libiberty/pexecute.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.
   3    Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   4
   5 This file is part of the libiberty library.
   6 Libiberty is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 Libiberty is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with libiberty; see the file COPYING.LIB.  If not,
  18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* This file exports two functions: pexecute and pwait.  */
  22
  23 /* This file lives in at least two places: libiberty and gcc.
  24    Don't change one without the other.  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <stdio.h>
  31 #include <errno.h>
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35 #define ISSPACE (x) isspace(x)
  36 #ifdef HAVE_SYS_WAIT_H
  37 #include <sys/wait.h>
  38 #endif
  39
  40 #ifdef vfork /* Autoconf may define this to fork for us. */
  41 # define VFORK_STRING "fork"
  42 #else
  43 # define VFORK_STRING "vfork"
  44 #endif
  45 #ifdef HAVE_VFORK_H
  46 #include <vfork.h>
  47 #endif
  48 #ifdef VMS
  49 #define vfork() (decc$$alloc_vfork_blocks() >= 0 ? \
  50                lib$get_current_invo_context(decc$$get_vfork_jmpbuf()) : -1)
  51 #endif /* VMS */
  52
  53 #include "libiberty.h"
  54
  55 #if !defined (__CYGWIN__) && defined (__CYGWIN32__)
  56 #define __CYGWIN__ 1
  57 #endif
  58
  59 /* stdin file number.  */
  60 #define STDIN_FILE_NO 0
  61
  62 /* stdout file number.  */
  63 #define STDOUT_FILE_NO 1
  64
  65 /* value of `pipe': port index for reading.  */
  66 #define READ_PORT 0
  67
  68 /* value of `pipe': port index for writing.  */
  69 #define WRITE_PORT 1
  70
  71 static char *install_error_msg = "installation problem, cannot exec `%s'";
  72
  73 /* pexecute: execute a program.
  74
  75    PROGRAM and ARGV are the arguments to execv/execvp.
  76
  77    THIS_PNAME is name of the calling program (i.e. argv[0]).
  78
  79    TEMP_BASE is the path name, sans suffix, of a temporary file to use
  80    if needed.  This is currently only needed for MSDOS ports that don't use
  81    GO32 (do any still exist?).  Ports that don't need it can pass NULL.
  82
  83    (FLAGS & PEXECUTE_SEARCH) is non-zero if $PATH should be searched
  84    (??? It's not clear that GCC passes this flag correctly).
  85    (FLAGS & PEXECUTE_FIRST) is nonzero for the first process in chain.
  86    (FLAGS & PEXECUTE_FIRST) is nonzero for the last process in chain.
  87    FIRST_LAST could be simplified to only mark the last of a chain of processes
  88    but that requires the caller to always mark the last one (and not give up
  89    early if some error occurs).  It's more robust to require the caller to
  90    mark both ends of the chain.
  91
  92    The result is the pid on systems like Unix where we fork/exec and on systems
  93    like WIN32 and OS2 where we use spawn.  It is up to the caller to wait for
  94    the child.
  95
  96    The result is the WEXITSTATUS on systems like MSDOS where we spawn and wait
  97    for the child here.
  98
  99    Upon failure, ERRMSG_FMT and ERRMSG_ARG are set to the text of the error
 100    message with an optional argument (if not needed, ERRMSG_ARG is set to
 101    NULL), and -1 is returned.  `errno' is available to the caller to use.
 102
 103    pwait: cover function for wait.
 104
 105    PID is the process id of the task to wait for.
 106    STATUS is the `status' argument to wait.
 107    FLAGS is currently unused (allows future enhancement without breaking
 108    upward compatibility).  Pass 0 for now.
 109
 110    The result is the pid of the child reaped,
 111    or -1 for failure (errno says why).
 112
 113    On systems that don't support waiting for a particular child, PID is
 114    ignored.  On systems like MSDOS that don't really multitask pwait
 115    is just a mechanism to provide a consistent interface for the caller.
