nojobs.c

   1 /* nojobs.c - functions that make children, remember them, and handle their termination. */
   2
   3 /* This file works under BSD, System V, minix, and Posix systems.  It does
   4    not implement job control. */
   5
   6 /* Copyright (C) 1987-2020 Free Software Foundation, Inc.
   7
   8    This file is part of GNU Bash, the Bourne Again SHell.
   9
  10    Bash is free software: you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation, either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    Bash is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "config.h"
  25
  26 #include "bashtypes.h"
  27 #include "filecntl.h"
  28
  29 #if defined (HAVE_UNISTD_H)
  30 #  include <unistd.h>
  31 #endif
  32
  33 #include <stdio.h>
  34 #include <signal.h>
  35 #include <errno.h>
  36
  37 #if defined (BUFFERED_INPUT)
  38 #  include "input.h"
  39 #endif
  40
  41 /* Need to include this up here for *_TTY_DRIVER definitions. */
  42 #include "shtty.h"
  43
  44 #include "bashintl.h"
  45
  46 #include "shell.h"
  47 #include "jobs.h"
  48 #include "execute_cmd.h"
  49 #include "trap.h"
  50
  51 #include "builtins/builtext.h"  /* for wait_builtin */
  52 #include "builtins/common.h"
  53
  54 #define DEFAULT_CHILD_MAX 4096
  55
  56 #if defined (_POSIX_VERSION) || !defined (HAVE_KILLPG)
  57 #  define killpg(pg, sig)               kill(-(pg),(sig))
  58 #endif /* USG || _POSIX_VERSION */
  59
  60 #if !defined (HAVE_SIGINTERRUPT) && !defined (HAVE_POSIX_SIGNALS)
  61 #  define siginterrupt(sig, code)
  62 #endif /* !HAVE_SIGINTERRUPT && !HAVE_POSIX_SIGNALS */
  63
  64 #if defined (HAVE_WAITPID)
  65 #  define WAITPID(pid, statusp, options) waitpid (pid, statusp, options)
  66 #else
  67 #  define WAITPID(pid, statusp, options) wait (statusp)
  68 #endif /* !HAVE_WAITPID */
  69
  70 /* Return the fd from which we are actually getting input. */
  71 #define input_tty() (shell_tty != -1) ? shell_tty : fileno (stderr)
  72
  73 #if !defined (errno)
  74 extern int errno;
  75 #endif /* !errno */
  76
  77 extern void set_original_signal PARAMS((int, SigHandler *));
  78
  79 volatile pid_t last_made_pid = NO_PID;
  80 volatile pid_t last_asynchronous_pid = NO_PID;
  81
  82 static int queue_sigchld;               /* dummy declaration */
  83 int waiting_for_child;
  84
  85 /* Call this when you start making children. */
  86 int already_making_children = 0;
  87
  88 /* The controlling tty for this shell. */
  89 int shell_tty = -1;
  90
  91 /* If this is non-zero, $LINES and $COLUMNS are reset after every process
  92    exits from get_tty_state(). */
  93 int check_window_size = CHECKWINSIZE_DEFAULT;
  94
  95 /* We don't have job control. */
  96 int job_control = 0;
  97
  98 int running_in_background = 0;  /* can't tell without job control */
  99
 100 /* STATUS and FLAGS are only valid if pid != NO_PID
 101    STATUS is only valid if (flags & PROC_RUNNING) == 0 */
 102 struct proc_status {
 103   pid_t pid;
 104   int status;   /* Exit status of PID or 128 + fatal signal number */
 105   int flags;
 106 };
 107
 108 /* Values for proc_status.flags */
 109 #define PROC_RUNNING    0x01
 110 #define PROC_NOTIFIED   0x02
 111 #define PROC_ASYNC      0x04
 112 #define PROC_SIGNALED   0x10
 113
 114 /* Return values from find_status_by_pid */
 115 #define PROC_BAD         -1
 116 #define PROC_STILL_ALIVE -2
 117
