lib-src/emacsclient.c

   1 /* Client process that communicates with GNU Emacs acting as server.
   2    Copyright (C) 1986, 1987, 1994, 1999, 2000, 2001, 2003
   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
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #undef signal
  30
  31 #include <ctype.h>
  32 #include <stdio.h>
  33 #include <getopt.h>
  34 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37
  38 #ifdef VMS
  39 # include "vms-pwd.h"
  40 #else
  41 # include <pwd.h>
  42 #endif /* not VMS */
  43
  44
  45 /****************************************/
  46
  47 #include <errno.h>
  48 #include <signal.h>
  49
  50 #ifndef INCLUDED_FCNTL
  51 #define INCLUDED_FCNTL
  52 #include <fcntl.h>
  53 #endif
  54
  55 #ifdef HAVE_TERMIOS
  56 #ifndef NO_TERMIO
  57 #include <termio.h>
  58 #endif
  59 #include <termios.h>
  60 #endif /* not HAVE_TERMIOS */
  61
  62 #ifdef __GNU_LIBRARY__
  63 #include <sys/ioctl.h>
  64 #include <termios.h>
  65 #endif
  66
  67 #if (defined (POSIX) || defined (NEED_UNISTD_H)) && defined (HAVE_UNISTD_H)
  68 #include <unistd.h>
  69 #endif
  70
  71
  72 \f
  73 /* Try to establish the correct character to disable terminal functions
  74    in a system-independent manner.  Note that USG (at least) define
  75    _POSIX_VDISABLE as 0!  */
  76
  77 #ifdef _POSIX_VDISABLE
  78 #define CDISABLE _POSIX_VDISABLE
  79 #else /* not _POSIX_VDISABLE */
  80 #ifdef CDEL
  81 #undef CDISABLE
  82 #define CDISABLE CDEL
  83 #else /* not CDEL */
  84 #define CDISABLE 255
  85 #endif /* not CDEL */
  86 #endif /* not _POSIX_VDISABLE */
  87 \f
  88
  89
  90 /****************************************/
  91
  92 char *getenv (), *getwd ();
  93 char *getcwd ();
  94
  95 /* This is defined with -D from the compilation command,
  96    which extracts it from ../lisp/version.el.  */
  97
  98 #ifndef VERSION
  99 #define VERSION "unspecified"
 100 #endif
 101 \f
 102 /* Name used to invoke this program.  */
 103 char *progname;
 104
 105 /* The first argument to main. */
 106 int main_argc;
 107
 108 /* The second argument to main. */
 109 char **main_argv;
 110
 111 /* Nonzero means don't wait for a response from Emacs.  --no-wait.  */
 112 int nowait = 0;
 113
 114 /* Nonzero means args are expressions to be evaluated.  --eval.  */
 115 int eval = 0;
 116
 117 /* The display on which Emacs should work.  --display.  */
 118 char *display = NULL;
 119
 120 /* Nonzero means open a new Emacs frame on the current terminal. */
 121 int here = 0;
 122
 123 /* If non-NULL, the name of an editor to fallback to if the server
 124    is not running.  --alternate-editor.   */
 125 const char * alternate_editor = NULL;
 126
 127 /* If non-NULL, the filename of the UNIX socket.  */
 128 char *socket_name = NULL;
 129
 130 void print_help_and_exit ();
 131
 132 struct option longopts[] =
 133 {
 134   { "no-wait",  no_argument,       NULL, 'n' },
 135   { "eval",     no_argument,       NULL, 'e' },
 136   { "help",     no_argument,       NULL, 'H' },
 137   { "version",  no_argument,       NULL, 'V' },
 138   { "here",     no_argument,       NULL, 'h' },
 139   { "alternate-editor", required_argument, NULL, 'a' },
 140   { "socket-name",      required_argument, NULL, 's' },
 141   { "display",  required_argument, NULL, 'd' },
 142   { 0, 0, 0, 0 }
 143 };
 144
 145 /* Decode the options from argv and argc.
