process.c 219 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Asynchronous subprocess control for GNU Emacs.
2
   Copyright (C) 1985, 1986, 1987, 1988, 1993, 1994, 1995,
3
		 1996, 1998, 1999, 2001, 2002, 2003, 2004,
Glenn Morris's avatar
Glenn Morris committed
4
		 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7

This file is part of GNU Emacs.

8
GNU Emacs is free software: you can redistribute it and/or modify
Jim Blandy's avatar
Jim Blandy committed
9
it under the terms of the GNU General Public License as published by
10 11
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Jim Blandy's avatar
Jim Blandy committed
12 13 14 15 16 17 18

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
19
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Jim Blandy's avatar
Jim Blandy committed
20 21


22
#include <config.h>
23
#include <signal.h>
Jim Blandy's avatar
Jim Blandy committed
24 25 26 27 28 29
#include <stdio.h>
#include <errno.h>
#include <setjmp.h>
#include <sys/types.h>		/* some typedefs are used in sys/file.h */
#include <sys/file.h>
#include <sys/stat.h>
30
#include <setjmp.h>
31 32 33
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
34
#include <stdlib.h>
35

Richard M. Stallman's avatar
Richard M. Stallman committed
36 37 38
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
39 40
#include <fcntl.h>

41 42 43
/* Only MS-DOS does not define `subprocesses'.  */
#ifdef subprocesses

Jim Blandy's avatar
Jim Blandy committed
44 45 46 47
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
48 49

/* Are local (unix) sockets supported?  */
50
#if defined (HAVE_SYS_UN_H)
51 52 53 54 55 56 57 58
#if !defined (AF_LOCAL) && defined (AF_UNIX)
#define AF_LOCAL AF_UNIX
#endif
#ifdef AF_LOCAL
#define HAVE_LOCAL_SOCKETS
#include <sys/un.h>
#endif
#endif
Jim Blandy's avatar
Jim Blandy committed
59

Dan Nicolaescu's avatar
Dan Nicolaescu committed
60
#if defined(HAVE_SYS_IOCTL_H)
Jim Blandy's avatar
Jim Blandy committed
61
#include <sys/ioctl.h>
62 63 64
#if defined(HAVE_NET_IF_H)
#include <net/if.h>
#endif /* HAVE_NET_IF_H */
Dan Nicolaescu's avatar
Dan Nicolaescu committed
65
#endif /* HAVE_SYS_IOCTL_H */
Jim Blandy's avatar
Jim Blandy committed
66 67 68 69 70

#ifdef NEED_BSDTTY
#include <bsdtty.h>
#endif

Dave Love's avatar
Dave Love committed
71 72 73
#ifdef HAVE_SYS_WAIT
#include <sys/wait.h>
#endif
Jim Blandy's avatar
Jim Blandy committed
74

75 76 77 78 79 80
#ifdef HAVE_RES_INIT
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#endif

81 82 83 84
#ifdef HAVE_UTIL_H
#include <util.h>
#endif

85 86
#endif	/* subprocesses */

87
#include "lisp.h"
Jim Blandy's avatar
Jim Blandy committed
88
#include "systime.h"
89
#include "systty.h"
Jim Blandy's avatar
Jim Blandy committed
90 91 92

#include "window.h"
#include "buffer.h"
93
#include "character.h"
Karl Heuer's avatar
Karl Heuer committed
94
#include "coding.h"
Jim Blandy's avatar
Jim Blandy committed
95
#include "process.h"
96
#include "frame.h"
Jim Blandy's avatar
Jim Blandy committed
97 98 99
#include "termhooks.h"
#include "termopts.h"
#include "commands.h"
100
#include "keyboard.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
101
#include "blockinput.h"
Andreas Schwab's avatar
Andreas Schwab committed
102
#include "dispextern.h"
Kenichi Handa's avatar
Kenichi Handa committed
103
#include "composite.h"
Gerd Moellmann's avatar
Gerd Moellmann committed
104
#include "atimer.h"
105 106 107
#include "sysselect.h"
#include "syssignal.h"
#include "syswait.h"
Ted Zlatanov's avatar
Ted Zlatanov committed
108 109 110
#ifdef HAVE_GNUTLS
#include "gnutls.h"
#endif
Jim Blandy's avatar
Jim Blandy committed
111

112 113 114
#if defined (USE_GTK) || defined (HAVE_GCONF)
#include "xgselect.h"
#endif /* defined (USE_GTK) || defined (HAVE_GCONF) */
115 116 117
#ifdef HAVE_NS
#include "nsterm.h"
#endif
118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
extern int timers_run;

Lisp_Object Qeuid, Qegid, Qcomm, Qstate, Qppid, Qpgrp, Qsess, Qttname, Qtpgid;
Lisp_Object Qminflt, Qmajflt, Qcminflt, Qcmajflt, Qutime, Qstime, Qcstime;
Lisp_Object Qcutime, Qpri, Qnice, Qthcount, Qstart, Qvsize, Qrss, Qargs;
Lisp_Object Quser, Qgroup, Qetime, Qpcpu, Qpmem, Qtime, Qctime;
Lisp_Object QCname, QCtype;

/* Non-zero if keyboard input is on hold, zero otherwise.  */

static int kbd_is_on_hold;

/* Nonzero means delete a process right away if it exits.  */
static int delete_exited_processes;

/* Nonzero means don't run process sentinels.  This is used
   when exiting.  */
int inhibit_sentinels;