 116
 117    pfinish: finish generation of script
 118
 119    pfinish is necessary for systems like MPW where a script is generated that
 120    runs the requested programs.
 121 */
 122
 123 #ifdef __MSDOS__
 124
 125 /* MSDOS doesn't multitask, but for the sake of a consistent interface
 126    the code behaves like it does.  pexecute runs the program, tucks the
 127    exit code away, and returns a "pid".  pwait must be called to fetch the
 128    exit code.  */
 129
 130 #include <process.h>
 131
 132 /* For communicating information from pexecute to pwait.  */
 133 static int last_pid = 0;
 134 static int last_status = 0;
 135 static int last_reaped = 0;
 136
 137 int
 138 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 139      const char *program;
 140      char * const *argv;
 141      const char *this_pname;
 142      const char *temp_base;
 143      char **errmsg_fmt, **errmsg_arg;
 144      int flags;
 145 {
 146   int rc;
 147
 148   last_pid++;
 149   if (last_pid < 0)
 150     last_pid = 1;
 151
 152   if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
 153     abort ();
 154
 155 #ifdef __GO32__
 156   /* ??? What are the possible return values from spawnv?  */
 157   rc = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
 158 #else
 159   char *scmd, *rf;
 160   FILE *argfile;
 161   int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;
 162
 163   scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
 164   rf = scmd + strlen(program) + 2 + el;
 165   sprintf (scmd, "%s%s @%s.gp", program,
 166            (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
 167   argfile = fopen (rf, "w");
 168   if (argfile == 0)
 169     {
 170       int errno_save = errno;
 171       free (scmd);
 172       errno = errno_save;
 173       *errmsg_fmt = "cannot open `%s.gp'";
 174       *errmsg_arg = temp_base;
 175       return -1;
 176     }
 177
 178   for (i=1; argv[i]; i++)
 179     {
 180       char *cp;
 181       for (cp = argv[i]; *cp; cp++)
 182         {
 183           if (*cp == '"' || *cp == '\'' || *cp == '\\' || ISSPACE (*cp))
 184             fputc ('\\', argfile);
 185           fputc (*cp, argfile);
 186         }
 187       fputc ('\n', argfile);
 188     }
 189   fclose (argfile);
 190
 191   rc = system (scmd);
 192
 193   {
 194     int errno_save = errno;
 195     remove (rf);
 196     free (scmd);
 197     errno = errno_save;
 198   }
 199 #endif
 200
 201   if (rc == -1)
 202     {
 203       *errmsg_fmt = install_error_msg;
 204       *errmsg_arg = program;
 205       return -1;
 206     }
 207
 208   /* Tuck the status away for pwait, and return a "pid".  */
 209   last_status = rc << 8;
 210   return last_pid;
 211 }
 212
 213 int
 214 pwait (pid, status, flags)
 215      int pid;
 216      int *status;
 217      int flags;
 218 {
 219   /* On MSDOS each pexecute must be followed by it's associated pwait.  */
 220   if (pid != last_pid
 221       /* Called twice for the same child?  */
 222       || pid == last_reaped)
 223     {
 224       /* ??? ECHILD would be a better choice.  Can we use it here?  */
 225       errno = EINVAL;
 226       return -1;
 227     }
 228   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 229      Needed?  */
 230   *status = last_status;
 231   last_reaped = last_pid;
 232   return last_pid;
 233 }
 234
 235 #endif /* MSDOS */
 236
 237 #if defined (_WIN32) && ! defined (__UWIN__)
 238