 146    The global variable `optind' will say how many arguments we used up.  */
 147
 148 void
 149 decode_options (argc, argv)
 150      int argc;
 151      char **argv;
 152 {
 153   while (1)
 154     {
 155       int opt = getopt_long (argc, argv,
 156                              "VHnea:s:d:h", longopts, 0);
 157
 158       if (opt == EOF)
 159         break;
 160
 161       alternate_editor = getenv ("ALTERNATE_EDITOR");
 162
 163       switch (opt)
 164         {
 165         case 0:
 166           /* If getopt returns 0, then it has already processed a
 167              long-named option.  We should do nothing.  */
 168           break;
 169
 170         case 'a':
 171           alternate_editor = optarg;
 172           break;
 173
 174         case 's':
 175           socket_name = optarg;
 176           break;
 177
 178         case 'd':
 179           display = optarg;
 180           break;
 181
 182         case 'n':
 183           nowait = 1;
 184           break;
 185
 186         case 'e':
 187           eval = 1;
 188           break;
 189
 190         case 'V':
 191           printf ("emacsclient %s\n", VERSION);
 192           exit (0);
 193           break;
 194
 195         case 'h':
 196           here = 1;
 197           break;
 198
 199         case 'H':
 200           print_help_and_exit ();
 201           break;
 202
 203         default:
 204           fprintf (stderr, "Try `%s --help' for more information\n", progname);
 205           exit (1);
 206           break;
 207         }
 208     }
 209
 210   if (here) {
 211     nowait = 0;
 212     display = 0;
 213   }
 214
 215 }
 216
 217 void
 218 print_help_and_exit ()
 219 {
 220   printf (
 221           "Usage: %s [OPTIONS] FILE...\n\
 222 Tell the Emacs server to visit the specified files.\n\
 223 Every FILE can be either just a FILENAME or [+LINE[:COLUMN]] FILENAME.\n\
 224 \n\
 225 The following OPTIONS are accepted:\n\
 226 -V, --version           Just print a version info and return\n\
 227 -H, --help              Print this usage information message\n\
 228 -h, --here              Open a new Emacs frame on the current terminal\n\
 229 -n, --no-wait           Don't wait for the server to return\n\
 230 -e, --eval              Evaluate the FILE arguments as ELisp expressions\n\
 231 -d, --display=DISPLAY   Visit the file in the given display\n\
 232 -s, --socket-name=FILENAME\n\
 233                         Set the filename of the UNIX socket for communication\n\
 234 -a, --alternate-editor=EDITOR\n\
 235                         Editor to fallback to if the server is not running\n\
 236 \n\
 237 Report bugs to bug-gnu-emacs@gnu.org.\n", progname);
 238   exit (0);
 239 }
 240
 241 /* In NAME, insert a & before each &, each space, each newline, and
 242    any initial -.  Change spaces to underscores, too, so that the
 243    return value never contains a space.  */
 244
 245 void
 246 quote_file_name (name, stream)
 247      char *name;
 248      FILE *stream;
 249 {
 250   char *copy = (char *) malloc (strlen (name) * 2 + 1);
 251   char *p, *q;
 252
 253   p = name;
 254   q = copy;
 255   while (*p)
 256     {
 257       if (*p == ' ')
 258         {
 259           *q++ = '&';
 260           *q++ = '_';
 261           p++;
 262         }
 263       else if (*p == '\n')
 264         {
 265           *q++ = '&';
 266           *q++ = 'n';
 267           p++;
 268         }
 269       else
 270         {
 271           if (*p == '&' || (*p == '-' && p == name))
 272             *q++ = '&';
 273           *q++ = *p++;
 274         }
 275     }
 276   *q++ = 0;
 277
 278   fprintf (stream, copy);
 279
 280   free (copy);
 281 }
 282
 283 /* Like malloc but get fatal error if memory is exhausted.  */
 284
 285 long *
 286 xmalloc (size)
 287      unsigned int size;
 288 {
 289   long *result = (long *) malloc (size);
 290   if (result == NULL)
 291   {
 292     perror ("malloc");
 293     exit (1);
 294   }
 295   return result;
 296 }
 297 \f
 298 /*
 299   Try to run a different command, or --if no alternate editor is
 300   defined-- exit with an errorcode.
 301 */
 302 void
 303 fail ()
 304 {
 305   if (alternate_editor)
 306     {
 307       int i = optind - 1;
 308       execvp (alternate_editor, main_argv + i);
 309       return;
 310     }
 311   else
 312     {
 313       exit (1);
 314     }
 315 }
 316
 317 \f
 318 #ifdef HAVE_TERMIOS
 319
 320 /* Adapted from emacs_get_tty() in sysdep.c. */
 321 int
 322 ec_get_tty (int fd, struct termios *settings)
 323 {
 324   bzero (settings, sizeof (struct termios));
 325   if (tcgetattr (fd, settings) < 0)
 326     return -1;
 327   return 0;
 328 }
 329
 330 /* Adapted from emacs_set_tty() in sysdep.c. */
 331 int
 332 ec_set_tty (int fd, struct termios *settings, int flushp)
 333 {
 334   /* Set the primary parameters - baud rate, character size, etcetera.  */
 335
 336   int i;
 337   /* We have those nifty POSIX tcmumbleattr functions.