137 138
#ifdef subprocesses

139
Lisp_Object Qprocessp;
Kim F. Storm's avatar
Kim F. Storm committed
140
Lisp_Object Qrun, Qstop, Qsignal;
141
Lisp_Object Qopen, Qclosed, Qconnect, Qfailed, Qlisten;
Stefan Monnier's avatar
Stefan Monnier committed
142
Lisp_Object Qlocal, Qipv4, Qdatagram, Qseqpacket;
143
Lisp_Object Qreal, Qnetwork, Qserial;
Kim F. Storm's avatar
Kim F. Storm committed
144 145 146
#ifdef AF_INET6
Lisp_Object Qipv6;
#endif
147 148 149
Lisp_Object QCport, QCspeed, QCprocess;
Lisp_Object QCbytesize, QCstopbits, QCparity, Qodd, Qeven;
Lisp_Object QCflowcontrol, Qhw, Qsw, QCsummary;
150
Lisp_Object QCbuffer, QChost, QCservice;
151
Lisp_Object QClocal, QCremote, QCcoding;
152
Lisp_Object QCserver, QCnowait, QCnoquery, QCstop;
153
Lisp_Object QCsentinel, QClog, QCoptions, QCplist;
154
Lisp_Object Qlast_nonmenu_event;
155 156 157 158
/* QCfamily is declared and initialized in xfaces.c,
   QCfilter in keyboard.c.  */
extern Lisp_Object QCfamily, QCfilter;

Jim Blandy's avatar
Jim Blandy committed
159 160
/* Qexit is declared and initialized in eval.c.  */

161 162 163 164 165
/* QCfamily is defined in xfaces.c.  */
extern Lisp_Object QCfamily;
/* QCfilter is defined in keyboard.c.  */
extern Lisp_Object QCfilter;

166 167 168 169
#define NETCONN_P(p) (EQ (XPROCESS (p)->type, Qnetwork))
#define NETCONN1_P(p) (EQ ((p)->type, Qnetwork))
#define SERIALCONN_P(p) (EQ (XPROCESS (p)->type, Qserial))
#define SERIALCONN1_P(p) (EQ ((p)->type, Qserial))
Jim Blandy's avatar
Jim Blandy committed
170 171 172 173 174 175 176 177 178 179 180

/* Define first descriptor number available for subprocesses.  */
#define FIRST_PROC_DESC 3

/* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
   testing SIGCHLD.  */

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

181
extern const char *get_operating_system_release (void);
182

183 184 185 186
/* From sysdep.c or w32.c  */
extern int serial_open (char *port);
extern void serial_configure (struct Lisp_Process *p, Lisp_Object contact);

187 188 189 190
#ifndef HAVE_H_ERRNO
extern int h_errno;
#endif

Jim Blandy's avatar
Jim Blandy committed
191 192
/* t means use pty, nil means use a pipe,
   maybe other values to come.  */
193
static Lisp_Object Vprocess_connection_type;
Jim Blandy's avatar
Jim Blandy committed
194

195 196
/* These next two vars are non-static since sysdep.c uses them in the
   emulation of `select'.  */
Jim Blandy's avatar
Jim Blandy committed
197
/* Number of events of change of status of a process.  */
198
int process_tick;
Jim Blandy's avatar
Jim Blandy committed
199
/* Number of events for which the user or sentinel has been notified.  */
200
int update_tick;
Jim Blandy's avatar
Jim Blandy committed
201

202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219
/* Define NON_BLOCKING_CONNECT if we can support non-blocking connects.  */

#ifdef BROKEN_NON_BLOCKING_CONNECT
#undef NON_BLOCKING_CONNECT
#else
#ifndef NON_BLOCKING_CONNECT
#ifdef HAVE_SELECT
#if defined (HAVE_GETPEERNAME) || defined (GNU_LINUX)
#if defined (O_NONBLOCK) || defined (O_NDELAY)
#if defined (EWOULDBLOCK) || defined (EINPROGRESS)
#define NON_BLOCKING_CONNECT
#endif /* EWOULDBLOCK || EINPROGRESS */
#endif /* O_NONBLOCK || O_NDELAY */
#endif /* HAVE_GETPEERNAME || GNU_LINUX */
#endif /* HAVE_SELECT */
#endif /* NON_BLOCKING_CONNECT */
#endif /* BROKEN_NON_BLOCKING_CONNECT */

220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236
/* Define DATAGRAM_SOCKETS if datagrams can be used safely on
   this system.  We need to read full packets, so we need a
   "non-destructive" select.  So we require either native select,
   or emulation of select using FIONREAD.  */

#ifdef BROKEN_DATAGRAM_SOCKETS
#undef DATAGRAM_SOCKETS
#else
#ifndef DATAGRAM_SOCKETS
#if defined (HAVE_SELECT) || defined (FIONREAD)
#if defined (HAVE_SENDTO) && defined (HAVE_RECVFROM) && defined (EMSGSIZE)
#define DATAGRAM_SOCKETS
#endif /* HAVE_SENDTO && HAVE_RECVFROM && EMSGSIZE */
#endif /* HAVE_SELECT || FIONREAD */
#endif /* DATAGRAM_SOCKETS */
#endif /* BROKEN_DATAGRAM_SOCKETS */

Stefan Monnier's avatar
Stefan Monnier committed
237 238 239 240
#if defined HAVE_LOCAL_SOCKETS && defined DATAGRAM_SOCKETS
# define HAVE_SEQPACKET
#endif

Kenichi Handa's avatar
Kenichi Handa committed
241 242 243 244 245 246 247 248 249 250 251
#if !defined (ADAPTIVE_READ_BUFFERING) && !defined (NO_ADAPTIVE_READ_BUFFERING)
#ifdef EMACS_HAS_USECS
#define ADAPTIVE_READ_BUFFERING
#endif
#endif

#ifdef ADAPTIVE_READ_BUFFERING
#define READ_OUTPUT_DELAY_INCREMENT 10000
#define READ_OUTPUT_DELAY_MAX       (READ_OUTPUT_DELAY_INCREMENT * 5)
#define READ_OUTPUT_DELAY_MAX_MAX   (READ_OUTPUT_DELAY_INCREMENT * 7)

252 253
/* Number of processes which have a non-zero read_output_delay,
   and therefore might be delayed for adaptive read buffering.  */
Kenichi Handa's avatar
Kenichi Handa committed
254 255 256

static int process_output_delay_count;