 239 #include <process.h>
 240
 241 #ifdef __CYGWIN__
 242
 243 #define fix_argv(argvec) (argvec)
 244
 245 extern int _spawnv ();
 246 extern int _spawnvp ();
 247
 248 #else /* ! __CYGWIN__ */
 249
 250 /* This is a kludge to get around the Microsoft C spawn functions' propensity
 251    to remove the outermost set of double quotes from all arguments.  */
 252
 253 const char * const *
 254 fix_argv (argvec)
 255      char **argvec;
 256 {
 257   int i;
 258
 259   for (i = 1; argvec[i] != 0; i++)
 260     {
 261       int len, j;
 262       char *temp, *newtemp;
 263
 264       temp = argvec[i];
 265       len = strlen (temp);
 266       for (j = 0; j < len; j++)
 267         {
 268           if (temp[j] == '"')
 269             {
 270               newtemp = xmalloc (len + 2);
 271               strncpy (newtemp, temp, j);
 272               newtemp [j] = '\\';
 273               strncpy (&newtemp [j+1], &temp [j], len-j);
 274               newtemp [len+1] = 0;
 275               temp = newtemp;
 276               len++;
 277               j++;
 278             }
 279         }
 280
 281         argvec[i] = temp;
 282       }
 283
 284   return (const char * const *) argvec;
 285 }
 286 #endif /* __CYGWIN__ */
 287
 288 #include <io.h>
 289 #include <fcntl.h>
 290 #include <signal.h>
 291
 292 /* mingw32 headers may not define the following.  */
 293
 294 #ifndef _P_WAIT
 295 #  define _P_WAIT       0
 296 #  define _P_NOWAIT     1
 297 #  define _P_OVERLAY    2
 298 #  define _P_NOWAITO    3
 299 #  define _P_DETACH     4
 300
 301 #  define WAIT_CHILD    0
 302 #  define WAIT_GRANDCHILD       1
 303 #endif
 304
 305 /* Win32 supports pipes */
 306 int
 307 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 308      const char *program;
 309      char * const *argv;
 310      const char *this_pname;
 311      const char *temp_base;
 312      char **errmsg_fmt, **errmsg_arg;
 313      int flags;
 314 {
 315   int pid;
 316   int pdes[2], org_stdin, org_stdout;
 317   int input_desc, output_desc;
 318   int retries, sleep_interval;
 319
 320   /* Pipe waiting from last process, to be used as input for the next one.
 321      Value is STDIN_FILE_NO if no pipe is waiting
 322      (i.e. the next command is the first of a group).  */
 323   static int last_pipe_input;
 324
 325   /* If this is the first process, initialize.  */
 326   if (flags & PEXECUTE_FIRST)
 327     last_pipe_input = STDIN_FILE_NO;
 328
 329   input_desc = last_pipe_input;
 330
 331   /* If this isn't the last process, make a pipe for its output,
 332      and record it as waiting to be the input to the next process.  */
 333   if (! (flags & PEXECUTE_LAST))
 334     {
 335       if (_pipe (pdes, 256, O_BINARY) < 0)
 336         {
 337           *errmsg_fmt = "pipe";
 338           *errmsg_arg = NULL;
 339           return -1;
 340         }
 341       output_desc = pdes[WRITE_PORT];
 342       last_pipe_input = pdes[READ_PORT];
 343     }
 344   else
 345     {
 346       /* Last process.  */
 347       output_desc = STDOUT_FILE_NO;
 348       last_pipe_input = STDIN_FILE_NO;
 349     }
 350
 351   if (input_desc != STDIN_FILE_NO)
 352     {
 353       org_stdin = dup (STDIN_FILE_NO);
 354       dup2 (input_desc, STDIN_FILE_NO);
 355       close (input_desc);
 356     }
 357
 358   if (output_desc != STDOUT_FILE_NO)
 359     {
 360       org_stdout = dup (STDOUT_FILE_NO);
 361       dup2 (output_desc, STDOUT_FILE_NO);