 118 static struct proc_status *pid_list = (struct proc_status *)NULL;
 119 static int pid_list_size;
 120 static int wait_sigint_received;
 121
 122 static long child_max = -1L;
 123
 124 static void alloc_pid_list PARAMS((void));
 125 static int find_proc_slot PARAMS((pid_t));
 126 static int find_index_by_pid PARAMS((pid_t));
 127 static int find_status_by_pid PARAMS((pid_t));
 128 static int process_exit_status PARAMS((WAIT));
 129 static int find_termsig_by_pid PARAMS((pid_t));
 130 static int get_termsig PARAMS((WAIT));
 131 static void set_pid_status PARAMS((pid_t, WAIT));
 132 static void set_pid_flags PARAMS((pid_t, int));
 133 static void unset_pid_flags PARAMS((pid_t, int));
 134 static int get_pid_flags PARAMS((pid_t));
 135 static void add_pid PARAMS((pid_t, int));
 136 static void mark_dead_jobs_as_notified PARAMS((int));
 137
 138 static sighandler wait_sigint_handler PARAMS((int));
 139 static char *j_strsignal PARAMS((int));
 140
 141 #if defined (HAVE_WAITPID)
 142 static void reap_zombie_children PARAMS((void));
 143 #endif
 144
 145 #if !defined (HAVE_SIGINTERRUPT) && defined (HAVE_POSIX_SIGNALS)
 146 static int siginterrupt PARAMS((int, int));
 147 #endif
 148
 149 static void restore_sigint_handler PARAMS((void));
 150
 151 /* Allocate new, or grow existing PID_LIST. */
 152 static void
 153 alloc_pid_list ()
 154 {
 155   register int i;
 156   int old = pid_list_size;
 157
 158   pid_list_size += 10;
 159   pid_list = (struct proc_status *)xrealloc (pid_list, pid_list_size * sizeof (struct proc_status));
 160
 161   /* None of the newly allocated slots have process id's yet. */
 162   for (i = old; i < pid_list_size; i++)
 163     {
 164       pid_list[i].pid = NO_PID;
 165       pid_list[i].status = pid_list[i].flags = 0;
 166     }
 167 }
 168
 169 /* Return the offset within the PID_LIST array of an empty slot.  This can
 170    create new slots if all of the existing slots are taken. */
 171 static int
 172 find_proc_slot (pid)
 173      pid_t pid;
 174 {
 175   register int i;
 176
 177   for (i = 0; i < pid_list_size; i++)
 178     if (pid_list[i].pid == NO_PID || pid_list[i].pid == pid)
 179       return (i);
 180
 181   if (i == pid_list_size)
 182     alloc_pid_list ();
 183
 184   return (i);
 185 }
 186
 187 /* Return the offset within the PID_LIST array of a slot containing PID,
 188    or the value NO_PID if the pid wasn't found. */
 189 static int
 190 find_index_by_pid (pid)
 191      pid_t pid;
 192 {
 193   register int i;
 194
 195   for (i = 0; i < pid_list_size; i++)
 196     if (pid_list[i].pid == pid)
 197       return (i);
 198
 199   return (NO_PID);
 200 }
 201
 202 /* Return the status of PID as looked up in the PID_LIST array.  A
 203    return value of PROC_BAD indicates that PID wasn't found. */
 204 static int
 205 find_status_by_pid (pid)
 206      pid_t pid;
 207 {
 208   int i;
 209
 210   i = find_index_by_pid (pid);
 211   if (i == NO_PID)
 212     return (PROC_BAD);
 213   if (pid_list[i].flags & PROC_RUNNING)
 214     return (PROC_STILL_ALIVE);
 215   return (pid_list[i].status);
 216 }
 217
 218 static int
 219 process_exit_status (status)
 220      WAIT status;
 221 {
 222   if (WIFSIGNALED (status))
 223     return (128 + WTERMSIG (status));
 224   else
 225     return (WEXITSTATUS (status));
 226 }
 227
 228 /* Return the status of PID as looked up in the PID_LIST array.  A
