIGTSTP on C-z.  Handling this signal and
1131    notifying Emacs about it should get things under control again.  */
1132
1133 static void
1134 handle_sigtstp (int signalnum)
1135 {
1136   int old_errno = errno;
1137   sigset_t set;
1138
1139   if (emacs_socket)
1140     send_to_emacs (emacs_socket, "-suspend \n");
1141
1142   /* Unblock this signal and call the default handler by temporarily
1143      changing the handler and resignaling.  */
1144   sigprocmask (SIG_BLOCK, NULL, &set);
1145   sigdelset (&set, signalnum);
1146   signal (signalnum, SIG_DFL);
1147   raise (signalnum);
1148   sigprocmask (SIG_SETMASK, &set, NULL); /* Let's the above signal through. */
1149   signal (signalnum, handle_sigtstp);
1150
1151   errno = old_errno;
1152 }
1153
1154
1155 /* Set up signal handlers before opening a frame on the current tty.  */
1156
1157 static void
1158 init_signals (void)
1159 {
1160   /* Set up signal handlers. */
1161   signal (SIGWINCH, pass_signal_to_emacs);
1162
1163   /* Don't pass SIGINT and SIGQUIT to Emacs, because it has no way of
1164      deciding which terminal the signal came from.  C-g is now a
1165      normal input event on secondary terminals.  */
1166 #if 0
1167   signal (SIGINT, pass_signal_to_emacs);
1168   signal (SIGQUIT, pass_signal_to_emacs);
1169 #endif
1170
1171   signal (SIGCONT, handle_sigcont);
1172   signal (SIGTSTP, handle_sigtstp);
1173   signal (SIGTTOU, handle_sigtstp);
1174 }
1175
1176
1177 static HSOCKET
1178 set_local_socket (const char *local_socket_name)
1179 {
1180   HSOCKET s;
1181   struct sockaddr_un server;
1182
1183   /* Open up an AF_UNIX socket in this person's home directory.  */
1184   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
1185     {
1186       message (true, "%s: socket: %s\n", progname, strerror (errno));
1187       return INVALID_SOCKET;
1188     }
1189
1190   server.sun_family = AF_UNIX;
1191
1192   {
1193     int sock_status;
1194     int use_tmpdir = 0;
1195     int saved_errno;
1196     const char *server_name = local_socket_name;
1197     const char *tmpdir;
1198     char *tmpdir_storage = NULL;
1199     char *socket_name_storage = NULL;
1200
1201     if (!strchr (local_socket_name, '/') && !strchr (local_socket_name, '\\'))
1202       {
1203         /* socket_name is a file name component.  */
1204         long uid = geteuid ();
1205         use_tmpdir = 1;
1206         tmpdir = egetenv ("TMPDIR");
1207         if (!tmpdir)
1208           {
1209 #ifdef DARWIN_OS
1210 #ifndef _CS_DARWIN_USER_TEMP_DIR
1211 #define _CS_DARWIN_USER_TEMP_DIR 65537
1212 #endif
1213             size_t n = confstr (_CS_DARWIN_USER_TEMP_DIR, NULL, (size_t) 0);
1214             if (n > 0)
1215               {
1216                 tmpdir = tmpdir_storage = xmalloc (n);
1217                 confstr (_CS_DARWIN_USER_TEMP_DIR, tmpdir_storage, n);
1218               }
1219             else
1220 #endif
1221               tmpdir = "/tmp";
1222           }
1223         socket_name_storage =
1224           xmalloc (strlen (tmpdir) + strlen (server_name) + EXTRA_SPACE);
1225         char *z = stpcpy (socket_name_storage, tmpdir);
1226         z += sprintf (z, "/emacs%ld/", uid);
1227         strcpy (z, server_name);
1228         local_socket_name = socket_name_storage;
1229       }
1230
1231     if (strlen (local_socket_name) < sizeof (server.sun_path))
1232       strcpy (server.sun_path, local_socket_name);
1233     else
1234       {
1235         message (true, "%s: socket-name %s too long\n",
1236                  progname, local_socket_name);
1237         fail ();
1238       }
1239
1240     /* See if the socket exists, and if it's owned by us. */
1241     sock_status = socket_status (server.sun_path);
1242     saved_errno = errno;