 338      William J. Smith <wjs@wiis.wang.com> writes:
 339      "POSIX 1003.1 defines tcsetattr to return success if it was
 340      able to perform any of the requested actions, even if some
 341      of the requested actions could not be performed.
 342      We must read settings back to ensure tty setup properly.
 343      AIX requires this to keep tty from hanging occasionally."  */
 344   /* This make sure that we don't loop indefinitely in here.  */
 345   for (i = 0 ; i < 10 ; i++)
 346     if (tcsetattr (fd, flushp ? TCSAFLUSH : TCSADRAIN, settings) < 0)
 347       {
 348         if (errno == EINTR)
 349           continue;
 350         else
 351           return -1;
 352       }
 353     else
 354       {
 355         struct termios new;
 356
 357         bzero (&new, sizeof (new));
 358         /* Get the current settings, and see if they're what we asked for.  */
 359         tcgetattr (fd, &new);
 360         /* We cannot use memcmp on the whole structure here because under
 361          * aix386 the termios structure has some reserved field that may
 362          * not be filled in.
 363          */
 364         if (   new.c_iflag == settings->c_iflag
 365             && new.c_oflag == settings->c_oflag
 366             && new.c_cflag == settings->c_cflag
 367             && new.c_lflag == settings->c_lflag
 368             && memcmp (new.c_cc, settings->c_cc, NCCS) == 0)
 369           break;
 370         else
 371           continue;
 372       }
 373   return 0;
 374 }
 375
 376 int master;
 377 char *pty_name;
 378
 379 struct termios old_tty;
 380 struct termios tty;
 381 int old_tty_valid;
 382
 383 int tty_erase_char;
 384 int flow_control = 0;
 385 int meta_key = 0;
 386 char _sobuf[BUFSIZ];
 387 int emacs_pid;
 388
 389 /* Adapted from init_sys_modes() in sysdep.c. */
 390 int
 391 init_tty ()
 392 {
 393   if (! isatty (0))
 394     {
 395       fprintf (stderr, "%s: Input is not a terminal", "init_tty");
 396       return 0;
 397     }
 398
 399   ec_get_tty (0, &old_tty);
 400   old_tty_valid = 1;
 401   tty = old_tty;
 402
 403   tty_erase_char = old_tty.c_cc[VERASE];
 404
 405   tty.c_iflag |= (IGNBRK);      /* Ignore break condition */
 406   tty.c_iflag &= ~ICRNL;        /* Disable map of CR to NL on input */
 407 #ifdef INLCR
 408   tty.c_iflag &= ~INLCR;        /* Disable map of NL to CR on input */
 409 #endif
 410 #ifdef ISTRIP
 411   tty.c_iflag &= ~ISTRIP;       /* don't strip 8th bit on input */
 412 #endif
 413   tty.c_lflag &= ~ECHO;         /* Disable echo */
 414   tty.c_lflag &= ~ICANON;       /* Disable erase/kill processing */
 415 #ifdef IEXTEN
 416   tty.c_lflag &= ~IEXTEN;       /* Disable other editing characters.  */
 417 #endif
 418   tty.c_lflag |= ISIG;          /* Enable signals */
 419   if (flow_control)
 420     {
 421       tty.c_iflag |= IXON;      /* Enable start/stop output control */
 422 #ifdef IXANY
 423       tty.c_iflag &= ~IXANY;
 424 #endif /* IXANY */
 425     }
 426   else
 427     tty.c_iflag &= ~IXON;       /* Disable start/stop output control */
 428   tty.c_oflag &= ~ONLCR;        /* Disable map of NL to CR-NL
 429                                    on output */
 430   tty.c_oflag &= ~TAB3;         /* Disable tab expansion */
 431 #ifdef CS8
 432   if (meta_key)
 433     {