257
/* Non-zero if any process has non-nil read_output_skip.  */
Kenichi Handa's avatar
Kenichi Handa committed
258 259 260 261 262

static int process_output_skip;

/* Non-nil means to delay reading process output to improve buffering.
   A value of t means that delay is reset after each send, any other
263 264
   non-nil value does not reset the delay.  A value of nil disables
   adaptive read buffering completely.  */
Kenichi Handa's avatar
Kenichi Handa committed
265 266 267 268 269
static Lisp_Object Vprocess_adaptive_read_buffering;
#else
#define process_output_delay_count 0
#endif

270 271 272 273 274
static int keyboard_bit_set (SELECT_TYPE *);
static void deactivate_process (Lisp_Object);
static void status_notify (struct Lisp_Process *);
static int read_process_output (Lisp_Object, int);
static void create_pty (Lisp_Object);
275

276
/* If we support a window system, turn on the code to poll periodically
277
   to detect C-g.  It isn't actually used when doing interrupt input.  */
278
#ifdef HAVE_WINDOW_SYSTEM
279 280 281
#define POLL_FOR_INPUT
#endif

282 283
static Lisp_Object get_process (register Lisp_Object name);
static void exec_sentinel (Lisp_Object proc, Lisp_Object reason);
284

285 286 287 288
/* Mask of bits indicating the descriptors that we wait for input on.  */

static SELECT_TYPE input_wait_mask;

289
/* Mask that excludes keyboard input descriptor(s).  */
290 291 292

static SELECT_TYPE non_keyboard_wait_mask;

293
/* Mask that excludes process input descriptor(s).  */
294 295 296

static SELECT_TYPE non_process_wait_mask;

297
/* Mask for selecting for write.  */
298

299
static SELECT_TYPE write_mask;
300

301
#ifdef NON_BLOCKING_CONNECT
302 303 304 305 306 307 308 309 310
/* Mask of bits indicating the descriptors that we wait for connect to
   complete on.  Once they complete, they are removed from this mask
   and added to the input_wait_mask and non_keyboard_wait_mask.  */

static SELECT_TYPE connect_wait_mask;

/* Number of bits set in connect_wait_mask.  */
static int num_pending_connects;

311
#define IF_NON_BLOCKING_CONNECT(s) s
312
#else  /* NON_BLOCKING_CONNECT */
313
#define IF_NON_BLOCKING_CONNECT(s)
314
#endif	/* NON_BLOCKING_CONNECT */
315

316 317 318
/* The largest descriptor currently in use for a process object.  */
static int max_process_desc;

319 320
/* The largest descriptor currently in use for input.  */
static int max_input_desc;
321

Jim Blandy's avatar
Jim Blandy committed
322
/* Indexed by descriptor, gives the process (if any) for that descriptor */
323
Lisp_Object chan_process[MAXDESC];
Jim Blandy's avatar
Jim Blandy committed
324 325

/* Alist of elements (NAME . PROCESS) */
326
Lisp_Object Vprocess_alist;
Jim Blandy's avatar
Jim Blandy committed
327 328 329 330 331 332 333

/* Buffered-ahead input char from process, indexed by channel.
   -1 means empty (no char is buffered).
   Used on sys V where the only way to tell if there is any
   output from the process is to read at least one char.
   Always -1 on systems that support FIONREAD.  */

334 335
/* Don't make static; need to access externally.  */
int proc_buffered_char[MAXDESC];
336

Karl Heuer's avatar
Karl Heuer committed
337
/* Table of `struct coding-system' for each process.  */
338 339
static struct coding_system *proc_decode_coding_system[MAXDESC];
static struct coding_system *proc_encode_coding_system[MAXDESC];
Karl Heuer's avatar
Karl Heuer committed
340

341 342 343 344 345 346 347
#ifdef DATAGRAM_SOCKETS
/* Table of `partner address' for datagram sockets.  */
struct sockaddr_and_len {
  struct sockaddr *sa;
  int len;
} datagram_address[MAXDESC];
#define DATAGRAM_CHAN_P(chan)	(datagram_address[chan].sa != 0)
348
#define DATAGRAM_CONN_P(proc)	(PROCESSP (proc) && datagram_address[XPROCESS (proc)->infd].sa != 0)
349 350 351 352 353
#else
#define DATAGRAM_CHAN_P(chan)	(0)
#define DATAGRAM_CONN_P(proc)	(0)
#endif

Richard M. Stallman's avatar
Richard M. Stallman committed
354 355
/* Maximum number of bytes to send to a pty without an eof.  */
static int pty_max_bytes;
356

357
#ifdef HAVE_PTYS
Dave Love's avatar
Dave Love committed
358 359 360
#ifdef HAVE_PTY_H
#include <pty.h>
#endif
361
/* The file name of the pty opened by allocate_pty.  */
362 363

static char pty_name[24];
364
#endif
365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448


struct fd_callback_data
{
  fd_callback func;
  void *data;
#define FOR_READ  1
#define FOR_WRITE 2
  int condition; /* mask of the defines above.  */
} fd_callback_info[MAXDESC];


/* Add a file descriptor FD to be monitored for when read is possible.
   When read is possible, call FUNC with argument DATA.  */

void
add_read_fd (int fd, fd_callback func, void *data)
{
  xassert (fd < MAXDESC);
  add_keyboard_wait_descriptor (fd);

  fd_callback_info[fd].func = func;
  fd_callback_info[fd].data = data;
  fd_callback_info[fd].condition |= FOR_READ;
}

/* Stop monitoring file descriptor FD for when read is possible.  */

void
delete_read_fd (int fd)
{
  xassert (fd < MAXDESC);
  delete_keyboard_wait_descriptor (fd);

  fd_callback_info[fd].condition &= ~FOR_READ;
  if (fd_callback_info[fd].condition == 0)
    {
      fd_callback_info[fd].func = 0;
      fd_callback_info[fd].data = 0;
    }
}