1243     if (sock_status && use_tmpdir)
1244       {
1245         /* Failing that, see if LOGNAME or USER exist and differ from
1246            our euid.  If so, look for a socket based on the UID
1247            associated with the name.  This is reminiscent of the logic
1248            that init_editfns uses to set the global Vuser_full_name.  */
1249
1250         const char *user_name = egetenv ("LOGNAME");
1251
1252         if (!user_name)
1253           user_name = egetenv ("USER");
1254
1255         if (user_name)
1256           {
1257             struct passwd *pw = getpwnam (user_name);
1258
1259             if (pw && (pw->pw_uid != geteuid ()))
1260               {
1261                 /* We're running under su, apparently. */
1262                 long uid = pw->pw_uid;
1263                 char *user_socket_name
1264                   = xmalloc (strlen (tmpdir) + strlen (server_name)
1265                              + EXTRA_SPACE);
1266                 char *z = stpcpy (user_socket_name, tmpdir);
1267                 z += sprintf (z, "/emacs%ld/", uid);
1268                 strcpy (z, server_name);
1269
1270                 if (strlen (user_socket_name) < sizeof (server.sun_path))
1271                   strcpy (server.sun_path, user_socket_name);
1272                 else
1273                   {
1274                     message (true, "%s: socket-name %s too long\n",
1275                              progname, user_socket_name);
1276                     exit (EXIT_FAILURE);
1277                   }
1278                 free (user_socket_name);
1279
1280                 sock_status = socket_status (server.sun_path);
1281                 saved_errno = errno;
1282               }
1283             else
1284               errno = saved_errno;
1285           }
1286       }
1287
1288     free (socket_name_storage);
1289     free (tmpdir_storage);
1290
1291     switch (sock_status)
1292       {
1293       case 1:
1294         /* There's a socket, but it isn't owned by us.  This is OK if
1295            we are root. */
1296         if (0 != geteuid ())
1297           {
1298             message (true, "%s: Invalid socket owner\n", progname);
1299             return INVALID_SOCKET;
1300           }
1301         break;
1302
1303       case 2:
1304         /* `stat' failed */
1305         if (saved_errno == ENOENT)
1306           message (true,
1307                    "%s: can't find socket; have you started the server?\n\
1308 To start the server in Emacs, type \"M-x server-start\".\n",
1309                    progname);
1310         else
1311           message (true, "%s: can't stat %s: %s\n",
1312                    progname, server.sun_path, strerror (saved_errno));
1313         return INVALID_SOCKET;
1314       }
1315   }
1316
1317   if (connect (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2)
1318       < 0)
1319     {
1320       message (true, "%s: connect: %s\n", progname, strerror (errno));
1321       return INVALID_SOCKET;
1322     }
1323
1324   return s;
1325 }
1326 #endif /* ! NO_SOCKETS_IN_FILE_SYSTEM */
1327
1328 static HSOCKET
1329 set_socket (int no_exit_if_error)
1330 {
1331   HSOCKET s;
1332   const char *local_server_file = server_file;
1333
1334   INITIALIZE ();
1335
1336 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
1337   /* Explicit --socket-name argument.  */
1338   if (socket_name)
1339     {
1340       s = set_local_socket (socket_name);
1341       if ((s != INVALID_SOCKET) || no_exit_if_error)
1342         return s;
1343       message (true, "%s: error accessing socket \"%s\"\n",
1344                progname, socket_name);
1345       exit (EXIT_FAILURE);
1346     }
1347 #endif
1348
1349   /* Explicit --server-file arg or EMACS_SERVER_FILE variable.  */