 434       tty.c_cflag |= CS8;       /* allow 8th bit on input */
 435       tty.c_cflag &= ~PARENB;   /* Don't check parity */
 436     }
 437 #endif
 438   tty.c_cc[VINTR] = CDISABLE;
 439   tty.c_cc[VQUIT] = CDISABLE;
 440   tty.c_cc[VMIN] = 1;      /* Input should wait for at least 1 char */
 441   tty.c_cc[VTIME] = 0;          /* no matter how long that takes.  */
 442 #ifdef VSWTCH
 443   tty.c_cc[VSWTCH] = CDISABLE;  /* Turn off shell layering use of C-z */
 444 #endif
 445
 446 #ifdef VSUSP
 447   tty.c_cc[VSUSP] = CDISABLE;   /* Turn off mips handling of C-z.  */
 448 #endif /* VSUSP */
 449 #ifdef V_DSUSP
 450   tty.c_cc[V_DSUSP] = CDISABLE; /* Turn off mips handling of C-y.  */
 451 #endif /* V_DSUSP */
 452 #ifdef VDSUSP /* Some systems have VDSUSP, some have V_DSUSP.  */
 453   tty.c_cc[VDSUSP] = CDISABLE;
 454 #endif /* VDSUSP */
 455 #ifdef VLNEXT
 456   tty.c_cc[VLNEXT] = CDISABLE;
 457 #endif /* VLNEXT */
 458 #ifdef VREPRINT
 459   tty.c_cc[VREPRINT] = CDISABLE;
 460 #endif /* VREPRINT */
 461 #ifdef VWERASE
 462   tty.c_cc[VWERASE] = CDISABLE;
 463 #endif /* VWERASE */
 464 #ifdef VDISCARD
 465   tty.c_cc[VDISCARD] = CDISABLE;
 466 #endif /* VDISCARD */
 467
 468   if (flow_control)
 469     {
 470 #ifdef VSTART
 471       tty.c_cc[VSTART] = '\021';
 472 #endif /* VSTART */
 473 #ifdef VSTOP
 474       tty.c_cc[VSTOP] = '\023';
 475 #endif /* VSTOP */
 476     }
 477   else
 478     {
 479 #ifdef VSTART
 480       tty.c_cc[VSTART] = CDISABLE;
 481 #endif /* VSTART */
 482 #ifdef VSTOP
 483       tty.c_cc[VSTOP] = CDISABLE;
 484 #endif /* VSTOP */
 485     }
 486
 487 #ifdef SET_LINE_DISCIPLINE
 488   /* Need to explicitly request TERMIODISC line discipline or
 489      Ultrix's termios does not work correctly.  */
 490   tty.c_line = SET_LINE_DISCIPLINE;
 491 #endif
 492
 493 #ifdef AIX
 494 #ifndef IBMR2AIX
 495   /* AIX enhanced edit loses NULs, so disable it.  */
 496   tty.c_line = 0;
 497   tty.c_iflag &= ~ASCEDIT;
 498 #else
 499   tty.c_cc[VSTRT] = 255;
 500   tty.c_cc[VSTOP] = 255;
 501   tty.c_cc[VSUSP] = 255;
 502   tty.c_cc[VDSUSP] = 255;
 503 #endif /* IBMR2AIX */
 504   if (flow_control)
 505     {
 506 #ifdef VSTART
 507       tty.c_cc[VSTART] = '\021';
 508 #endif /* VSTART */
 509 #ifdef VSTOP
 510       tty.c_cc[VSTOP] = '\023';
 511 #endif /* VSTOP */
 512     }
 513   /* Also, PTY overloads NUL and BREAK.
 514      don't ignore break, but don't signal either, so it looks like NUL.
 515      This really serves a purpose only if running in an XTERM window
 516      or via TELNET or the like, but does no harm elsewhere.  */
 517   tty.c_iflag &= ~IGNBRK;
 518   tty.c_iflag &= ~BRKINT;
 519 #endif /* AIX */
 520
 521   ec_set_tty (0, &tty, 0);
 522
 523       /* This code added to insure that, if flow-control is not to be used,
 524          we have an unlocked terminal at the start. */
 525
 526 #ifdef TCXONC
 527   if (!flow_control) ioctl (0, TCXONC, 1);
 528 #endif
 529 #ifndef APOLLO
 530 #ifdef TIOCSTART
 531   if (!flow_control) ioctl (0, TIOCSTART, 0);
 532 #endif
 533 #endif
 534
 535 #if defined (HAVE_TERMIOS) || defined (HPUX9)
 536 #ifdef TCOON
 537   if (!flow_control) tcflow (0, TCOON);
 538 #endif
 539 #endif
 540
 541 #ifdef _IOFBF
 542   /* This symbol is defined on recent USG systems.
