callproc.c 16.7 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Synchronous subprocess invocation for GNU Emacs.
2
   Copyright (C) 1985, 1986, 1987, 1988, 1992 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include <signal.h>
22
#include <errno.h>
Jim Blandy's avatar
Jim Blandy committed
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

#include "config.h"

/* Define SIGCHLD as an alias for SIGCLD.  */

#if !defined (SIGCHLD) && defined (SIGCLD)
#define SIGCHLD SIGCLD
#endif /* SIGCLD */

#include <sys/types.h>
#define PRIO_PROCESS 0
#include <sys/file.h>
#ifdef USG5
#include <fcntl.h>
#endif

#ifndef O_RDONLY
#define O_RDONLY 0
#endif

#ifndef O_WRONLY
#define O_WRONLY 1
#endif

#include "lisp.h"
#include "commands.h"
#include "buffer.h"
#include "paths.h"
#include "process.h"
52
#include "syssignal.h"
Jim Blandy's avatar
Jim Blandy committed
53 54 55 56 57 58 59 60 61

#ifdef VMS
extern noshare char **environ;
#else
extern char **environ;
#endif

#define max(a, b) ((a) > (b) ? (a) : (b))

62
Lisp_Object Vexec_path, Vexec_directory, Vdata_directory;
Jim Blandy's avatar
Jim Blandy committed
63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

Lisp_Object Vshell_file_name;

Lisp_Object Vprocess_environment;

/* True iff we are about to fork off a synchronous process or if we
   are waiting for it.  */
int synch_process_alive;

/* Nonzero => this is a string explaining death of synchronous subprocess.  */
char *synch_process_death;

/* If synch_process_death is zero,
   this is exit code of synchronous subprocess.  */
int synch_process_retcode;

#ifndef VMS  /* VMS version is in vmsproc.c.  */

81 82 83 84 85 86 87 88 89 90
static Lisp_Object
call_process_kill (fdpid)
     Lisp_Object fdpid;
{
  close (XFASTINT (Fcar (fdpid)));
  EMACS_KILLPG (XFASTINT (Fcdr (fdpid)), SIGKILL);
  synch_process_alive = 0;
  return Qnil;
}

Jim Blandy's avatar
Jim Blandy committed
91 92 93 94
Lisp_Object
call_process_cleanup (fdpid)
     Lisp_Object fdpid;
{
95 96 97 98 99 100 101 102 103 104 105 106 107 108
  register int pid = XFASTINT (Fcdr (fdpid));

  if (EMACS_KILLPG (pid, SIGINT) == 0)
    {
      int count = specpdl_ptr - specpdl;
      record_unwind_protect (call_process_kill, fdpid);
      message1 ("Waiting for process to die...(type C-g again to kill it instantly)");
      immediate_quit = 1;
      QUIT;
      wait_for_termination (pid);
      immediate_quit = 0;
      specpdl_ptr = specpdl + count; /* Discard the unwind protect.  */
      message1 ("Waiting for process to die...done");
    }
Jim Blandy's avatar
Jim Blandy committed
109
  synch_process_alive = 0;
110
  close (XFASTINT (Fcar (fdpid)));
Jim Blandy's avatar
Jim Blandy committed
111 112 113 114 115 116 117 118 119 120
  return Qnil;
}

DEFUN ("call-process", Fcall_process, Scall_process, 1, MANY, 0,
  "Call PROGRAM synchronously in separate process.\n\
The program's input comes from file INFILE (nil means `/dev/null').\n\
Insert output in BUFFER before point; t means current buffer;\n\
 nil for BUFFER means discard it; 0 means discard and don't wait.\n\
Fourth arg DISPLAY non-nil means redisplay buffer as output is inserted.\n\
Remaining arguments are strings passed as command arguments to PROGRAM.\n\
121
If BUFFER is 0, returns immediately with value nil.\n\
Jim Blandy's avatar
Jim Blandy committed
122
Otherwise waits for PROGRAM to terminate\n\
123
and returns a numeric exit status or a signal description string.\n\
124
If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.")
Jim Blandy's avatar
Jim Blandy committed
125 126 127 128
  (nargs, args)
     int nargs;
     register Lisp_Object *args;
{
129
  Lisp_Object display, infile, buffer, path, current_dir;
Jim Blandy's avatar
Jim Blandy committed
130 131 132 133 134 135 136 137 138 139 140 141 142
  int fd[2];
  int filefd;
  register int pid;
  char buf[1024];
  int count = specpdl_ptr - specpdl;
  register unsigned char **new_argv
    = (unsigned char **) alloca ((max (2, nargs - 2)) * sizeof (char *));
  struct buffer *old = current_buffer;
#if 0
  int mask;
#endif
  CHECK_STRING (args[0], 0);