1350   if (!local_server_file)
1351     local_server_file = egetenv ("EMACS_SERVER_FILE");
1352
1353   if (local_server_file)
1354     {
1355       s = set_tcp_socket (local_server_file);
1356       if ((s != INVALID_SOCKET) || no_exit_if_error)
1357         return s;
1358
1359       message (true, "%s: error accessing server file \"%s\"\n",
1360                progname, local_server_file);
1361       exit (EXIT_FAILURE);
1362     }
1363
1364 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
1365   /* Implicit local socket.  */
1366   s = set_local_socket ("server");
1367   if (s != INVALID_SOCKET)
1368     return s;
1369 #endif
1370
1371   /* Implicit server file.  */
1372   s = set_tcp_socket ("server");
1373   if ((s != INVALID_SOCKET) || no_exit_if_error)
1374     return s;
1375
1376   /* No implicit or explicit socket, and no alternate editor.  */
1377   message (true, "%s: No socket or alternate editor.  Please use:\n\n"
1378 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
1379 "\t--socket-name\n"
1380 #endif
1381 "\t--server-file      (or environment variable EMACS_SERVER_FILE)\n\
1382 \t--alternate-editor (or environment variable ALTERNATE_EDITOR)\n",
1383            progname);
1384   exit (EXIT_FAILURE);
1385 }
1386
1387 #ifdef HAVE_NTGUI
1388 FARPROC set_fg;  /* Pointer to AllowSetForegroundWindow.  */
1389 FARPROC get_wc;  /* Pointer to RealGetWindowClassA.  */
1390
1391 void w32_set_user_model_id (void);
1392
1393 void
1394 w32_set_user_model_id (void)
1395 {
1396   HMODULE shell;
1397   HRESULT (WINAPI * set_user_model) (const wchar_t * id);
1398
1399   /* On Windows 7 and later, we need to set the user model ID
1400      to associate emacsclient launched files with Emacs frames
1401      in the UI.  */
1402   shell = LoadLibrary ("shell32.dll");
1403   if (shell)
1404     {
1405       set_user_model
1406         = (void *) GetProcAddress (shell,
1407                                    "SetCurrentProcessExplicitAppUserModelID");
1408       /* If the function is defined, then we are running on Windows 7
1409          or newer, and the UI uses this to group related windows
1410          together.  Since emacs, runemacs, emacsclient are related, we
1411          want them grouped even though the executables are different,
1412          so we need to set a consistent ID between them.  */
1413       if (set_user_model)
1414         set_user_model (L"GNU.Emacs");
1415
1416       FreeLibrary (shell);
1417     }
1418 }
1419
1420 BOOL CALLBACK w32_find_emacs_process (HWND, LPARAM);
1421
1422 BOOL CALLBACK
1423 w32_find_emacs_process (HWND hWnd, LPARAM lParam)
1424 {
1425   DWORD pid;
1426   char class[6];
1427
1428   /* Reject any window not of class "Emacs".  */
1429   if (! get_wc (hWnd, class, sizeof (class))
1430       || strcmp (class, "Emacs"))
1431     return TRUE;
1432
1433   /* We only need the process id, not the thread id.  */
1434   (void) GetWindowThreadProcessId (hWnd, &pid);
1435
1436   /* Not the one we're looking for.  */
1437   if (pid != (DWORD) emacs_pid) return TRUE;
1438
1439   /* OK, let's raise it.  */
1440   set_fg (emacs_pid);
1441
1442   /* Stop enumeration.  */
1443   return FALSE;
1444 }
1445
1446 /* Search for a window of class "Emacs" and owned by a process with
1447    process id = emacs_pid.  If found, allow it to grab the focus.  */
1448 void w32_give_focus (void);
1449
1450 void
1451 w32_give_focus (void)
1452 {
1453   HANDLE user32;
1454
1455   /* It shouldn't happen when dealing with TCP sockets.  */
1456   if (!emacs_pid) return;
1457
1458   user32 = GetModuleHandle ("user32.dll");
1459
1460   if (!user32)
1461     return;
1462
1463   /* Modern Windows restrict which processes can set the foreground window.