 543      Someone says without this call USG won't really buffer the file
 544      even with a call to setbuf. */
 545   setvbuf (stdout, (char *) _sobuf, _IOFBF, sizeof _sobuf);
 546 #else
 547   setbuf (stdout, (char *) _sobuf);
 548 #endif
 549
 550   return 1;
 551 }
 552
 553 void
 554 window_change ()
 555 {
 556   int width = 0, height = 0;
 557
 558 #ifdef TIOCGWINSZ
 559   {
 560     /* BSD-style.  */
 561     struct winsize size;
 562
 563     if (ioctl (0, TIOCGWINSZ, &size) == -1)
 564       width = height = 0;
 565     else
 566       {
 567         width = size.ws_col;
 568         height = size.ws_row;
 569       }
 570   }
 571 #else
 572 #ifdef TIOCGSIZE
 573   {
 574     /* SunOS - style.  */
 575     struct ttysize size;
 576
 577     if (ioctl (0, TIOCGSIZE, &size) == -1)
 578       width = height = 0;
 579     else
 580       {
 581         width = size.ts_cols;
 582         height = size.ts_lines;
 583       }
 584   }
 585 #endif /* not SunOS-style */
 586 #endif /* not BSD-style */
 587
 588 #ifdef TIOCSWINSZ
 589   {
 590     /* BSD-style.  */
 591     struct winsize size;
 592     size.ws_row = height;
 593     size.ws_col = width;
 594
 595     ioctl (master, TIOCSWINSZ, &size);
 596   }
 597 #else
 598 #ifdef TIOCSSIZE
 599   {
 600     /* SunOS - style.  */
 601     struct ttysize size;
 602     size.ts_lines = height;
 603     size.ts_cols = width;
 604
 605     ioctl (master, TIOCGSIZE, &size);
 606   }
 607 #endif /* not SunOS-style */
 608 #endif /* not BSD-style */
 609
 610   if (emacs_pid && width && height)
 611     kill (emacs_pid, SIGWINCH);
 612 }
 613
 614 int in_conversation = 0;
 615 int quit_conversation = 0;
 616
 617 SIGTYPE
 618 hang_up_signal (int signalnum)
 619 {
 620   int old_errno = errno;
 621
 622   if (! in_conversation)
 623     return;
 624
 625   quit_conversation = 1;
 626
 627   errno = old_errno;
 628 }
 629
 630 SIGTYPE
 631 window_change_signal (int signalnum)
 632 {
 633   int old_errno = errno;
 634
 635   if (! in_conversation)
 636     goto end;
 637
 638   window_change();
 639
 640  end:
 641   signal (SIGWINCH, window_change_signal);
 642   errno = old_errno;
 643 }
 644
 645 int
 646 init_signals ()
 647 {
 648   /* Set up signal handlers. */
 649   signal (SIGWINCH, window_change_signal);
 650   signal (SIGHUP, hang_up_signal);
 651
 652   return 1;
 653 }
 654
 655
 656
 657 /* Adapted from reset_sys_modes in sysdep.c. */
 658 int
 659 reset_tty ()
 660 {
 661   fflush (stdout);
 662 #ifdef BSD_SYSTEM
 663 #ifndef BSD4_1
 664   /* Avoid possible loss of output when changing terminal modes.  */
 665   fsync (fileno (stdout));
 666 #endif
 667 #endif
 668
 669 #ifdef F_SETFL
 670 #ifdef O_NDELAY
 671   fcntl (0, F_SETFL, fcntl (0, F_GETFL, 0) & ~O_NDELAY);
 672 #endif
 673 #endif /* F_SETFL */
 674
 675   if (old_tty_valid)
 676     while (ec_set_tty (0, &old_tty, 0) < 0 && errno == EINTR)
 677       ;
 678
 679   return 1;
 680 }
 681
 682
 683 int
 684 init_pty ()
 685 {
 686   master = getpt ();
 687   if (master < 0)
 688     return 0;
 689
 690   if (grantpt (master) < 0 || unlockpt (master) < 0)
 691     goto close_master;
 692   pty_name = strdup (ptsname (master));
 693   if (! pty_name)
 694     goto close_master;
 695
 696   /* Propagate window size. */
 697   window_change ();
 698
 699   return 1;
 700
 701  close_master:
 702   close (master);
 703   return 0;
 704 }
 705
 706 int
 707 copy_from_to (int in, int out, int sigio)
 708 {
 709   static char buf[BUFSIZ];
 710   int nread = read (in, &buf, BUFSIZ);
 711   if (nread == 0)
 712     return 1;                   /* EOF */
 713   else if (nread < 0 && errno != EAGAIN)
 714     return 0;                   /* Error */
 715   else if (nread > 0)
 716     {
 717       int r = 0;
 718       int written = 0;
 719
 720       do {
 721         r = write (out, &buf, nread);
 722       } while ((r < 0 && errno == EAGAIN)