 362       close (output_desc);
 363     }
 364
 365   pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
 366     (_P_NOWAIT, program, fix_argv(argv));
 367
 368   if (input_desc != STDIN_FILE_NO)
 369     {
 370       dup2 (org_stdin, STDIN_FILE_NO);
 371       close (org_stdin);
 372     }
 373
 374   if (output_desc != STDOUT_FILE_NO)
 375     {
 376       dup2 (org_stdout, STDOUT_FILE_NO);
 377       close (org_stdout);
 378     }
 379
 380   if (pid == -1)
 381     {
 382       *errmsg_fmt = install_error_msg;
 383       *errmsg_arg = program;
 384       return -1;
 385     }
 386
 387   return pid;
 388 }
 389
 390 /* MS CRTDLL doesn't return enough information in status to decide if the
 391    child exited due to a signal or not, rather it simply returns an
 392    integer with the exit code of the child; eg., if the child exited with
 393    an abort() call and didn't have a handler for SIGABRT, it simply returns
 394    with status = 3. We fix the status code to conform to the usual WIF*
 395    macros. Note that WIFSIGNALED will never be true under CRTDLL. */
 396
 397 int
 398 pwait (pid, status, flags)
 399      int pid;
 400      int *status;
 401      int flags;
 402 {
 403 #ifdef __CYGWIN__
 404   return wait (status);
 405 #else
 406   int termstat;
 407
 408   pid = _cwait (&termstat, pid, WAIT_CHILD);
 409
 410   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 411      Needed?  */
 412
 413   /* cwait returns the child process exit code in termstat.
 414      A value of 3 indicates that the child caught a signal, but not
 415      which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
 416      report SIGABRT.  */
 417   if (termstat == 3)
 418     *status = SIGABRT;
 419   else
 420     *status = (((termstat) & 0xff) << 8);
 421
 422   return pid;
 423 #endif /* __CYGWIN__ */
 424 }
 425
 426 #endif /* _WIN32 && ! __UWIN__ */
 427
 428 #ifdef OS2
 429
 430 /* ??? Does OS2 have process.h?  */
 431 extern int spawnv ();
 432 extern int spawnvp ();
 433
 434 int
 435 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 436      const char *program;
 437      char * const *argv;
 438      const char *this_pname;
 439      const char *temp_base;
 440      char **errmsg_fmt, **errmsg_arg;
 441      int flags;
 442 {
 443   int pid;
 444
 445   if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
 446     abort ();
 447   /* ??? Presumably 1 == _P_NOWAIT.  */
 448   pid = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
 449   if (pid == -1)
 450     {
 451       *errmsg_fmt = install_error_msg;
 452       *errmsg_arg = program;
 453       return -1;
 454     }
 455   return pid;
 456 }
 457
 458 int
 459 pwait (pid, status, flags)
 460      int pid;
 461      int *status;
 462      int flags;
 463 {
 464   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 465      Needed?  */
 466   int pid = wait (status);
 467   return pid;
 468 }
 469
 470 #endif /* OS2 */
 471
 472 #ifdef MPW
 473
 474 /* MPW pexecute doesn't actually run anything; instead, it writes out
 475    script commands that, when run, will do the actual executing.
 476
 477    For example, in GCC's case, GCC will write out several script commands:
 478
 479    cpp ...
 480    cc1 ...
 481    as ...
 482    ld ...
 483
 484    and then exit.  None of the above programs will have run yet.  The task
 485    that called GCC will then execute the script and cause cpp,etc. to run.