 229    return value of PROC_BAD indicates that PID wasn't found. */
 230 static int
 231 find_termsig_by_pid (pid)
 232      pid_t pid;
 233 {
 234   int i;
 235
 236   i = find_index_by_pid (pid);
 237   if (i == NO_PID)
 238     return (0);
 239   if (pid_list[i].flags & PROC_RUNNING)
 240     return (0);
 241   return (get_termsig ((WAIT)pid_list[i].status));
 242 }
 243
 244 /* Set LAST_COMMAND_EXIT_SIGNAL depending on STATUS.  If STATUS is -1, look
 245    up PID in the pid array and set LAST_COMMAND_EXIT_SIGNAL appropriately
 246    depending on its flags and exit status. */
 247 static int
 248 get_termsig (status)
 249      WAIT status;
 250 {
 251   if (WIFSTOPPED (status) == 0 && WIFSIGNALED (status))
 252     return (WTERMSIG (status));
 253   else
 254     return (0);
 255 }
 256
 257 /* Give PID the status value STATUS in the PID_LIST array. */
 258 static void
 259 set_pid_status (pid, status)
 260      pid_t pid;
 261      WAIT status;
 262 {
 263   int slot;
 264
 265 #if defined (COPROCESS_SUPPORT)
 266   coproc_pidchk (pid, status);
 267 #endif
 268
 269 #if defined (PROCESS_SUBSTITUTION)
 270   if ((slot = find_procsub_child (pid)) >= 0)
 271     set_procsub_status (slot, pid, WSTATUS (status));
 272     /* XXX - also saving in list below */
 273 #endif
 274
 275   slot = find_index_by_pid (pid);
 276   if (slot == NO_PID)
 277     return;
 278
 279   pid_list[slot].status = process_exit_status (status);
 280   pid_list[slot].flags &= ~PROC_RUNNING;
 281   if (WIFSIGNALED (status))
 282     pid_list[slot].flags |= PROC_SIGNALED;
 283   /* If it's not a background process, mark it as notified so it gets
 284      cleaned up. */
 285   if ((pid_list[slot].flags & PROC_ASYNC) == 0)
 286     pid_list[slot].flags |= PROC_NOTIFIED;
 287 }
 288
 289 /* Give PID the flags FLAGS in the PID_LIST array. */
 290 static void
 291 set_pid_flags (pid, flags)
 292      pid_t pid;
 293      int flags;
 294 {
 295   int slot;
 296
 297   slot = find_index_by_pid (pid);
 298   if (slot == NO_PID)
 299     return;
 300
 301   pid_list[slot].flags |= flags;
 302 }
 303
 304 /* Unset FLAGS for PID in the pid list */
 305 static void
 306 unset_pid_flags (pid, flags)
 307      pid_t pid;
 308      int flags;
 309 {
 310   int slot;
 311
 312   slot = find_index_by_pid (pid);
 313   if (slot == NO_PID)
 314     return;
 315
 316   pid_list[slot].flags &= ~flags;
 317 }
 318
 319 /* Return the flags corresponding to PID in the PID_LIST array. */
 320 static int
 321 get_pid_flags (pid)
 322      pid_t pid;
 323 {
 324   int slot;
 325
 326   slot = find_index_by_pid (pid);
 327   if (slot == NO_PID)
 328     return 0;
 329
 330   return (pid_list[slot].flags);
 331 }
 332
 333 static void
 334 add_pid (pid, async)
 335      pid_t pid;
 336      int async;
 337 {
 338   int slot;
 339
 340   slot = find_proc_slot (pid);
 341
 342   pid_list[slot].pid = pid;
 343   pid_list[slot].status = -1;
 344   pid_list[slot].flags = PROC_RUNNING;
 345   if (async)
 346     pid_list[slot].flags |= PROC_ASYNC;
 347 }
 348
 349 static void
 350 mark_dead_jobs_as_notified (force)
 351      int force;
 352 {
 353   register int i, ndead;
 354
 355   /* first, count the number of non-running async jobs if FORCE == 0 */
 356   for (i = ndead = 0; force == 0 && i < pid_list_size; i++)
 357     {
 358       if (pid_list[i].pid == NO_PID)
 359         continue;