 723                || (r > 0 && (written += r) && written != nread));
 724
 725       if (r < 0)
 726         return 0;               /* Error */
 727
 728       if (emacs_pid && sigio)
 729         {
 730           kill (emacs_pid, SIGIO);
 731         }
 732     }
 733   return 1;
 734 }
 735
 736 int
 737 pty_conversation (FILE *in)
 738 {
 739   char *str;
 740   char string[BUFSIZ];
 741   fd_set set;
 742
 743   in_conversation = 1;
 744
 745   while (! quit_conversation) {
 746     int res;
 747
 748     FD_ZERO (&set);
 749     FD_SET (master, &set);
 750     FD_SET (1, &set);
 751     FD_SET (fileno (in), &set);
 752     res = select (FD_SETSIZE, &set, NULL, NULL, NULL);
 753     if (res < 0)
 754       {
 755         if (errno != EINTR)
 756           return 0;
 757       }
 758     else if (res > 0)
 759       {
 760         if (FD_ISSET (master, &set))
 761           {
 762             /* Copy Emacs output to stdout. */
 763             if (! copy_from_to (master, 0, 0))
 764               return 1;
 765           }
 766         if (FD_ISSET (1, &set))
 767           {
 768             /* Forward user input to Emacs. */
 769             if (! copy_from_to (1, master, 1))
 770               return 1;
 771           }
 772         if (FD_ISSET (fileno (in), &set))
 773           {
 774             if (! emacs_pid)
 775               {
 776                 /* Get the pid of the Emacs process.
 777                    XXX Is there is some nifty libc/kernel feature for doing this?
 778                 */
 779                 str = fgets (string, BUFSIZ, in);
 780                 if (! str)
 781                   {
 782                     reset_tty ();
 783                     fprintf (stderr, "%s: %s\n", progname, str);
 784                     fail ();
 785                   }
 786
 787                 emacs_pid = atoi (str);
 788               }
 789           }
 790       }
 791   }
 792   return 1;
 793 }
 794
 795 #endif /* HAVE_TERMIOS */
 796
 797 \f
 798 #if !defined (HAVE_SOCKETS) || defined (NO_SOCKETS_IN_FILE_SYSTEM)
 799
 800 int
 801 main (argc, argv)
 802      int argc;
 803      char **argv;
 804 {
 805   fprintf (stderr, "%s: Sorry, the Emacs server is supported only\n",
 806            argv[0]);
 807   fprintf (stderr, "on systems with Berkeley sockets.\n");
 808
 809   fail (argc, argv);
 810 }
 811
 812 #else /* HAVE_SOCKETS */
 813
 814 #include <sys/types.h>
 815 #include <sys/socket.h>
 816 #include <sys/un.h>
 817 #include <sys/stat.h>
 818 #include <errno.h>
 819
 820 extern char *strerror ();
 821 extern int errno;
 822
 823 /* Three possibilities:
 824    2 - can't be `stat'ed                (sets errno)
 825    1 - isn't owned by us
 826    0 - success: none of the above */
 827
 828 static int
 829 socket_status (socket_name)
 830      char *socket_name;
 831 {
 832   struct stat statbfr;
 833
 834   if (stat (socket_name, &statbfr) == -1)
 835     return 2;
 836
 837   if (statbfr.st_uid != geteuid ())
 838     return 1;
 839
 840   return 0;
 841 }
 842
 843 int
 844 main (argc, argv)
 845      int argc;
 846      char **argv;
 847 {
 848   char *system_name;
 849   int system_name_length;
 850   int s, i, needlf = 0;
 851   FILE *out, *in;
 852   struct sockaddr_un server;
 853   char *cwd, *str;
 854   char string[BUFSIZ];
 855
 856   main_argc = argc;
 857   main_argv = argv;
 858   progname = argv[0];
 859
 860   /* Process options.  */
 861   decode_options (argc, argv);
 862
 863   if ((argc - optind < 1) && !eval && !here)
 864     {
 865       fprintf (stderr, "%s: file name or argument required\n", progname);
 866       fprintf (stderr, "Try `%s --help' for more information\n", progname);
 867       exit (1);
 868     }
 869
 870   /*
 871    * Open up an AF_UNIX socket in this person's home directory
 872    */
 873
 874   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