/* Add a file descriptor FD to be monitored for when write is possible.
   When write is possible, call FUNC with argument DATA.  */

void
add_write_fd (int fd, fd_callback func, void *data)
{
  xassert (fd < MAXDESC);
  FD_SET (fd, &write_mask);
  if (fd > max_input_desc)
    max_input_desc = fd;

  fd_callback_info[fd].func = func;
  fd_callback_info[fd].data = data;
  fd_callback_info[fd].condition |= FOR_WRITE;
}

/* Stop monitoring file descriptor FD for when write is possible.  */

void
delete_write_fd (int fd)
{
  int lim = max_input_desc;

  xassert (fd < MAXDESC);
  FD_CLR (fd, &write_mask);
  fd_callback_info[fd].condition &= ~FOR_WRITE;
  if (fd_callback_info[fd].condition == 0)
    {
      fd_callback_info[fd].func = 0;
      fd_callback_info[fd].data = 0;

      if (fd == max_input_desc)
        for (fd = lim; fd >= 0; fd--)
          if (FD_ISSET (fd, &input_wait_mask) || FD_ISSET (fd, &write_mask))
            {
              max_input_desc = fd;
              break;
            }
      
    }
}

Jim Blandy's avatar
Jim Blandy committed
449 450 451 452

/* Compute the Lisp form of the process status, p->status, from
   the numeric status that was returned by `wait'.  */

453
static Lisp_Object status_convert (int);
454

455
static void
456
update_status (struct Lisp_Process *p)
Jim Blandy's avatar
Jim Blandy committed
457
{
458
  eassert (p->raw_status_new);
459
  p->status = status_convert (p->raw_status);
460
  p->raw_status_new = 0;
Jim Blandy's avatar
Jim Blandy committed
461 462
}

463
/*  Convert a process status word in Unix format to
Jim Blandy's avatar
Jim Blandy committed
464 465
    the list that we use internally.  */

466
static Lisp_Object
467
status_convert (int w)
Jim Blandy's avatar
Jim Blandy committed
468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483
{
  if (WIFSTOPPED (w))
    return Fcons (Qstop, Fcons (make_number (WSTOPSIG (w)), Qnil));
  else if (WIFEXITED (w))
    return Fcons (Qexit, Fcons (make_number (WRETCODE (w)),
				WCOREDUMP (w) ? Qt : Qnil));
  else if (WIFSIGNALED (w))
    return Fcons (Qsignal, Fcons (make_number (WTERMSIG (w)),
				  WCOREDUMP (w) ? Qt : Qnil));
  else
    return Qrun;
}

/* Given a status-list, extract the three pieces of information
   and store them individually through the three pointers.  */

484
static void
485
decode_status (Lisp_Object l, Lisp_Object *symbol, int *code, int *coredump)
Jim Blandy's avatar
Jim Blandy committed
486 487 488
{
  Lisp_Object tem;

489
  if (SYMBOLP (l))
Jim Blandy's avatar
Jim Blandy committed
490 491 492 493 494 495 496
    {
      *symbol = l;
      *code = 0;
      *coredump = 0;
    }
  else
    {
497 498 499 500
      *symbol = XCAR (l);
      tem = XCDR (l);
      *code = XFASTINT (XCAR (tem));
      tem = XCDR (tem);
Jim Blandy's avatar
Jim Blandy committed
501 502 503 504 505 506
      *coredump = !NILP (tem);
    }
}

/* Return a string describing a process status list.  */

507
static Lisp_Object
508
status_message (struct Lisp_Process *p)
Jim Blandy's avatar
Jim Blandy committed
509
{
510
  Lisp_Object status = p->status;
Jim Blandy's avatar
Jim Blandy committed
511 512 513 514 515 516 517 518
  Lisp_Object symbol;
  int code, coredump;
  Lisp_Object string, string2;

  decode_status (status, &symbol, &code, &coredump);

  if (EQ (symbol, Qsignal) || EQ (symbol, Qstop))
    {
519
      char *signame;
520
      synchronize_system_messages_locale ();
521
      signame = strsignal (code);
522
      if (signame == 0)
523 524 525 526 527 528 529 530 531
	string = build_string ("unknown");
      else
	{
	  int c1, c2;

	  string = make_unibyte_string (signame, strlen (signame));
	  if (! NILP (Vlocale_coding_system))
	    string = (code_convert_string_norecord
		      (string, Vlocale_coding_system, 0));
532
	  c1 = STRING_CHAR ((char *) SDATA (string));
533 534
	  c2 = DOWNCASE (c1);
	  if (c1 != c2)
535
	    Faset (string, make_number (0), make_number (c2));
536
	}
Jim Blandy's avatar
Jim Blandy committed
537 538 539 540 541
      string2 = build_string (coredump ? " (core dumped)\n" : "\n");
      return concat2 (string, string2);
    }
  else if (EQ (symbol, Qexit))
    {
542 543
      if (NETCONN1_P (p))
	return build_string (code == 0 ? "deleted\n" : "connection broken by remote peer\n");
Jim Blandy's avatar
Jim Blandy committed
544 545
      if (code == 0)
	return build_string ("finished\n");
546
      string = Fnumber_to_string (make_number (code));
Jim Blandy's avatar
Jim Blandy committed
547
      string2 = build_string (coredump ? " (core dumped)\n" : "\n");
548 549
      return concat3 (build_string ("exited abnormally with code "),
		      string, string2);
Jim Blandy's avatar
Jim Blandy committed
550
    }
551 552 553 554
  else if (EQ (symbol, Qfailed))
    {
      string = Fnumber_to_string (make_number (code));
      string2 = build_string ("\n");
555 556
      return concat3 (build_string ("failed with code "),
		      string, string2);
557
    }
Jim Blandy's avatar
Jim Blandy committed
558 559 560 561 562 563
  else
    return Fcopy_sequence (Fsymbol_name (symbol));
}