 360       if (((pid_list[i].flags & PROC_RUNNING) == 0) &&
 361            (pid_list[i].flags & PROC_ASYNC))
 362         ndead++;
 363     }
 364
 365   if (child_max < 0)
 366     child_max = getmaxchild ();
 367   if (child_max < 0)
 368     child_max = DEFAULT_CHILD_MAX;
 369
 370   if (force == 0 && ndead <= child_max)
 371     return;
 372
 373   /* If FORCE == 0, we just mark as many non-running async jobs as notified
 374      to bring us under the CHILD_MAX limit. */
 375   for (i = 0; i < pid_list_size; i++)
 376     {
 377       if (pid_list[i].pid == NO_PID)
 378         continue;
 379       if (((pid_list[i].flags & PROC_RUNNING) == 0) &&
 380            pid_list[i].pid != last_asynchronous_pid)
 381         {
 382           pid_list[i].flags |= PROC_NOTIFIED;
 383           if (force == 0 && (pid_list[i].flags & PROC_ASYNC) && --ndead <= child_max)
 384             break;
 385         }
 386     }
 387 }
 388
 389 /* Remove all dead, notified jobs from the pid_list. */
 390 int
 391 cleanup_dead_jobs ()
 392 {
 393   register int i;
 394
 395 #if defined (HAVE_WAITPID)
 396   reap_zombie_children ();
 397 #endif
 398
 399   for (i = 0; i < pid_list_size; i++)
 400     {
 401       if (pid_list[i].pid != NO_PID &&
 402             (pid_list[i].flags & PROC_RUNNING) == 0 &&
 403             (pid_list[i].flags & PROC_NOTIFIED))
 404         pid_list[i].pid = NO_PID;
 405     }
 406
 407 #if defined (COPROCESS_SUPPORT)
 408   coproc_reap ();
 409 #endif
 410
 411   return 0;
 412 }
 413
 414 void
 415 reap_dead_jobs ()
 416 {
 417   mark_dead_jobs_as_notified (0);
 418   cleanup_dead_jobs ();
 419 }
 420
 421 /* Initialize the job control mechanism, and set up the tty stuff. */
 422 int
 423 initialize_job_control (force)
 424      int force;
 425 {
 426   shell_tty = fileno (stderr);
 427
 428   if (interactive)
 429     get_tty_state ();
 430   return 0;
 431 }
 432
 433 /* Setup this shell to handle C-C, etc. */
 434 void
 435 initialize_job_signals ()
 436 {
 437   set_signal_handler (SIGINT, sigint_sighandler);
 438
 439   /* If this is a login shell we don't wish to be disturbed by
 440      stop signals. */
 441   if (login_shell)
 442     ignore_tty_job_signals ();
 443 }
 444
 445 #if defined (HAVE_WAITPID)
 446 /* Collect the status of all zombie children so that their system
 447    resources can be deallocated. */
 448 static void
 449 reap_zombie_children ()
 450 {
 451 #  if defined (WNOHANG)
 452   pid_t pid;
 453   WAIT status;
 454
 455   CHECK_TERMSIG;
 456   CHECK_WAIT_INTR;
 457   while ((pid = waitpid (-1, (int *)&status, WNOHANG)) > 0)
 458     set_pid_status (pid, status);
 459 #  endif /* WNOHANG */
 460   CHECK_TERMSIG;
 461   CHECK_WAIT_INTR;
 462 }
 463 #endif /* WAITPID */
 464
 465 #if !defined (HAVE_SIGINTERRUPT) && defined (HAVE_POSIX_SIGNALS)
 466
 467 #if !defined (SA_RESTART)
 468 #  define SA_RESTART 0
 469 #endif
 470
 471 static int
 472 siginterrupt (sig, flag)
 473      int sig, flag;
 474 {
 475   struct sigaction act;
 476
 477   sigaction (sig, (struct sigaction *)NULL, &act);
 478
 479   if (flag)
 480     act.sa_flags &= ~SA_RESTART;
 481   else
 482     act.sa_flags |= SA_RESTART;
 483
 484   return (sigaction (sig, &act, (struct sigaction *)NULL));
 485 }
 486 #endif /* !HAVE_SIGINTERRUPT && HAVE_POSIX_SIGNALS */
 487
 488 /* Fork, handling errors.  Returns the pid of the newly made child, or 0.