 875     {
 876       fprintf (stderr, "%s: ", argv[0]);
 877       perror ("socket");
 878       fail (argc, argv);
 879     }
 880
 881   server.sun_family = AF_UNIX;
 882
 883   {
 884     char *dot;
 885     system_name_length = 32;
 886
 887     while (1)
 888       {
 889         system_name = (char *) xmalloc (system_name_length + 1);
 890
 891         /* system_name must be null-terminated string.  */
 892         system_name[system_name_length] = '\0';
 893
 894         if (gethostname (system_name, system_name_length) == 0)
 895           break;
 896
 897         free (system_name);
 898         system_name_length *= 2;
 899       }
 900
 901     /* We always use the non-dotted host name, for simplicity.  */
 902     dot = index (system_name, '.');
 903     if (dot)
 904       *dot = '\0';
 905   }
 906
 907   {
 908     int sock_status = 0;
 909
 910     if (! socket_name)
 911       {
 912         socket_name = alloca (system_name_length + 100);
 913         sprintf (socket_name, "/tmp/emacs%d-%s/server",
 914                  (int) geteuid (), system_name);
 915       }
 916
 917     if (strlen (socket_name) < sizeof (server.sun_path))
 918       strcpy (server.sun_path, socket_name);
 919     else
 920       fprintf (stderr, "%s: socket-name %s too long",
 921                argv[0], socket_name);
 922
 923     /* See if the socket exists, and if it's owned by us. */
 924     sock_status = socket_status (server.sun_path);
 925     if (sock_status)
 926       {
 927         /* Failing that, see if LOGNAME or USER exist and differ from
 928            our euid.  If so, look for a socket based on the UID
 929            associated with the name.  This is reminiscent of the logic
 930            that init_editfns uses to set the global Vuser_full_name.  */
 931
 932         char *user_name = (char *) getenv ("LOGNAME");
 933         if (!user_name)
 934           user_name = (char *) getenv ("USER");
 935
 936         if (user_name)
 937           {
 938             struct passwd *pw = getpwnam (user_name);
 939             if (pw && (pw->pw_uid != geteuid ()))
 940               {
 941                 /* We're running under su, apparently. */
 942                 sprintf (server.sun_path, "/tmp/esrv%d-%s",
 943                          (int) pw->pw_uid, system_name);
 944                 sock_status = socket_status (server.sun_path);
 945               }
 946           }
 947       }
 948
 949      switch (sock_status)
 950        {
 951        case 1:
 952          /* There's a socket, but it isn't owned by us.  This is OK if
 953             we are root. */
 954          if (0 != geteuid ())
 955            {
 956              fprintf (stderr, "%s: Invalid socket owner\n", argv[0]);
 957              fail (argc, argv);
 958            }
 959          break;
 960
 961        case 2:
 962          /* `stat' failed */
 963          if (errno == ENOENT)
 964            fprintf (stderr,
 965                     "%s: can't find socket; have you started the server?\n\
 966 To start the server in Emacs, type \"M-x server-start\".\n",
 967                     argv[0]);
 968          else
 969            fprintf (stderr, "%s: can't stat %s: %s\n",
 970                     argv[0], server.sun_path, strerror (errno));
 971          fail (argc, argv);
 972          break;
 973        }
 974   }
 975
 976   if (connect (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2)
 977       < 0)
 978     {
 979       fprintf (stderr, "%s: ", argv[0]);
 980       perror ("connect");
 981       fail (argc, argv);
 982     }
 983
 984   /* We use the stream OUT to send our command to the server.  */
 985   if ((out = fdopen (s, "r+")) == NULL)
 986     {
 987       fprintf (stderr, "%s: ", argv[0]);
 988       perror ("fdopen");
 989       fail (argc, argv);
 990     }
 991
 992   /* We use the stream IN to read the response.