#ifdef HAVE_PTYS

564 565 566 567 568
/* Open an available pty, returning a file descriptor.
   Return -1 on failure.
   The file name of the terminal corresponding to the pty
   is left in the variable pty_name.  */

569
static int
570
allocate_pty (void)
Jim Blandy's avatar
Jim Blandy committed
571
{
Andreas Schwab's avatar
Andreas Schwab committed
572
  register int c, i;
Jim Blandy's avatar
Jim Blandy committed
573 574 575 576 577 578 579 580 581
  int fd;

#ifdef PTY_ITERATION
  PTY_ITERATION
#else
  for (c = FIRST_PTY_LETTER; c <= 'z'; c++)
    for (i = 0; i < 16; i++)
#endif
      {
582
	struct stat stb;	/* Used in some PTY_OPEN.  */
Jim Blandy's avatar
Jim Blandy committed
583 584 585 586 587 588
#ifdef PTY_NAME_SPRINTF
	PTY_NAME_SPRINTF
#else
	sprintf (pty_name, "/dev/pty%c%x", c, i);
#endif /* no PTY_NAME_SPRINTF */

589 590 591
#ifdef PTY_OPEN
	PTY_OPEN;
#else /* no PTY_OPEN */
592 593 594 595 596 597 598
	{
	  { /* Some systems name their pseudoterminals so that there are gaps in
	       the usual sequence - for example, on HP9000/S700 systems, there
	       are no pseudoterminals with names ending in 'f'.  So we wait for
	       three failures in a row before deciding that we've reached the
	       end of the ptys.  */
	    int failed_count = 0;
599

600 601 602 603 604 605 606 607
	    if (stat (pty_name, &stb) < 0)
	      {
		failed_count++;
		if (failed_count >= 3)
		  return -1;
	      }
	    else
	      failed_count = 0;
Jim Blandy's avatar
Jim Blandy committed
608
	  }
609 610 611 612 613 614
#  ifdef O_NONBLOCK
	  fd = emacs_open (pty_name, O_RDWR | O_NONBLOCK, 0);
#  else
	  fd = emacs_open (pty_name, O_RDWR | O_NDELAY, 0);
#  endif
	}
615
#endif /* no PTY_OPEN */
Jim Blandy's avatar
Jim Blandy committed
616 617 618 619 620 621 622 623

	if (fd >= 0)
	  {
	    /* check to make certain that both sides are available
	       this avoids a nasty yet stupid bug in rlogins */
#ifdef PTY_TTY_NAME_SPRINTF
	    PTY_TTY_NAME_SPRINTF
#else
624
	    sprintf (pty_name, "/dev/tty%c%x", c, i);
Jim Blandy's avatar
Jim Blandy committed
625 626 627
#endif /* no PTY_TTY_NAME_SPRINTF */
	    if (access (pty_name, 6) != 0)
	      {
628
		emacs_close (fd);
629
# ifndef __sgi
Jim Blandy's avatar
Jim Blandy committed
630
		continue;
631
# else
Jim Blandy's avatar
Jim Blandy committed
632
		return -1;
633
# endif /* __sgi */
Jim Blandy's avatar
Jim Blandy committed
634 635 636 637 638 639 640 641 642
	      }
	    setup_pty (fd);
	    return fd;
	  }
      }
  return -1;
}
#endif /* HAVE_PTYS */

643
static Lisp_Object
644
make_process (Lisp_Object name)
Jim Blandy's avatar
Jim Blandy committed
645 646 647 648 649 650
{
  register Lisp_Object val, tem, name1;
  register struct Lisp_Process *p;
  char suffix[10];
  register int i;

651
  p = allocate_process ();
652

653 654 655 656
  p->infd = -1;
  p->outfd = -1;
  p->tick = 0;
  p->update_tick = 0;
657
  p->pid = 0;
Miles Bader's avatar
Miles Bader committed
658
  p->pty_flag = 0;
659
  p->raw_status_new = 0;
Jim Blandy's avatar
Jim Blandy committed
660 661
  p->status = Qrun;
  p->mark = Fmake_marker ();
662
  p->kill_without_query = 0;
Jim Blandy's avatar
Jim Blandy committed
663

Kenichi Handa's avatar
Kenichi Handa committed
664
#ifdef ADAPTIVE_READ_BUFFERING
665 666 667
  p->adaptive_read_buffering = 0;
  p->read_output_delay = 0;
  p->read_output_skip = 0;
Kenichi Handa's avatar
Kenichi Handa committed
668 669
#endif

Ted Zlatanov's avatar
Ted Zlatanov committed
670 671 672 673
#ifdef HAVE_GNUTLS
  p->gnutls_initstage = GNUTLS_STAGE_EMPTY;
#endif

Jim Blandy's avatar
Jim Blandy committed
674 675 676 677 678 679 680 681 682 683 684 685
  /* If name is already in use, modify it until it is unused.  */

  name1 = name;
  for (i = 1; ; i++)
    {
      tem = Fget_process (name1);
      if (NILP (tem)) break;
      sprintf (suffix, "<%d>", i);
      name1 = concat2 (name, build_string (suffix));
    }
  name = name1;
  p->name = name;
686
  XSETPROCESS (val, p);
Jim Blandy's avatar
Jim Blandy committed
687 688 689 690
  Vprocess_alist = Fcons (Fcons (name, val), Vprocess_alist);
  return val;
}

691
static void
692
remove_process (register Lisp_Object proc)
Jim Blandy's avatar
Jim Blandy committed
693 694 695 696 697 698 699 700
{
  register Lisp_Object pair;

  pair = Frassq (proc, Vprocess_alist);
  Vprocess_alist = Fdelq (pair, Vprocess_alist);

  deactivate_process (proc);
}
701

Jim Blandy's avatar
Jim Blandy committed
702 703

DEFUN ("processp", Fprocessp, Sprocessp, 1, 1, 0,
704
       doc: /* Return t if OBJECT is a process.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
705
  (Lisp_Object object)
Jim Blandy's avatar
Jim Blandy committed
706
{
707
  return PROCESSP (object) ? Qt : Qnil;
Jim Blandy's avatar
Jim Blandy committed
708 709 710
}