 489    COMMAND is just for remembering the name of the command; we don't do
 490    anything else with it.  ASYNC_P says what to do with the tty.  If
 491    non-zero, then don't give it away. */
 492 pid_t
 493 make_child (command, flags)
 494      char *command;
 495      int flags;
 496 {
 497   pid_t pid;
 498   int async_p, forksleep;
 499   sigset_t set, oset;
 500
 501   /* Discard saved memory. */
 502   if (command)
 503     free (command);
 504
 505   async_p = (flags & FORK_ASYNC);
 506   start_pipeline ();
 507
 508 #if defined (BUFFERED_INPUT)
 509   /* If default_buffered_input is active, we are reading a script.  If
 510      the command is asynchronous, we have already duplicated /dev/null
 511      as fd 0, but have not changed the buffered stream corresponding to
 512      the old fd 0.  We don't want to sync the stream in this case. */
 513   if (default_buffered_input != -1 && (!async_p || default_buffered_input > 0))
 514     sync_buffered_stream (default_buffered_input);
 515 #endif /* BUFFERED_INPUT */
 516
 517   /* Block SIGTERM here and unblock in child after fork resets the
 518      set of pending signals */
 519   if (interactive_shell)
 520     {
 521       sigemptyset (&set);
 522       sigaddset (&set, SIGTERM);
 523       sigemptyset (&oset);
 524       sigprocmask (SIG_BLOCK, &set, &oset);
 525       set_signal_handler (SIGTERM, SIG_DFL);
 526     }
 527
 528   /* Create the child, handle severe errors.  Retry on EAGAIN. */
 529   forksleep = 1;
 530   while ((pid = fork ()) < 0 && errno == EAGAIN && forksleep < FORKSLEEP_MAX)
 531     {
 532       sys_error ("fork: retry");
 533
 534 #if defined (HAVE_WAITPID)
 535       /* Posix systems with a non-blocking waitpid () system call available
 536          get another chance after zombies are reaped. */
 537       reap_zombie_children ();
 538       if (forksleep > 1 && sleep (forksleep) != 0)
 539         break;
 540 #else
 541       if (sleep (forksleep) != 0)
 542         break;
 543 #endif /* HAVE_WAITPID */
 544       forksleep <<= 1;
 545     }
 546
 547   if (pid != 0)
 548     if (interactive_shell)
 549       {
 550         set_signal_handler (SIGTERM, SIG_IGN);
 551         sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
 552       }
 553
 554   if (pid < 0)
 555     {
 556       sys_error ("fork");
 557       last_command_exit_value = EX_NOEXEC;
 558       throw_to_top_level ();
 559     }
 560
 561   if (pid == 0)
 562     {
 563 #if defined (BUFFERED_INPUT)
 564       unset_bash_input (0);
 565 #endif /* BUFFERED_INPUT */
 566
 567       CLRINTERRUPT;     /* XXX - children have their own interrupt state */
 568
 569       /* Restore top-level signal mask. */
 570       restore_sigmask ();
 571
 572 #if 0
 573       /* Ignore INT and QUIT in asynchronous children. */
 574       if (async_p)
 575         last_asynchronous_pid = getpid ();
 576 #endif
 577
 578       subshell_environment |= SUBSHELL_IGNTRAP;
 579
 580       default_tty_job_signals ();
 581     }
 582   else
 583     {
 584       /* In the parent. */
 585
 586       last_made_pid = pid;
 587
 588       if (async_p)
 589         last_asynchronous_pid = pid;
 590
 591       add_pid (pid, async_p);
 592     }
 593   return (pid);
 594 }
 595
 596 void
 597 ignore_tty_job_signals ()
 598 {
 599 #if defined (SIGTSTP)
 600   set_signal_handler (SIGTSTP, SIG_IGN);
 601   set_signal_handler (SIGTTIN, SIG_IGN);
 602   set_signal_handler (SIGTTOU, SIG_IGN);
 603 #endif
 604 }
 605
 606 void
 607 default_tty_job_signals ()
 608 {
 609 #if defined (SIGTSTP)
 610   if (signal_is_trapped (SIGTSTP) == 0 && signal_is_hard_ignored (SIGTSTP))
 611     set_signal_handler (SIGTSTP, SIG_IGN);
 612   else
 613     set_signal_handler (SIGTSTP, SIG_DFL);
 614   if (signal_is_trapped (SIGTTIN) == 0 && signal_is_hard_ignored (SIGTTIN))
 615     set_signal_handler (SIGTTIN, SIG_IGN);
 616   else
 617     set_signal_handler (SIGTTIN, SIG_DFL);
 618   if (signal_is_trapped (SIGTTOU) == 0 && signal_is_hard_ignored (SIGTTOU))
 619     set_signal_handler (SIGTTOU, SIG_IGN);
 620   else