 486    The caller must invoke pfinish before calling exit.  This adds
 487    the finishing touches to the generated script.  */
 488
 489 static int first_time = 1;
 490
 491 int
 492 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 493      const char *program;
 494      char * const *argv;
 495      const char *this_pname;
 496      const char *temp_base;
 497      char **errmsg_fmt, **errmsg_arg;
 498      int flags;
 499 {
 500   char tmpprogram[255];
 501   char *cp, *tmpname;
 502   int i;
 503
 504   mpwify_filename (program, tmpprogram);
 505   if (first_time)
 506     {
 507       printf ("Set Failed 0\n");
 508       first_time = 0;
 509     }
 510
 511   fputs ("If {Failed} == 0\n", stdout);
 512   /* If being verbose, output a copy of the command.  It should be
 513      accurate enough and escaped enough to be "clickable".  */
 514   if (flags & PEXECUTE_VERBOSE)
 515     {
 516       fputs ("\tEcho ", stdout);
 517       fputc ('\'', stdout);
 518       fputs (tmpprogram, stdout);
 519       fputc ('\'', stdout);
 520       fputc (' ', stdout);
 521       for (i=1; argv[i]; i++)
 522         {
 523           fputc ('\'', stdout);
 524           /* See if we have an argument that needs fixing.  */
 525           if (strchr(argv[i], '/'))
 526             {
 527               tmpname = (char *) xmalloc (256);
 528               mpwify_filename (argv[i], tmpname);
 529               argv[i] = tmpname;
 530             }
 531           for (cp = argv[i]; *cp; cp++)
 532             {
 533               /* Write an Option-d escape char in front of special chars.  */
 534               if (strchr("'+", *cp))
 535                 fputc ('\266', stdout);
 536               fputc (*cp, stdout);
 537             }
 538           fputc ('\'', stdout);
 539           fputc (' ', stdout);
 540         }
 541       fputs ("\n", stdout);
 542     }
 543   fputs ("\t", stdout);
 544   fputs (tmpprogram, stdout);
 545   fputc (' ', stdout);
 546
 547   for (i=1; argv[i]; i++)
 548     {
 549       /* See if we have an argument that needs fixing.  */
 550       if (strchr(argv[i], '/'))
 551         {
 552           tmpname = (char *) xmalloc (256);
 553           mpwify_filename (argv[i], tmpname);
 554           argv[i] = tmpname;
 555         }
 556       if (strchr (argv[i], ' '))
 557         fputc ('\'', stdout);
 558       for (cp = argv[i]; *cp; cp++)
 559         {
 560           /* Write an Option-d escape char in front of special chars.  */
 561           if (strchr("'+", *cp))
 562             fputc ('\266', stdout);
 563           fputc (*cp, stdout);
 564         }
 565       if (strchr (argv[i], ' '))
 566         fputc ('\'', stdout);
 567       fputc (' ', stdout);
 568     }
 569
 570   fputs ("\n", stdout);
 571
 572   /* Output commands that arrange to clean up and exit if a failure occurs.
 573      We have to be careful to collect the status from the program that was
 574      run, rather than some other script command.  Also, we don't exit
 575      immediately, since necessary cleanups are at the end of the script.  */
 576   fputs ("\tSet TmpStatus {Status}\n", stdout);
 577   fputs ("\tIf {TmpStatus} != 0\n", stdout);
 578   fputs ("\t\tSet Failed {TmpStatus}\n", stdout);
 579   fputs ("\tEnd\n", stdout);
 580   fputs ("End\n", stdout);
 581
 582   /* We're just composing a script, can't fail here.  */
 583   return 0;
 584 }
 585
 586 int
 587 pwait (pid, status, flags)
 588      int pid;
 589      int *status;
 590      int flags;
 591 {
 592   *status = 0;
 593   return 0;
 594 }
 595
 596 /* Write out commands that will exit with the correct error code
 597    if something in the script failed.  */
 598
 599 void
 600 pfinish ()
 601 {
 602   printf ("\tExit \"{Failed}\"\n");
 603 }
 604
 605 #endif /* MPW */
 606
 607 /* include for Unix-like environments but not for Dos-like environments */
 608 #if ! defined (__MSDOS__) && ! defined (OS2) && ! defined (MPW) \
 609     && ! (defined (_WIN32) && ! defined (__UWIN__))
 610
 611 extern int execv ();
 612 extern int execvp ();
 613
 614 int
 615 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 616      const char *program;
 617      char * const *argv;
 618      const char *this_pname;
 619      const char *temp_base ATTRIBUTE_UNUSED;
 620      char **errmsg_fmt, **errmsg_arg;
 621      int flags;
 622 {
 623   int (*func)() = (flags & PEXECUTE_SEARCH ? execvp : execv);
 624   int pid;
 625   int pdes[2];
 626   int input_desc, output_desc;
 627   int retries, sleep_interval;
 628   /* Pipe waiting from last process, to be used as input for the next one.