1464      emacsclient can allow Emacs to grab the focus by calling the function
1465      AllowSetForegroundWindow.  Unfortunately, older Windows (W95, W98 and
1466      NT) lack this function, so we have to check its availability.  */
1467   if ((set_fg = GetProcAddress (user32, "AllowSetForegroundWindow"))
1468       && (get_wc = GetProcAddress (user32, "RealGetWindowClassA")))
1469     EnumWindows (w32_find_emacs_process, (LPARAM) 0);
1470 }
1471 #endif /* HAVE_NTGUI */
1472
1473 /* Start the emacs daemon and try to connect to it.  */
1474
1475 static void
1476 start_daemon_and_retry_set_socket (void)
1477 {
1478 #ifndef WINDOWSNT
1479   pid_t dpid;
1480   int status;
1481
1482   dpid = fork ();
1483
1484   if (dpid > 0)
1485     {
1486       pid_t w;
1487       w = waitpid (dpid, &status, WUNTRACED | WCONTINUED);
1488
1489       if ((w == -1) || !WIFEXITED (status) || WEXITSTATUS (status))
1490         {
1491           message (true, "Error: Could not start the Emacs daemon\n");
1492           exit (EXIT_FAILURE);
1493         }
1494
1495       /* Try connecting, the daemon should have started by now.  */
1496       message (true, "Emacs daemon should have started, trying to connect again\n");
1497       if ((emacs_socket = set_socket (1)) == INVALID_SOCKET)
1498         {
1499           message (true, "Error: Cannot connect even after starting the Emacs daemon\n");
1500           exit (EXIT_FAILURE);
1501         }
1502     }
1503   else if (dpid < 0)
1504     {
1505       fprintf (stderr, "Error: Cannot fork!\n");
1506       exit (EXIT_FAILURE);
1507     }
1508   else
1509     {
1510       char emacs[] = "emacs";
1511       char daemon_option[] = "--daemon";
1512       char *d_argv[3];
1513       d_argv[0] = emacs;
1514       d_argv[1] = daemon_option;
1515       d_argv[2] = 0;
1516       if (socket_name != NULL)
1517         {
1518           /* Pass  --daemon=socket_name as argument.  */
1519           const char *deq = "--daemon=";
1520           char *daemon_arg = xmalloc (strlen (deq)
1521                                       + strlen (socket_name) + 1);
1522           strcpy (stpcpy (daemon_arg, deq), socket_name);
1523           d_argv[1] = daemon_arg;
1524         }
1525       execvp ("emacs", d_argv);
1526       message (true, "%s: error starting emacs daemon\n", progname);
1527     }
1528 #else  /* WINDOWSNT */
1529   DWORD wait_result;
1530   HANDLE w32_daemon_event;
1531   STARTUPINFO si;
1532   PROCESS_INFORMATION pi;
1533
1534   ZeroMemory (&si, sizeof si);
1535   si.cb = sizeof si;
1536   ZeroMemory (&pi, sizeof pi);
1537
1538   /* We start Emacs in daemon mode, and then wait for it to signal us
1539      it is ready to accept client connections, by asserting an event
1540      whose name is known to the daemon (defined by nt/inc/ms-w32.h).  */
1541
1542   if (!CreateProcess (NULL, (LPSTR)"emacs --daemon", NULL, NULL, FALSE,
1543                       CREATE_NO_WINDOW, NULL, NULL, &si, &pi))
1544     {
1545       char* msg = NULL;
1546
1547       FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
1548                      | FORMAT_MESSAGE_ALLOCATE_BUFFER
1549                      | FORMAT_MESSAGE_ARGUMENT_ARRAY,
1550                      NULL, GetLastError (), 0, (LPTSTR)&msg, 0, NULL);
1551       message (true, "%s: error starting emacs daemon (%s)\n", progname, msg);
1552       exit (EXIT_FAILURE);
1553     }
1554
1555   w32_daemon_event = CreateEvent (NULL, TRUE, FALSE, W32_DAEMON_EVENT);
1556   if (w32_daemon_event == NULL)
1557     {
1558       message (true, "Couldn't create Windows daemon event");