 621     set_signal_handler (SIGTTOU, SIG_DFL);
 622 #endif
 623 }
 624
 625 /* Called once in a parent process. */
 626 void
 627 get_original_tty_job_signals ()
 628 {
 629   static int fetched = 0;
 630
 631   if (fetched == 0)
 632     {
 633 #if defined (SIGTSTP)
 634       if (interactive_shell)
 635         {
 636           set_original_signal (SIGTSTP, SIG_DFL);
 637           set_original_signal (SIGTTIN, SIG_DFL);
 638           set_original_signal (SIGTTOU, SIG_DFL);
 639         }
 640       else
 641         {
 642           get_original_signal (SIGTSTP);
 643           get_original_signal (SIGTTIN);
 644           get_original_signal (SIGTTOU);
 645         }
 646 #endif
 647       fetched = 1;
 648     }
 649 }
 650
 651 /* Wait for a single pid (PID) and return its exit status.  Called by
 652    the wait builtin. */
 653 int
 654 wait_for_single_pid (pid, flags)
 655      pid_t pid;
 656      int flags;
 657 {
 658   pid_t got_pid;
 659   WAIT status;
 660   int pstatus;
 661
 662   pstatus = find_status_by_pid (pid);
 663
 664   if (pstatus == PROC_BAD)
 665     {
 666       internal_error (_("wait: pid %ld is not a child of this shell"), (long)pid);
 667       return (127);
 668     }
 669
 670   if (pstatus != PROC_STILL_ALIVE)
 671     {
 672       if (pstatus > 128)
 673         last_command_exit_signal = find_termsig_by_pid (pid);
 674       return (pstatus);
 675     }
 676
 677   siginterrupt (SIGINT, 1);
 678   while ((got_pid = WAITPID (pid, &status, 0)) != pid)
 679     {
 680       CHECK_TERMSIG;
 681       CHECK_WAIT_INTR;
 682       if (got_pid < 0)
 683         {
 684           if (errno != EINTR && errno != ECHILD)
 685             {
 686               siginterrupt (SIGINT, 0);
 687               sys_error ("wait");
 688             }
 689           break;
 690         }
 691       else if (got_pid > 0)
 692         set_pid_status (got_pid, status);
 693     }
 694
 695   if (got_pid > 0)
 696     {
 697       set_pid_status (got_pid, status);
 698       set_pid_flags (got_pid, PROC_NOTIFIED);
 699     }
 700
 701   siginterrupt (SIGINT, 0);
 702   QUIT;
 703   CHECK_WAIT_INTR;
 704
 705   return (got_pid > 0 ? process_exit_status (status) : -1);
 706 }
 707
 708 /* Wait for all of the shell's children to exit.  Called by the `wait'
 709    builtin. */
 710 void
 711 wait_for_background_pids (ps)
 712      struct procstat *ps;
 713 {
 714   pid_t got_pid;
 715   WAIT status;
 716
 717   /* If we aren't using job control, we let the kernel take care of the
 718      bookkeeping for us.  wait () will return -1 and set errno to ECHILD
 719      when there are no more unwaited-for child processes on both
 720      4.2 BSD-based and System V-based systems. */
 721
 722   siginterrupt (SIGINT, 1);
 723
 724   /* Wait for ECHILD */
 725   waiting_for_child = 1;
 726   while ((got_pid = WAITPID (-1, &status, 0)) != -1)
 727     {
 728       waiting_for_child = 0;
 729       set_pid_status (got_pid, status);
 730       if (ps)
 731         {
 732           ps->pid = got_pid;
 733           ps->status = process_exit_status (status);
 734         }
 735       waiting_for_child = 1;
 736       CHECK_WAIT_INTR;
 737     }
 738   waiting_for_child = 0;
 739
 740   if (errno != EINTR && errno != ECHILD)
 741     {
 742       siginterrupt (SIGINT, 0);
 743       sys_error("wait");
 744     }
 745
 746   siginterrupt (SIGINT, 0);
 747   QUIT;
 748   CHECK_WAIT_INTR;
 749
 750   mark_dead_jobs_as_notified (1);
 751   cleanup_dead_jobs ();
 752 }
 753
 754 void
 755 wait_sigint_cleanup ()
 756 {
 757 }
 758
 759 /* Make OLD_SIGINT_HANDLER the SIGINT signal handler. */
 760 #define INVALID_SIGNAL_HANDLER (SigHandler *)wait_for_background_pids
 761 static SigHandler *old_sigint_handler = INVALID_SIGNAL_HANDLER;
 762
 763 static void
 764 restore_sigint_handler ()
 765 {
 766   if (old_sigint_handler != INVALID_SIGNAL_HANDLER)
 767     {
 768       set_signal_handler (SIGINT, old_sigint_handler);
 769       old_sigint_handler = INVALID_SIGNAL_HANDLER;
 770     }
 771 }
 772
 773 /* Handle SIGINT while we are waiting for children in a script to exit.