 993      We used to use just one stream for both output and input
 994      on the socket, but reversing direction works nonportably:
 995      on some systems, the output appears as the first input;
 996      on other systems it does not.  */
 997   if ((in = fdopen (s, "r+")) == NULL)
 998     {
 999       fprintf (stderr, "%s: ", argv[0]);
1000       perror ("fdopen");
1001       fail (argc, argv);
1002     }
1003
1004 #ifdef HAVE_GETCWD
1005   cwd = getcwd (string, sizeof string);
1006 #else
1007   cwd = getwd (string);
1008 #endif
1009   if (cwd == 0)
1010     {
1011       /* getwd puts message in STRING if it fails.  */
1012
1013 #ifdef HAVE_GETCWD
1014       fprintf (stderr, "%s: %s (%s)\n", argv[0],
1015                "Cannot get current working directory", strerror (errno));
1016 #else
1017       fprintf (stderr, "%s: %s (%s)\n", argv[0], string, strerror (errno));
1018 #endif
1019       fail (argc, argv);
1020     }
1021
1022   if (nowait)
1023     fprintf (out, "-nowait ");
1024
1025   if (eval)
1026     fprintf (out, "-eval ");
1027
1028   if (display)
1029     {
1030       fprintf (out, "-display ");
1031       quote_file_name (display, out);
1032       fprintf (out, " ");
1033     }
1034
1035   if (here)
1036     {
1037       if (! init_signals ())
1038         {
1039           fprintf (stderr, "%s: ", argv[0]);
1040           perror ("fdopen");
1041           fail (argc, argv);
1042         }
1043
1044       if (! init_tty ())
1045         {
1046           reset_tty ();
1047           fprintf (stderr, "%s: ", argv[0]);
1048           perror ("fdopen");
1049           fail (argc, argv);
1050         }
1051
1052       if (! init_pty ())
1053         {
1054           reset_tty ();
1055           fprintf (stderr, "%s: ", argv[0]);
1056           perror ("fdopen");
1057           fail (argc, argv);
1058         }
1059
1060       fprintf (out, "-pty ");
1061       quote_file_name (pty_name, out);
1062       fprintf (out, " ");
1063       quote_file_name (getenv("TERM"), out);
1064       fprintf (out, " ");
1065     }
1066
1067   if ((argc - optind > 0))
1068     {
1069       for (i = optind; i < argc; i++)
1070         {
1071           if (eval)
1072             ; /* Don't prepend any cwd or anything like that.  */
1073           else if (*argv[i] == '+')
1074             {
1075               char *p = argv[i] + 1;
1076               while (isdigit ((unsigned char) *p) || *p == ':') p++;
1077               if (*p != 0)
1078                 {
1079                   quote_file_name (cwd, out);
1080                   fprintf (out, "/");
1081                 }
1082             }
1083           else if (*argv[i] != '/')
1084             {
1085               quote_file_name (cwd, out);
1086               fprintf (out, "/");
1087             }
1088
1089           quote_file_name (argv[i], out);
1090           fprintf (out, " ");
1091         }
1092     }
1093   else
1094     {
1095       if (!here)
1096         {
1097           while ((str = fgets (string, BUFSIZ, stdin)))
1098             {
1099               quote_file_name (str, out);
1100             }
1101           fprintf (out, " ");
1102         }
1103     }
1104
1105   fprintf (out, "\n");
1106   fflush (out);
1107
1108   /* Maybe wait for an answer.   */
1109   if (nowait)
1110     {
1111       reset_tty ();
1112       return 0;
1113     }
1114
1115   if (here)
1116     {
1117       if (! pty_conversation (out))
1118         {
1119           reset_tty ();
1120           fprintf (stderr, "%s: ", argv[0]);
1121           perror ("fdopen");
1122           fail (argc, argv);
1123         }
1124       close (master);
1125       reset_tty ();
1126       return 0;
1127     }
1128
1129   if (!eval)
1130     {
1131       printf ("Waiting for Emacs...");
1132       needlf = 2;
1133     }
1134   fflush (stdout);
1135
1136   /* Now, wait for an answer and print any messages.  */
1137   while ((str = fgets (string, BUFSIZ, in)))
1138     {
1139       if (needlf == 2)
1140         printf ("\n");
1141       printf ("%s", str);
1142       needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
1143     }
1144
1145   if (needlf)
1146     printf ("\n");
1147   fflush (stdout);
1148
1149   reset_tty ();
1150   return 0;
1151 }
1152
1153 #endif /* HAVE_SOCKETS */
1154 \f
1155 #ifndef HAVE_STRERROR
1156 char *
1157 strerror (errnum)
1158      int errnum;
1159 {
1160   extern char *sys_errlist[];
1161   extern int sys_nerr;
1162
1163   if (errnum >= 0 && errnum < sys_nerr)
1164     return sys_errlist[errnum];
1165   return (char *) "Unknown error";
1166 }
1167
1168 #endif /* ! HAVE_STRERROR */
1169
1170 /* arch-tag: f39bb9c4-73eb-477e-896d-50832e2ca9a7
1171    (do not change this comment) */