DEFUN ("get-process", Fget_process, Sget_process, 1, 1, 0,
711
       doc: /* Return the process named NAME, or nil if there is none.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
712
  (register Lisp_Object name)
Jim Blandy's avatar
Jim Blandy committed
713
{
714
  if (PROCESSP (name))
Jim Blandy's avatar
Jim Blandy committed
715
    return name;
716
  CHECK_STRING (name);
Jim Blandy's avatar
Jim Blandy committed
717 718 719
  return Fcdr (Fassoc (name, Vprocess_alist));
}

Jim Blandy's avatar
Jim Blandy committed
720 721 722 723
/* This is how commands for the user decode process arguments.  It
   accepts a process, a process name, a buffer, a buffer name, or nil.
   Buffers denote the first process in the buffer, and nil denotes the
   current buffer.  */
Jim Blandy's avatar
Jim Blandy committed
724

725
static Lisp_Object
726
get_process (register Lisp_Object name)
Jim Blandy's avatar
Jim Blandy committed
727
{
728 729 730 731 732 733 734
  register Lisp_Object proc, obj;
  if (STRINGP (name))
    {
      obj = Fget_process (name);
      if (NILP (obj))
	obj = Fget_buffer (name);
      if (NILP (obj))
735
	error ("Process %s does not exist", SDATA (name));
736 737 738
    }
  else if (NILP (name))
    obj = Fcurrent_buffer ();
Jim Blandy's avatar
Jim Blandy committed
739
  else
740 741 742 743 744
    obj = name;

  /* Now obj should be either a buffer object or a process object.
   */
  if (BUFFERP (obj))
Jim Blandy's avatar
Jim Blandy committed
745
    {
746
      proc = Fget_buffer_process (obj);
Jim Blandy's avatar
Jim Blandy committed
747
      if (NILP (proc))
748
	error ("Buffer %s has no process", SDATA (XBUFFER (obj)->name));
Jim Blandy's avatar
Jim Blandy committed
749 750
    }
  else
751
    {
752
      CHECK_PROCESS (obj);
753 754 755
      proc = obj;
    }
  return proc;
Jim Blandy's avatar
Jim Blandy committed
756 757
}

758 759 760 761 762 763 764 765 766 767

#ifdef SIGCHLD
/* Fdelete_process promises to immediately forget about the process, but in
   reality, Emacs needs to remember those processes until they have been
   treated by sigchld_handler; otherwise this handler would consider the
   process as being synchronous and say that the synchronous process is
   dead.  */
static Lisp_Object deleted_pid_list;
#endif

Jim Blandy's avatar
Jim Blandy committed
768
DEFUN ("delete-process", Fdelete_process, Sdelete_process, 1, 1, 0,
769 770 771
       doc: /* Delete PROCESS: kill it and forget about it immediately.
PROCESS may be a process, a buffer, the name of a process or buffer, or
nil, indicating the current buffer's process.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
772
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
773
{
774 775
  register struct Lisp_Process *p;

776
  process = get_process (process);
777 778
  p = XPROCESS (process);

779
  p->raw_status_new = 0;
780
  if (NETCONN1_P (p) || SERIALCONN1_P (p))
Jim Blandy's avatar
Jim Blandy committed
781
    {
782
      p->status = Fcons (Qexit, Fcons (make_number (0), Qnil));
783
      p->tick = ++process_tick;
784
      status_notify (p);
785
      redisplay_preserve_echo_area (13);
Jim Blandy's avatar
Jim Blandy committed
786
    }
787
  else if (p->infd >= 0)
Jim Blandy's avatar
Jim Blandy committed
788
    {
789 790
#ifdef SIGCHLD
      Lisp_Object symbol;
791 792
      /* Assignment to EMACS_INT stops GCC whining about limited range
	 of data type.  */
793
      EMACS_INT pid = p->pid;
794 795

      /* No problem storing the pid here, as it is still in Vprocess_alist.  */
796
      deleted_pid_list = Fcons (make_fixnum_or_float (pid),
797 798 799 800 801 802 803 804 805
				/* GC treated elements set to nil.  */
				Fdelq (Qnil, deleted_pid_list));
      /* If the process has already signaled, remove it from the list.  */
      if (p->raw_status_new)
	update_status (p);
      symbol = p->status;
      if (CONSP (p->status))
	symbol = XCAR (p->status);
      if (EQ (symbol, Qsignal) || EQ (symbol, Qexit))
806 807
	deleted_pid_list
	  = Fdelete (make_fixnum_or_float (pid), deleted_pid_list);
808 809 810 811 812 813 814
      else
#endif
	{
	  Fkill_process (process, Qnil);
	  /* Do this now, since remove_process will make sigchld_handler do nothing.  */
	  p->status
	    = Fcons (Qsignal, Fcons (make_number (SIGKILL), Qnil));
815
	  p->tick = ++process_tick;
816
	  status_notify (p);
817
	  redisplay_preserve_echo_area (13);
818
	}
Jim Blandy's avatar
Jim Blandy committed
819
    }
820
  remove_process (process);
Jim Blandy's avatar
Jim Blandy committed
821 822 823 824
  return Qnil;
}