 629      Value is STDIN_FILE_NO if no pipe is waiting
 630      (i.e. the next command is the first of a group).  */
 631   static int last_pipe_input;
 632
 633   /* If this is the first process, initialize.  */
 634   if (flags & PEXECUTE_FIRST)
 635     last_pipe_input = STDIN_FILE_NO;
 636
 637   input_desc = last_pipe_input;
 638
 639   /* If this isn't the last process, make a pipe for its output,
 640      and record it as waiting to be the input to the next process.  */
 641   if (! (flags & PEXECUTE_LAST))
 642     {
 643       if (pipe (pdes) < 0)
 644         {
 645           *errmsg_fmt = "pipe";
 646           *errmsg_arg = NULL;
 647           return -1;
 648         }
 649       output_desc = pdes[WRITE_PORT];
 650       last_pipe_input = pdes[READ_PORT];
 651     }
 652   else
 653     {
 654       /* Last process.  */
 655       output_desc = STDOUT_FILE_NO;
 656       last_pipe_input = STDIN_FILE_NO;
 657     }
 658
 659   /* Fork a subprocess; wait and retry if it fails.  */
 660   sleep_interval = 1;
 661   for (retries = 0; retries < 4; retries++)
 662     {
 663       pid = vfork ();
 664       if (pid >= 0)
 665         break;
 666       sleep (sleep_interval);
 667       sleep_interval *= 2;
 668     }
 669
 670   switch (pid)
 671     {
 672     case -1:
 673       {
 674         *errmsg_fmt = VFORK_STRING;
 675         *errmsg_arg = NULL;
 676         return -1;
 677       }
 678
 679     case 0: /* child */
 680       /* Move the input and output pipes into place, if necessary.  */
 681       if (input_desc != STDIN_FILE_NO)
 682         {
 683           close (STDIN_FILE_NO);
 684           dup (input_desc);
 685           close (input_desc);
 686         }
 687       if (output_desc != STDOUT_FILE_NO)
 688         {
 689           close (STDOUT_FILE_NO);
 690           dup (output_desc);
 691           close (output_desc);
 692         }
 693
 694       /* Close the parent's descs that aren't wanted here.  */
 695       if (last_pipe_input != STDIN_FILE_NO)
 696         close (last_pipe_input);
 697
 698       /* Exec the program.  */
 699       (*func) (program, argv);
 700
 701       /* Note: Calling fprintf and exit here doesn't seem right for vfork.  */
 702       fprintf (stderr, "%s: ", this_pname);
 703       fprintf (stderr, install_error_msg, program);
 704       fprintf (stderr, ": %s\n", xstrerror (errno));
 705       exit (-1);
 706       /* NOTREACHED */
 707       return 0;
 708
 709     default:
 710       /* In the parent, after forking.
 711          Close the descriptors that we made for this child.  */
 712       if (input_desc != STDIN_FILE_NO)
 713         close (input_desc);
 714       if (output_desc != STDOUT_FILE_NO)
 715         close (output_desc);
 716
 717       /* Return child's process number.  */
 718       return pid;
 719     }
 720 }
 721
 722 int
 723 pwait (pid, status, flags)
 724      int pid;
 725      int *status;
 726      int flags ATTRIBUTE_UNUSED;
 727 {
 728   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 729      Needed?  */
 730 #ifdef VMS
 731   pid = waitpid (-1, status, 0);
 732 #else
 733   pid = wait (status);
 734 #endif
 735   return pid;
 736 }
 737
 738 #endif /* ! __MSDOS__ && ! OS2 && ! MPW && ! (_WIN32 && ! __UWIN__) */