143 144 145 146 147
  if (nargs >= 2 && ! NILP (args[1]))
    {
      infile = Fexpand_file_name (args[1], current_buffer->directory);
      CHECK_STRING (infile, 1);
    }
Jim Blandy's avatar
Jim Blandy committed
148
  else
149 150 151 152 153
#ifdef VMS
    infile = build_string ("NLA0:");
#else
    infile = build_string ("/dev/null");
#endif /* not VMS */
Jim Blandy's avatar
Jim Blandy committed
154

155 156 157
  if (nargs >= 3)
    {
      register Lisp_Object tem;
Richard M. Stallman's avatar
Richard M. Stallman committed
158

159 160 161 162 163 164 165 166 167 168 169
      buffer = tem = args[2];
      if (!(EQ (tem, Qnil)
	    || EQ (tem, Qt)
	    || XFASTINT (tem) == 0))
	{
	  buffer = Fget_buffer (tem);
	  CHECK_BUFFER (buffer, 2);
	}
    }
  else 
    buffer = Qnil;
Jim Blandy's avatar
Jim Blandy committed
170

171
  display = nargs >= 4 ? args[3] : Qnil;
Jim Blandy's avatar
Jim Blandy committed
172 173 174 175 176 177 178 179 180 181 182 183 184

  {
    register int i;
    for (i = 4; i < nargs; i++)
      {
	CHECK_STRING (args[i], i);
	new_argv[i - 3] = XSTRING (args[i])->data;
      }
    /* Program name is first command arg */
    new_argv[0] = XSTRING (args[0])->data;
    new_argv[i - 3] = 0;
  }

185
  filefd = open (XSTRING (infile)->data, O_RDONLY, 0);
Jim Blandy's avatar
Jim Blandy committed
186 187
  if (filefd < 0)
    {
188
      report_file_error ("Opening process input file", Fcons (infile, Qnil));
Jim Blandy's avatar
Jim Blandy committed
189 190 191
    }
  /* Search for program; barf if not found.  */
  openp (Vexec_path, args[0], "", &path, 1);
192
  if (NILP (path))
Jim Blandy's avatar
Jim Blandy committed
193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
    {
      close (filefd);
      report_file_error ("Searching for program", Fcons (args[0], Qnil));
    }
  new_argv[0] = XSTRING (path)->data;

  if (XTYPE (buffer) == Lisp_Int)
    fd[1] = open ("/dev/null", O_WRONLY), fd[0] = -1;
  else
    {
      pipe (fd);
#if 0
      /* Replaced by close_process_descs */
      set_exclusive_use (fd[0]);
#endif
    }

210 211 212 213 214 215 216 217
  /* Make sure that the child will be able to chdir to the current
     buffer's current directory.  We can't just have the child check
     for an error when it does the chdir, since it's in a vfork.  */
  current_dir = expand_and_dir_to_file (current_buffer->directory, Qnil);
  if (NILP (Ffile_accessible_directory_p (current_dir)))
    report_file_error ("Setting current directory",
		       Fcons (current_buffer->directory, Qnil));

Jim Blandy's avatar
Jim Blandy committed
218 219 220 221 222 223 224
  {
    /* child_setup must clobber environ in systems with true vfork.
       Protect it from permanent change.  */
    register char **save_environ = environ;
    register int fd1 = fd[1];

#if 0  /* Some systems don't have sigblock.  */
Jim Blandy's avatar
Jim Blandy committed
225
    mask = sigblock (sigmask (SIGCHLD));
Jim Blandy's avatar
Jim Blandy committed
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
#endif

    /* Record that we're about to create a synchronous process.  */
    synch_process_alive = 1;

    pid = vfork ();

    if (pid == 0)
      {
	if (fd[0] >= 0)
	  close (fd[0]);
#ifdef USG
        setpgrp ();
#else
        setpgrp (pid, pid);
#endif /* USG */
242
	child_setup (filefd, fd1, fd1, new_argv, 0, current_dir);
Jim Blandy's avatar
Jim Blandy committed
243 244 245 246 247 248
      }

#if 0
    /* Tell SIGCHLD handler to look for this pid.  */
    synch_process_pid = pid;
    /* Now let SIGCHLD come through.  */
Jim Blandy's avatar
Jim Blandy committed
249
    sigsetmask (mask);
Jim Blandy's avatar
Jim Blandy committed
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266
#endif

    environ = save_environ;

    close (filefd);
    close (fd1);
  }

  if (pid < 0)
    {
      close (fd[0]);
      report_file_error ("Doing vfork", Qnil);
    }

  if (XTYPE (buffer) == Lisp_Int)
    {
#ifndef subprocesses
267 268 269
      /* If Emacs has been built with asynchronous subprocess support,
	 we don't need to do this, I think because it will then have
	 the facilities for handling SIGCHLD.  */
Jim Blandy's avatar
Jim Blandy committed
270 271 272 273 274
      wait_without_blocking ();
#endif /* subprocesses */
      return Qnil;
    }

275 276 277
  synch_process_death = 0;
  synch_process_retcode = 0;

Jim Blandy's avatar
Jim Blandy committed
278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293
  record_unwind_protect (call_process_cleanup,
			 Fcons (make_number (fd[0]), make_number (pid)));


  if (XTYPE (buffer) == Lisp_Buffer)
    Fset_buffer (buffer);

  immediate_quit = 1;
  QUIT;

  {
    register int nread;

    while ((nread = read (fd[0], buf, sizeof buf)) > 0)
      {
	immediate_quit = 0;
294
	if (!NILP (buffer))
Jim Blandy's avatar
Jim Blandy committed
295
	  insert (buf, nread);
296
	if (!NILP (display) && INTERACTIVE)
Jim Blandy's avatar
Jim Blandy committed
297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334
	  redisplay_preserve_echo_area ();
	immediate_quit = 1;
	QUIT;
      }
  }

  /* Wait for it to terminate, unless it already has.  */
  wait_for_termination (pid);

  immediate_quit = 0;

  set_buffer_internal (old);

  unbind_to (count, Qnil);

  if (synch_process_death)
    return build_string (synch_process_death);
  return make_number (synch_process_retcode);
}
#endif

static void
delete_temp_file (name)
     Lisp_Object name;
{
  unlink (XSTRING (name)->data);
}

DEFUN ("call-process-region", Fcall_process_region, Scall_process_region,
  3, MANY, 0,
  "Send text from START to END to a synchronous process running PROGRAM.\n\
Delete the text if fourth arg DELETE is non-nil.\n\
Insert output in BUFFER before point; t means current buffer;\n\
 nil for BUFFER means discard it; 0 means discard and don't wait.\n\
Sixth arg DISPLAY non-nil means redisplay buffer as output is inserted.\n\
Remaining args are passed to PROGRAM at startup as command args.\n\
If BUFFER is nil, returns immediately with value nil.\n\
Otherwise waits for PROGRAM to terminate\n\
335
and returns a numeric exit status or a signal description string.\n\
336
If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.")
Jim Blandy's avatar
Jim Blandy committed
337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357
  (nargs, args)
     int nargs;
     register Lisp_Object *args;
{
  register Lisp_Object filename_string, start, end;
  char tempfile[20];
  int count = specpdl_ptr - specpdl;

#ifdef VMS
  strcpy (tempfile, "tmp:emacsXXXXXX.");
#else
  strcpy (tempfile, "/tmp/emacsXXXXXX");
#endif
  mktemp (tempfile);

  filename_string = build_string (tempfile);
  start = args[0];
  end = args[1];
  Fwrite_region (start, end, filename_string, Qnil, Qlambda);
  record_unwind_protect (delete_temp_file, filename_string);

358
  if (!NILP (args[3]))
Jim Blandy's avatar
Jim Blandy committed
359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
    Fdelete_region (start, end);

  args[3] = filename_string;
  Fcall_process (nargs - 2, args + 2);

  return unbind_to (count, Qnil);
}

#ifndef VMS /* VMS version is in vmsproc.c.  */

/* This is the last thing run in a newly forked inferior
   either synchronous or asynchronous.
   Copy descriptors IN, OUT and ERR as descriptors 0, 1 and 2.
   Initialize inferior's priority, pgrp, connected dir and environment.
   then exec another program based on new_argv.

   This function may change environ for the superior process.
   Therefore, the superior process must save and restore the value
   of environ around the vfork and the call to this function.

   ENV is the environment for the subprocess.

   SET_PGRP is nonzero if we should put the subprocess into a separate
382 383 384 385 386 387
   process group.  

   CURRENT_DIR is an elisp string giving the path of the current
   directory the subprocess should have.  Since we can't really signal
   a decent error from within the child, this should be verified as an
   executable directory by the parent.  */
Jim Blandy's avatar
Jim Blandy committed
388

389
child_setup (in, out, err, new_argv, set_pgrp, current_dir)
Jim Blandy's avatar
Jim Blandy committed
390 391 392
     int in, out, err;
     register char **new_argv;
     int set_pgrp;
393
     Lisp_Object current_dir;
Jim Blandy's avatar
Jim Blandy committed
394
{
395 396
  char **env;

Jim Blandy's avatar
Jim Blandy committed
397 398
  register int pid = getpid();

399 400 401 402 403
  {
    extern int emacs_priority;

    nice (- emacs_priority);
  }
Jim Blandy's avatar
Jim Blandy committed
404 405 406 407 408 409 410 411 412 413 414

#ifdef subprocesses
  /* Close Emacs's descriptors that this process should not have.  */
  close_process_descs ();
#endif

  /* Note that use of alloca is always safe here.  It's obvious for systems
     that do not have true vfork or that have true (stack) alloca.
     If using vfork and C_ALLOCA it is safe because that changes
     the superior's static variables as if the superior had done alloca
     and will be cleaned up in the usual way.  */
415 416 417
  {
    register unsigned char *temp;
    register int i;
Jim Blandy's avatar
Jim Blandy committed
418

419 420 421 422 423 424 425 426 427 428 429 430 431 432
    i = XSTRING (current_dir)->size;
    temp = (unsigned char *) alloca (i + 2);
    bcopy (XSTRING (current_dir)->data, temp, i);
    if (temp[i - 1] != '/') temp[i++] = '/';
    temp[i] = 0;

    /* We can't signal an Elisp error here; we're in a vfork.  Since
       the callers check the current directory before forking, this
       should only return an error if the directory's permissions
       are changed between the check and this chdir, but we should
       at least check.  */
    if (chdir (temp) < 0)
      exit (errno);
  }
Jim Blandy's avatar
Jim Blandy committed
433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449

  /* Set `env' to a vector of the strings in Vprocess_environment.  */
  {
    register Lisp_Object tem;
    register char **new_env;
    register int new_length;

    new_length = 0;
    for (tem = Vprocess_environment;
	 (XTYPE (tem) == Lisp_Cons
	  && XTYPE (XCONS (tem)->car) == Lisp_String);
	 tem = XCONS (tem)->cdr)
      new_length++;

    /* new_length + 1 to include terminating 0 */
    env = new_env = (char **) alloca ((new_length + 1) * sizeof (char *));

450
    /* Copy the Vprocess_alist strings into new_env.  */
Jim Blandy's avatar
Jim Blandy committed
451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469
    for (tem = Vprocess_environment;
	 (XTYPE (tem) == Lisp_Cons
	  && XTYPE (XCONS (tem)->car) == Lisp_String);
	 tem = XCONS (tem)->cdr)
      *new_env++ = (char *) XSTRING (XCONS (tem)->car)->data;
    *new_env = 0;
  }

  close (0);
  close (1);
  close (2);

  dup2 (in, 0);
  dup2 (out, 1);
  dup2 (err, 2);
  close (in);
  close (out);
  close (err);

470 471 472 473 474
#ifdef USG
  setpgrp ();			/* No arguments but equivalent in this case */
#else
  setpgrp (pid, pid);
#endif /* USG */
Jim Blandy's avatar
Jim Blandy committed
475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
  setpgrp_of_tty (pid);

#ifdef vipc
  something missing here;
#endif /* vipc */

  /* execvp does not accept an environment arg so the only way
     to pass this environment is to set environ.  Our caller
     is responsible for restoring the ambient value of environ.  */
  environ = env;
  execvp (new_argv[0], new_argv);

  write (1, "Couldn't exec the program ", 26);
  write (1, new_argv[0], strlen (new_argv[0]));
  _exit (1);
}

492 493 494 495 496 497 498 499 500 501 502 503
static int
getenv_internal (var, varlen, value, valuelen)
     char *var;
     int varlen;
     char **value;
     int *valuelen;
{
  Lisp_Object scan;

  for (scan = Vprocess_environment; CONSP (scan); scan = XCONS (scan)->cdr)
    {
      Lisp_Object entry = XCONS (scan)->car;
504
      
505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
      if (XTYPE (entry) == Lisp_String
	  && XSTRING (entry)->size > varlen
	  && XSTRING (entry)->data[varlen] == '='
	  && ! bcmp (XSTRING (entry)->data, var, varlen))
	{
	  *value    = (char *) XSTRING (entry)->data + (varlen + 1);
	  *valuelen = XSTRING (entry)->size - (varlen + 1);
	  return 1;
	}
    }

  return 0;
}

DEFUN ("getenv", Fgetenv, Sgetenv, 1, 2, 0,
  "Return the value of environment variable VAR, as a string.\n\
VAR should be a string.  Value is nil if VAR is undefined in the environment.\n\
This function consults the variable ``process-environment'' for its value.")
  (var)
     Lisp_Object var;
{
  char *value;
  int valuelen;

  CHECK_STRING (var, 0);
  if (getenv_internal (XSTRING (var)->data, XSTRING (var)->size,
		       &value, &valuelen))
    return make_string (value, valuelen);
  else
    return Qnil;
}

/* A version of getenv that consults process_environment, easily
538
   callable from C.  */
539 540
char *
egetenv (var)
541
     char *var;
542 543 544 545 546 547 548 549 550 551
{
  char *value;
  int valuelen;

  if (getenv_internal (var, strlen (var), &value, &valuelen))
    return value;
  else
    return 0;
}

Jim Blandy's avatar
Jim Blandy committed
552 553 554 555 556 557
#endif /* not VMS */

init_callproc ()
{
  register char * sh;
  register char **envp;
558 559 560 561 562 563 564 565 566
  Lisp_Object tempdir;

  {
    char *data_dir = egetenv ("EMACSDATA");
    
    Vdata_directory =
      Ffile_name_as_directory
	(build_string (data_dir ? data_dir : PATH_DATA));
  }
Jim Blandy's avatar
Jim Blandy committed
567

568 569 570
  /* Check the EMACSPATH environment variable, defaulting to the
     PATH_EXEC path from paths.h.  */
  Vexec_path = decode_env_path ("EMACSPATH", PATH_EXEC);
Jim Blandy's avatar
Jim Blandy committed
571 572 573
  Vexec_directory = Ffile_name_as_directory (Fcar (Vexec_path));
  Vexec_path = nconc2 (decode_env_path ("PATH", ""), Vexec_path);

574 575
  tempdir = Fdirectory_file_name (Vexec_directory);
  if (access (XSTRING (tempdir)->data, 0) < 0)
Jim Blandy's avatar
Jim Blandy committed
576
    {
577
      printf ("Warning: arch-dependent data dir (%s) does not exist.\n",
Jim Blandy's avatar
Jim Blandy committed
578 579 580 581
	      XSTRING (Vexec_directory)->data);
      sleep (2);
    }

582 583 584 585 586 587 588 589
  tempdir = Fdirectory_file_name (Vdata_directory);
  if (access (XSTRING (tempdir)->data, 0) < 0)
    {
      printf ("Warning: arch-independent data dir (%s) does not exist.\n",
	      XSTRING (Vdata_directory)->data);
      sleep (2);
    }

Jim Blandy's avatar
Jim Blandy committed
590 591 592
#ifdef VMS
  Vshell_file_name = build_string ("*dcl*");
#else
593
  sh = (char *) getenv ("SHELL");
Jim Blandy's avatar
Jim Blandy committed
594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
  Vshell_file_name = build_string (sh ? sh : "/bin/sh");
#endif

  Vprocess_environment = Qnil;
#ifndef CANNOT_DUMP
  if (initialized)
#endif
    for (envp = environ; *envp; envp++)
      Vprocess_environment = Fcons (build_string (*envp),
				    Vprocess_environment);
}

syms_of_callproc ()
{
  DEFVAR_LISP ("shell-file-name", &Vshell_file_name,
    "*File name to load inferior shells from.\n\
Initialized from the SHELL environment variable.");

  DEFVAR_LISP ("exec-path", &Vexec_path,
    "*List of directories to search programs to run in subprocesses.\n\
Each element is a string (directory name) or nil (try default directory).");

  DEFVAR_LISP ("exec-directory", &Vexec_directory,
617 618 619 620 621 622
    "Directory of architecture-dependent files that come with GNU Emacs,\n\
especially executable programs intended for Emacs to invoke.");

  DEFVAR_LISP ("data-directory", &Vdata_directory,
    "Directory of architecture-independent files that come with GNU Emacs,\n\
intended for Emacs to use.");
Jim Blandy's avatar
Jim Blandy committed
623 624

  DEFVAR_LISP ("process-environment", &Vprocess_environment,
625 626 627 628
    "List of environment variables for subprocesses to inherit.\n\
Each element should be a string of the form ENVVARNAME=VALUE.\n\
The environment which Emacs inherits is placed in this variable\n\
when Emacs starts.");
Jim Blandy's avatar
Jim Blandy committed
629 630 631 632

#ifndef VMS
  defsubr (&Scall_process);
#endif
633
  defsubr (&Sgetenv);
634
  defsubr (&Scall_process_region);
Jim Blandy's avatar
Jim Blandy committed
635
}