DEFUN ("process-status", Fprocess_status, Sprocess_status, 1, 1, 0,
825 826 827 828 829 830 831
       doc: /* Return the status of PROCESS.
The returned value is one of the following symbols:
run  -- for a process that is running.
stop -- for a process stopped but continuable.
exit -- for a process that has exited.
signal -- for a process that has got a fatal signal.
open -- for a network stream connection that is open.
832
listen -- for a network stream server that is listening.
833
closed -- for a network stream connection that is closed.
834 835
connect -- when waiting for a non-blocking connection to complete.
failed -- when a non-blocking connection has failed.
836 837 838
nil -- if arg is a process name and no such process exists.
PROCESS may be a process, a buffer, the name of a process, or
nil, indicating the current buffer's process.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
839
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
840 841 842
{
  register struct Lisp_Process *p;
  register Lisp_Object status;
843

844 845
  if (STRINGP (process))
    process = Fget_process (process);
846
  else
847
    process = get_process (process);
848

849 850
  if (NILP (process))
    return process;
851

852
  p = XPROCESS (process);
853
  if (p->raw_status_new)
Jim Blandy's avatar
Jim Blandy committed
854 855
    update_status (p);
  status = p->status;
856
  if (CONSP (status))
857
    status = XCAR (status);
858
  if (NETCONN1_P (p) || SERIALCONN1_P (p))
Jim Blandy's avatar
Jim Blandy committed
859
    {
860
      if (EQ (status, Qexit))
Jim Blandy's avatar
Jim Blandy committed
861
	status = Qclosed;
862 863 864 865
      else if (EQ (p->command, Qt))
	status = Qstop;
      else if (EQ (status, Qrun))
	status = Qopen;
Jim Blandy's avatar
Jim Blandy committed
866 867 868 869 870 871
    }
  return status;
}

DEFUN ("process-exit-status", Fprocess_exit_status, Sprocess_exit_status,
       1, 1, 0,
872 873
       doc: /* Return the exit status of PROCESS or the signal number that killed it.
If PROCESS has not yet exited or died, return 0.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
874
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
875
{
876
  CHECK_PROCESS (process);
877
  if (XPROCESS (process)->raw_status_new)
878 879
    update_status (XPROCESS (process));
  if (CONSP (XPROCESS (process)->status))
880
    return XCAR (XCDR (XPROCESS (process)->status));
Jim Blandy's avatar
Jim Blandy committed
881 882 883 884
  return make_number (0);
}

DEFUN ("process-id", Fprocess_id, Sprocess_id, 1, 1, 0,
885
       doc: /* Return the process id of PROCESS.
886
This is the pid of the external process which PROCESS uses or talks to.
887
For a network connection, this value is nil.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
888
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
889
{
890 891 892 893
  /* Assignment to EMACS_INT stops GCC whining about limited range of
     data type.  */
  EMACS_INT pid;

894
  CHECK_PROCESS (process);
895 896
  pid = XPROCESS (process)->pid;
  return (pid ? make_fixnum_or_float (pid) : Qnil);
Jim Blandy's avatar
Jim Blandy committed
897 898 899
}

DEFUN ("process-name", Fprocess_name, Sprocess_name, 1, 1, 0,
900 901 902
       doc: /* Return the name of PROCESS, as a string.
This is the name of the program invoked in PROCESS,
possibly modified to make it unique among process names.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
903
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
904
{
905
  CHECK_PROCESS (process);
906
  return XPROCESS (process)->name;
Jim Blandy's avatar
Jim Blandy committed
907 908 909
}

DEFUN ("process-command", Fprocess_command, Sprocess_command, 1, 1, 0,
910 911 912
       doc: /* Return the command that was executed to start PROCESS.
This is a list of strings, the first string being the program executed
and the rest of the strings being the arguments given to it.
913 914
For a network or serial process, this is nil (process is running) or t
\(process is stopped).  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
915
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
916
{
917
  CHECK_PROCESS (process);
918
  return XPROCESS (process)->command;
Jim Blandy's avatar
Jim Blandy committed
919 920
}

921
DEFUN ("process-tty-name", Fprocess_tty_name, Sprocess_tty_name, 1, 1, 0,
922 923 924
       doc: /* Return the name of the terminal PROCESS uses, or nil if none.
This is the terminal that the process itself reads and writes on,
not the name of the pty that Emacs uses to talk with that terminal.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
925
  (register Lisp_Object process)
926
{
927
  CHECK_PROCESS (process);
928
  return XPROCESS (process)->tty_name;
929 930
}

Jim Blandy's avatar
Jim Blandy committed
931
DEFUN ("set-process-buffer", Fset_process_buffer, Sset_process_buffer,
932 933
       2, 2, 0,
       doc: /* Set buffer associated with PROCESS to BUFFER (a buffer, or nil).  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
934
  (register Lisp_Object process, Lisp_Object buffer)
Jim Blandy's avatar
Jim Blandy committed
935
{
936 937
  struct Lisp_Process *p;

938
  CHECK_PROCESS (process);
Jim Blandy's avatar
Jim Blandy committed
939
  if (!NILP (buffer))
940
    CHECK_BUFFER (buffer);
941 942
  p = XPROCESS (process);
  p->buffer = buffer;
943
  if (NETCONN1_P (p) || SERIALCONN1_P (p))
944
    p->childp = Fplist_put (p->childp, QCbuffer, buffer);
945
  setup_process_coding_systems (process);
Jim Blandy's avatar
Jim Blandy committed
946 947 948 949
  return buffer;
}

DEFUN ("process-buffer", Fprocess_buffer, Sprocess_buffer,
950 951 952
       1, 1, 0,
       doc: /* Return the buffer PROCESS is associated with.
Output from PROCESS is inserted in this buffer unless PROCESS has a filter.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
953
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
954
{
955
  CHECK_PROCESS (process);
956
  return XPROCESS (process)->buffer;
Jim Blandy's avatar
Jim Blandy committed
957 958 959
}

DEFUN ("process-mark", Fprocess_mark, Sprocess_mark,
960 961
       1, 1, 0,
       doc: /* Return the marker for the end of the last output from PROCESS.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
962
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
963
{
964
  CHECK_PROCESS (process);
965
  return XPROCESS (process)->mark;
Jim Blandy's avatar
Jim Blandy committed
966 967 968
}