 774    All interrupts are effectively ignored by the shell, but allowed to
 775    kill a running job. */
 776 static sighandler
 777 wait_sigint_handler (sig)
 778      int sig;
 779 {
 780   SigHandler *sigint_handler;
 781
 782   /* If we got a SIGINT while in `wait', and SIGINT is trapped, do
 783      what POSIX.2 says (see builtins/wait.def for more info). */
 784   if (this_shell_builtin && this_shell_builtin == wait_builtin &&
 785       signal_is_trapped (SIGINT) &&
 786       ((sigint_handler = trap_to_sighandler (SIGINT)) == trap_handler))
 787     {
 788       last_command_exit_value = 128+SIGINT;
 789       restore_sigint_handler ();
 790       trap_handler (SIGINT);    /* set pending_traps[SIGINT] */
 791       wait_signal_received = SIGINT;
 792       SIGRETURN (0);
 793     }
 794
 795   wait_sigint_received = 1;
 796
 797   SIGRETURN (0);
 798 }
 799
 800 static char *
 801 j_strsignal (s)
 802      int s;
 803 {
 804   static char retcode_name_buffer[64] = { '\0' };
 805   char *x;
 806
 807   x = strsignal (s);
 808   if (x == 0)
 809     {
 810       x = retcode_name_buffer;
 811       sprintf (x, "Signal %d", s);
 812     }
 813   return x;
 814 }
 815
 816 /* Wait for pid (one of our children) to terminate.  This is called only
 817    by the execution code in execute_cmd.c. */
 818 int
 819 wait_for (pid, flags)
 820      pid_t pid;
 821      int flags;
 822 {
 823   int return_val, pstatus;
 824   pid_t got_pid;
 825   WAIT status;
 826
 827   pstatus = find_status_by_pid (pid);
 828
 829   if (pstatus == PROC_BAD)
 830     return (0);
 831
 832   if (pstatus != PROC_STILL_ALIVE)
 833     {
 834       if (pstatus > 128)
 835         last_command_exit_signal = find_termsig_by_pid (pid);
 836       return (pstatus);
 837     }
 838
 839   /* If we are running a script, ignore SIGINT while we're waiting for
 840      a child to exit.  The loop below does some of this, but not all. */
 841   wait_sigint_received = 0;
 842   if (interactive_shell == 0)
 843     old_sigint_handler = set_signal_handler (SIGINT, wait_sigint_handler);
 844
 845   waiting_for_child = 1;
 846   CHECK_WAIT_INTR;
 847   while ((got_pid = WAITPID (-1, &status, 0)) != pid) /* XXX was pid now -1 */
 848     {
 849       waiting_for_child = 0;
 850       CHECK_TERMSIG;
 851       CHECK_WAIT_INTR;
 852       if (got_pid < 0 && errno == ECHILD)
 853         {
 854 #if !defined (_POSIX_VERSION)
 855           status.w_termsig = status.w_retcode = 0;
 856 #else
 857           status = 0;
 858 #endif /* _POSIX_VERSION */
 859           break;
 860         }
 861       else if (got_pid < 0 && errno != EINTR)
 862         programming_error ("wait_for(%ld): %s", (long)pid, strerror(errno));
 863       else if (got_pid > 0)
 864         set_pid_status (got_pid, status);
 865       waiting_for_child = 1;
 866     }
 867   waiting_for_child = 0;
 868
 869   if (got_pid > 0)
 870     set_pid_status (got_pid, status);
 871
 872 #if defined (HAVE_WAITPID)
 873   if (got_pid >= 0)
 874     reap_zombie_children ();
 875 #endif /* HAVE_WAITPID */
 876
 877   CHECK_TERMSIG;
 878   CHECK_WAIT_INTR;
 879
 880   if (interactive_shell == 0)
 881     {
 882       SigHandler *temp_handler;
 883
 884       temp_handler = old_sigint_handler;
 885       restore_sigint_handler ();
 886
 887       /* If the job exited because of SIGINT, make sure the shell acts as if
 888          it had received one also. */
 889       if (WIFSIGNALED (status) && (WTERMSIG (status) == SIGINT))
 890         {
 891
 892           if (maybe_call_trap_handler (SIGINT) == 0)
 893             {
 894               if (temp_handler == SIG_DFL)
 895                 termsig_handler (SIGINT);
 896               else if (temp_handler != INVALID_SIGNAL_HANDLER && temp_handler != SIG_IGN)
 897                 (*temp_handler) (SIGINT);
 898             }
 899         }
 900     }
 901
 902   /* Default return value. */
 903   /* ``a full 8 bits of status is returned'' */
 904   return_val = process_exit_status (status);
 905   last_command_exit_signal = get_termsig (status);
 906
 907 #if defined (DONT_REPORT_SIGPIPE) && defined (DONT_REPORT_SIGTERM)
 908 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGPIPE && (x) != SIGTERM)
 909 #elif !defined (DONT_REPORT_SIGPIPE) && !defined (DONT_REPORT_SIGTERM)
 910 #  define REPORTSIG(x) ((x) != SIGINT)
 911 #elif defined (DONT_REPORT_SIGPIPE)
 912 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGPIPE)
 913 #else
 914 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGTERM)
 915 #endif
 916
 917   if ((WIFSTOPPED (status) == 0) && WIFSIGNALED (status) && REPORTSIG(WTERMSIG (status)))
 918     {
 919       fprintf (stderr, "%s", j_strsignal (WTERMSIG (status)));
 920       if (WIFCORED (status))
 921         fprintf (stderr, _(" (core dumped)"));
 922       fprintf (stderr, "\n");
 923     }
 924
 925   if (interactive_shell && subshell_environment == 0)
 926     {
 927       if (WIFSIGNALED (status) || WIFSTOPPED (status))
 928         set_tty_state ();
 929       else
 930         get_tty_state ();
 931     }
 932   else if (interactive_shell == 0 && subshell_environment == 0 && check_window_size)
 933     get_new_window_size (0, (int *)0, (int *)0);
 934
 935   return (return_val);
 936 }
 937
 938 /* Send PID SIGNAL.  Returns -1 on failure, 0 on success.  If GROUP is non-zero,
 939    or PID is less than -1, then kill the process group associated with PID. */
 940 int
 941 kill_pid (pid, signal, group)
 942      pid_t pid;
 943      int signal, group;
 944 {
 945   int result;
 946
 947   if (pid < -1)
 948     {
 949       pid = -pid;
 950       group = 1;
 951     }
 952   result = group ? killpg (pid, signal) : kill (pid, signal);
 953   return (result);
 954 }
 955
 956 static TTYSTRUCT shell_tty_info;
 957 static int got_tty_state;
 958
 959 /* Fill the contents of shell_tty_info with the current tty info. */
 960 int
 961 get_tty_state ()
 962 {
 963   int tty;
 964
 965   tty = input_tty ();
 966   if (tty != -1)
 967     {
 968       ttgetattr (tty, &shell_tty_info);
 969       got_tty_state = 1;
 970       if (check_window_size)
 971         get_new_window_size (0, (int *)0, (int *)0);
 972     }
 973   return 0;
 974 }
 975
 976 /* Make the current tty use the state in shell_tty_info. */
 977 int
 978 set_tty_state ()
 979 {
 980   int tty;
 981
 982   tty = input_tty ();
 983   if (tty != -1)
 984     {
 985       if (got_tty_state == 0)
 986         return 0;
 987       ttsetattr (tty, &shell_tty_info);
 988     }
 989   return 0;
 990 }
 991
 992 /* Give the terminal to PGRP.  */
 993 int
 994 give_terminal_to (pgrp, force)
 995      pid_t pgrp;
 996      int force;
 997 {
 998   return 0;
 999 }
1000
1001 /* Stop a pipeline. */
1002 int
1003 stop_pipeline (async, ignore)
1004      int async;
1005      COMMAND *ignore;
1006 {
1007   already_making_children = 0;
1008   return 0;
1009 }
1010
1011 void
1012 start_pipeline ()
1013 {
1014   already_making_children = 1;
1015 }
1016
1017 void
1018 stop_making_children ()
1019 {
1020   already_making_children = 0;
1021 }
1022
1023 /* The name is kind of a misnomer, but it's what the job control code uses. */
1024 void
1025 without_job_control ()
1026 {
1027   stop_making_children ();
1028   last_made_pid = NO_PID;       /* XXX */
1029 }
1030
1031 int
1032 get_job_by_pid (pid, block, ignore)
1033      pid_t pid;
1034      int block;
1035      PROCESS **ignore;
1036 {
1037   int i;
1038
1039   i = find_index_by_pid (pid);
1040   return ((i == NO_PID) ? PROC_BAD : i);
1041 }
1042
1043 /* Print descriptive information about the job with leader pid PID. */
1044 void
1045 describe_pid (pid)
1046      pid_t pid;
1047 {
1048   fprintf (stderr, "%ld\n", (long) pid);
1049 }
1050
1051 int
1052 freeze_jobs_list ()
1053 {
1054   return 0;
1055 }
1056
1057 void
1058 unfreeze_jobs_list ()
1059 {
1060 }
1061
1062 void
1063 set_jobs_list_frozen (s)
1064      int s;
1065 {
1066 }
1067
1068 int
1069 count_all_jobs ()
1070 {
1071   return 0;
1072 }