1559       exit (EXIT_FAILURE);
1560     }
1561   if ((wait_result = WaitForSingleObject (w32_daemon_event, INFINITE))
1562       != WAIT_OBJECT_0)
1563     {
1564       const char *msg = NULL;
1565
1566       switch (wait_result)
1567         {
1568         case WAIT_ABANDONED:
1569           msg = "The daemon exited unexpectedly";
1570           break;
1571         case WAIT_TIMEOUT:
1572           /* Can't happen due to INFINITE.  */
1573         default:
1574         case WAIT_FAILED:
1575           FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
1576                          | FORMAT_MESSAGE_ALLOCATE_BUFFER
1577                          | FORMAT_MESSAGE_ARGUMENT_ARRAY,
1578                          NULL, GetLastError (), 0, (LPTSTR)&msg, 0, NULL);
1579           break;
1580         }
1581       message (true, "Error: Could not start the Emacs daemon: %s\n", msg);
1582       exit (EXIT_FAILURE);
1583     }
1584   CloseHandle (w32_daemon_event);
1585
1586   /* Try connecting, the daemon should have started by now.  */
1587   /* It's just a progress message, so don't pop a dialog if this is
1588      emacsclientw.  */
1589   if (!w32_window_app ())
1590     message (true,
1591              "Emacs daemon should have started, trying to connect again\n");
1592   if ((emacs_socket = set_socket (1)) == INVALID_SOCKET)
1593     {
1594       message (true,
1595                "Error: Cannot connect even after starting the Emacs daemon\n");
1596       exit (EXIT_FAILURE);
1597     }
1598 #endif  /* WINDOWSNT */
1599 }
1600
1601 int
1602 main (int argc, char **argv)
1603 {
1604   int rl = 0, needlf = 0;
1605   char *cwd, *str;
1606   char string[BUFSIZ+1];
1607   int start_daemon_if_needed;
1608   int exit_status = EXIT_SUCCESS;
1609
1610   main_argv = argv;
1611   progname = argv[0];
1612
1613 #ifdef HAVE_NTGUI
1614   /* On Windows 7 and later, we need to explicitly associate
1615      emacsclient with emacs so the UI behaves sensibly.  This
1616      association does no harm if we're not actually connecting to an
1617      Emacs using a window display.  */
1618   w32_set_user_model_id ();
1619 #endif /* HAVE_NTGUI */
1620
1621   /* Process options.  */
1622   decode_options (argc, argv);
1623
1624   if ((argc - optind < 1) && !eval && current_frame)
1625     {
1626       message (true, "%s: file name or argument required\n"
1627                "Try '%s --help' for more information\n",
1628                progname, progname);
1629       exit (EXIT_FAILURE);
1630     }
1631
1632 #ifndef WINDOWSNT
1633   if (tty)
1634     {
1635       pid_t pgrp = getpgrp ();
1636       pid_t tcpgrp = tcgetpgrp (1);
1637       if (0 <= tcpgrp && tcpgrp != pgrp)
1638         kill (-pgrp, SIGTTIN);
1639     }
1640 #endif /* !WINDOWSNT */
1641
1642   /* If alternate_editor is the empty string, start the emacs daemon
1643      in case of failure to connect.  */
1644   start_daemon_if_needed = (alternate_editor
1645                             && (alternate_editor[0] == '\0'));
1646
1647   emacs_socket = set_socket (alternate_editor || start_daemon_if_needed);
1648   if (emacs_socket == INVALID_SOCKET)
1649     {
1650       if (! start_daemon_if_needed)
1651         fail ();
1652
1653       start_daemon_and_retry_set_socket ();
1654     }
1655
1656   cwd = get_current_dir_name ();
1657   if (cwd == 0)
1658     {
1659       message (true, "%s: %s\n", progname,
1660                "Cannot get current working directory");
1661       fail ();
1662     }
1663
1664 #ifdef HAVE_NTGUI
1665   if (display && !strcmp (display, "w32"))
1666   w32_give_focus ();
1667 #endif /* HAVE_NTGUI */
1668
1669   /* Send over our environment and current directory. */
1670   if (!current_frame)
1671     {
1672       int i;
1673       for (i = 0; environ[i]; i++)
1674         {
1675           send_to_emacs (emacs_socket, "-env ");
1676           quote_argument (emacs_socket, environ[i]);
1677           send_to_emacs (emacs_socket, " ");
1678         }
1679     }
1680   send_to_emacs (emacs_socket, "-dir ");
1681   quote_argument (emacs_socket, cwd);
1682   send_to_emacs (emacs_socket, "/");
1683   send_to_emacs (emacs_socket, " ");
1684
1685  retry:
1686   if (nowait)
1687     send_to_emacs (emacs_socket, "-nowait ");
1688
1689   if (current_frame)
1690     send_to_emacs (emacs_socket, "-current-frame ");
1691
1692   if (display)
1693     {
1694       send_to_emacs (emacs_socket, "-display ");
1695       quote_argument (emacs_socket, display);
1696       send_to_emacs (emacs_socket, " ");
1697     }
1698
1699   if (parent_id)
1700     {
1701       send_to_emacs (emacs_socket, "-parent-id ");
1702       quote_argument (emacs_socket, parent_id);
1703       send_to_emacs (emacs_socket, " ");
1704     }
1705
1706   if (frame_parameters && !current_frame)
1707     {
1708       send_to_emacs (emacs_socket, "-frame-parameters ");
1709       quote_argument (emacs_socket, frame_parameters);
1710       send_to_emacs (emacs_socket, " ");
1711     }
1712
1713   /* Unless we are certain we don't want to occupy the tty, send our
1714      tty information to Emacs.  For example, in daemon mode Emacs may
1715      need to occupy this tty if no other frame is available.  */
1716   if (!current_frame || !eval)
1717     {
1718       const char *tty_type, *tty_name;
1719
1720       if (find_tty (&tty_type, &tty_name, !tty))
1721         {
1722 #if !defined (NO_SOCKETS_IN_FILE_SYSTEM)
1723           init_signals ();
1724 #endif
1725           send_to_emacs (emacs_socket, "-tty ");
1726           quote_argument (emacs_socket, tty_name);
1727           send_to_emacs (emacs_socket, " ");
1728           quote_argument (emacs_socket, tty_type);
1729           send_to_emacs (emacs_socket, " ");
1730         }
1731     }
1732
1733   if (!current_frame && !tty)
1734     send_to_emacs (emacs_socket, "-window-system ");
1735
1736   if ((argc - optind > 0))
1737     {
1738       int i;
1739       for (i = optind; i < argc; i++)
1740         {
1741
1742           if (eval)
1743             {
1744               /* Don't prepend cwd or anything like that.  */
1745               send_to_emacs (emacs_socket, "-eval ");
1746               quote_argument (emacs_socket, argv[i]);
1747               send_to_emacs (emacs_socket, " ");
1748               continue;
1749             }
1750
1751           if (*argv[i] == '+')
1752             {
1753               char *p = argv[i] + 1;
1754               while (isdigit ((unsigned char) *p) || *p == ':') p++;
1755               if (*p == 0)
1756                 {
1757                   send_to_emacs (emacs_socket, "-position ");
1758                   quote_argument (emacs_socket, argv[i]);
1759                   send_to_emacs (emacs_socket, " ");
1760                   continue;
1761                 }
1762             }
1763 #ifdef WINDOWSNT
1764           else if (! file_name_absolute_p (argv[i])
1765                    && (isalpha (argv[i][0]) && argv[i][1] == ':'))
1766             /* Windows can have a different default directory for each
1767                drive, so the cwd passed via "-dir" is not sufficient
1768                to account for that.
1769                If the user uses <drive>:<relpath>, we hence need to be
1770                careful to expand <relpath> with the default directory
1771                corresponding to <drive>.  */
1772             {
1773               char *filename = (char *) xmalloc (MAX_PATH);
1774               DWORD size;
1775
1776               size = GetFullPathName (argv[i], MAX_PATH, filename, NULL);
1777               if (size > 0 && size < MAX_PATH)
1778                 argv[i] = filename;
1779               else
1780                 free (filename);
1781             }
1782 #endif
1783
1784           send_to_emacs (emacs_socket, "-file ");
1785           quote_argument (emacs_socket, argv[i]);
1786           send_to_emacs (emacs_socket, " ");
1787         }
1788     }
1789   else if (eval)
1790     {
1791       /* Read expressions interactively.  */
1792       while ((str = fgets (string, BUFSIZ, stdin)))
1793         {
1794           send_to_emacs (emacs_socket, "-eval ");
1795           quote_argument (emacs_socket, str);
1796         }
1797       send_to_emacs (emacs_socket, " ");
1798     }
1799
1800   send_to_emacs (emacs_socket, "\n");
1801
1802   /* Wait for an answer. */
1803   if (!eval && !tty && !nowait && !quiet)
1804     {
1805       printf ("Waiting for Emacs...");
1806       needlf = 2;
1807     }
1808   fflush (stdout);
1809   while (fdatasync (1) != 0 && errno == EINTR)
1810     continue;
1811
1812   /* Now, wait for an answer and print any messages.  */
1813   while (exit_status == EXIT_SUCCESS)
1814     {
1815       char *p, *end_p;
1816       do
1817         {
1818           errno = 0;
1819           rl = recv (emacs_socket, string, BUFSIZ, 0);
1820         }
1821       /* If we receive a signal (e.g. SIGWINCH, which we pass
1822          through to Emacs), on some OSes we get EINTR and must retry. */
1823       while (rl < 0 && errno == EINTR);
1824
1825       if (rl <= 0)
1826         break;
1827
1828       string[rl] = '\0';
1829
1830       /* Loop over all NL-terminated messages.  */
1831       for (end_p = p = string; end_p != NULL && *end_p != '\0'; p = end_p)
1832         {
1833           end_p = strchr (p, '\n');
1834           if (end_p != NULL)
1835             *end_p++ = '\0';
1836
1837           if (strprefix ("-emacs-pid ", p))
1838             {
1839               /* -emacs-pid PID: The process id of the Emacs process. */
1840               emacs_pid = strtol (p + strlen ("-emacs-pid"), NULL, 10);
1841             }
1842           else if (strprefix ("-window-system-unsupported ", p))
1843             {
1844               /* -window-system-unsupported: Emacs was compiled without support
1845                  for whatever window system we tried.  Try the alternate
1846                  display, or, failing that, try the terminal.  */
1847               if (alt_display)
1848                 {
1849                   display = alt_display;
1850                   alt_display = NULL;
1851                 }
1852               else
1853                 {
1854                   nowait = 0;
1855                   tty = 1;
1856                 }
1857
1858               goto retry;
1859             }
1860           else if (strprefix ("-print ", p))
1861             {
1862               /* -print STRING: Print STRING on the terminal. */
1863               str = unquote_argument (p + strlen ("-print "));
1864               if (needlf)
1865                 printf ("\n");
1866               printf ("%s", str);
1867               needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
1868             }
1869           else if (strprefix ("-print-nonl ", p))
1870             {
1871               /* -print-nonl STRING: Print STRING on the terminal.
1872                  Used to continue a preceding -print command.  */
1873               str = unquote_argument (p + strlen ("-print-nonl "));
1874               printf ("%s", str);
1875               needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
1876             }
1877           else if (strprefix ("-error ", p))
1878             {
1879               /* -error DESCRIPTION: Signal an error on the terminal. */
1880               str = unquote_argument (p + strlen ("-error "));
1881               if (needlf)
1882                 printf ("\n");
1883               fprintf (stderr, "*ERROR*: %s", str);
1884               needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
1885               exit_status = EXIT_FAILURE;
1886             }
1887 #ifdef SIGSTOP
1888           else if (strprefix ("-suspend ", p))
1889             {
1890               /* -suspend: Suspend this terminal, i.e., stop the process. */
1891               if (needlf)
1892                 printf ("\n");
1893               needlf = 0;
1894               kill (0, SIGSTOP);
1895             }
1896 #endif
1897           else
1898             {
1899               /* Unknown command. */
1900               if (needlf)
1901                 printf ("\n");
1902               needlf = 0;
1903               printf ("*ERROR*: Unknown message: %s\n", p);
1904             }
1905         }
1906     }
1907
1908   if (needlf)
1909     printf ("\n");
1910   fflush (stdout);
1911   while (fdatasync (1) != 0 && errno == EINTR)
1912     continue;
1913
1914   if (rl < 0)
1915     exit_status = EXIT_FAILURE;
1916
1917   CLOSE_SOCKET (emacs_socket);
1918   return exit_status;
1919 }
1920
1921 #endif /* HAVE_SOCKETS && HAVE_INET_SOCKETS */