DEFUN ("set-process-filter", Fset_process_filter, Sset_process_filter,
969 970
       2, 2, 0,
       doc: /* Give PROCESS the filter function FILTER; nil means no filter.
971
A value of t means stop accepting output from the process.
972 973 974

When a process has a filter, its buffer is not used for output.
Instead, each time it does output, the entire string of output is
975
passed to the filter.
976

977
The filter gets two arguments: the process and the string of output.
978 979 980 981 982 983
The string argument is normally a multibyte string, except:
- if the process' input coding system is no-conversion or raw-text,
  it is a unibyte string (the non-converted input), or else
- if `default-enable-multibyte-characters' is nil, it is a unibyte
  string (the result of converting the decoded input multibyte
  string to unibyte with `string-make-unibyte').  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
984
  (register Lisp_Object process, Lisp_Object filter)
Jim Blandy's avatar
Jim Blandy committed
985
{
986
  struct Lisp_Process *p;
987

988
  CHECK_PROCESS (process);
989 990 991 992 993 994 995 996 997
  p = XPROCESS (process);

  /* Don't signal an error if the process' input file descriptor
     is closed.  This could make debugging Lisp more difficult,
     for example when doing something like

     (setq process (start-process ...))
     (debug)
     (set-process-filter process ...)  */
998

999
  if (p->infd >= 0)
1000
    {
1001
      if (EQ (filter, Qt) && !EQ (p->status, Qlisten))
1002
	{
1003 1004
	  FD_CLR (p->infd, &input_wait_mask);
	  FD_CLR (p->infd, &non_keyboard_wait_mask);
1005
	}
1006
      else if (EQ (p->filter, Qt)
1007 1008
	       /* Network or serial process not stopped:  */
	       && !EQ (p->command, Qt))
1009
	{
1010 1011
	  FD_SET (p->infd, &input_wait_mask);
	  FD_SET (p->infd, &non_keyboard_wait_mask);
1012
	}
1013
    }
1014

1015
  p->filter = filter;
1016
  if (NETCONN1_P (p) || SERIALCONN1_P (p))
1017
    p->childp = Fplist_put (p->childp, QCfilter, filter);
1018
  setup_process_coding_systems (process);
Jim Blandy's avatar
Jim Blandy committed
1019 1020 1021 1022
  return filter;
}

DEFUN ("process-filter", Fprocess_filter, Sprocess_filter,
1023 1024 1025
       1, 1, 0,
       doc: /* Returns the filter function of PROCESS; nil if none.
See `set-process-filter' for more info on filter functions.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
1026
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
1027
{
1028
  CHECK_PROCESS (process);
1029
  return XPROCESS (process)->filter;
Jim Blandy's avatar
Jim Blandy committed
1030 1031 1032
}

DEFUN ("set-process-sentinel", Fset_process_sentinel, Sset_process_sentinel,
1033 1034 1035 1036
       2, 2, 0,
       doc: /* Give PROCESS the sentinel SENTINEL; nil for none.
The sentinel is called as a function when the process changes state.
It gets two arguments: the process, and a string describing the change.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
1037
  (register Lisp_Object process, Lisp_Object sentinel)
Jim Blandy's avatar
Jim Blandy committed
1038
{
Kenichi Handa's avatar
Kenichi Handa committed
1039 1040
  struct Lisp_Process *p;

1041
  CHECK_PROCESS (process);
Kenichi Handa's avatar
Kenichi Handa committed
1042 1043 1044
  p = XPROCESS (process);

  p->sentinel = sentinel;
1045
  if (NETCONN1_P (p) || SERIALCONN1_P (p))
Kenichi Handa's avatar
Kenichi Handa committed
1046
    p->childp = Fplist_put (p->childp, QCsentinel, sentinel);
Jim Blandy's avatar
Jim Blandy committed
1047 1048 1049 1050
  return sentinel;
}

DEFUN ("process-sentinel", Fprocess_sentinel, Sprocess_sentinel,
1051 1052 1053
       1, 1, 0,
       doc: /* Return the sentinel of PROCESS; nil if none.
See `set-process-sentinel' for more info on sentinels.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
1054
  (register Lisp_Object process)
Jim Blandy's avatar
Jim Blandy committed
1055
{
1056
  CHECK_PROCESS (process);
1057
  return XPROCESS (process)->sentinel;
Jim Blandy's avatar
Jim Blandy committed
1058 1059
}

1060
DEFUN ("set-process-window-size", Fset_process_window_size,
1061 1062
       Sset_process_window_size, 3, 3, 0,
       doc: /* Tell PROCESS that it has logical window size HEIGHT and WIDTH.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
1063
  (register Lisp_Object process, Lisp_Object height, Lisp_Object width)
1064
{
1065 1066 1067
  CHECK_PROCESS (process);
  CHECK_NATNUM (height);
  CHECK_NATNUM (width);
1068

1069 1070
  if (XPROCESS (process)->infd < 0
      || set_window_size (XPROCESS (process)->infd,
1071
			  XINT (height), XINT (width)) <= 0)
1072 1073 1074 1075 1076
    return Qnil;
  else
    return Qt;
}

1077
DEFUN ("set-process-inherit-coding-system-flag",
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093
       Fset_process_inherit_coding_system_flag,
       Sset_process_inherit_coding_system_flag, 2, 2, 0,
       doc: /* Determine whether buffer of PROCESS will inherit coding-system.
If the second argument FLAG is non-nil, then the variable
`buffer-file-coding-system' of the buffer associated with PROCESS
will be bound to the value of the coding system used to decode
the process output.

This is useful when the coding system specified for the process buffer
leaves either the character code conversion or the end-of-line conversion
unspecified, or if the coding system used to decode the process output
is more appropriate for saving the process buffer.

Binding the variable `inherit-process-coding-system' to non-nil before
starting the process is an alternative way of setting the inherit flag
for the process which will run.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed