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) 1987-2011 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
  53 #define DEFAULT_CHILD_MAX 32
  54
  55 #if defined (_POSIX_VERSION) || !defined (HAVE_KILLPG)
  56 #  define killpg(pg, sig)               kill(-(pg),(sig))
  57 #endif /* USG || _POSIX_VERSION */
  58
  59 #if !defined (HAVE_SIGINTERRUPT) && !defined (HAVE_POSIX_SIGNALS)
  60 #  define siginterrupt(sig, code)
  61 #endif /* !HAVE_SIGINTERRUPT && !HAVE_POSIX_SIGNALS */
  62
  63 #if defined (HAVE_WAITPID)
  64 #  define WAITPID(pid, statusp, options) waitpid (pid, statusp, options)
  65 #else
  66 #  define WAITPID(pid, statusp, options) wait (statusp)
  67 #endif /* !HAVE_WAITPID */
  68
  69 /* Return the fd from which we are actually getting input. */
  70 #define input_tty() (shell_tty != -1) ? shell_tty : fileno (stderr)
  71
  72 #if !defined (errno)
  73 extern int errno;
  74 #endif /* !errno */
  75
  76 extern int interactive, interactive_shell, login_shell;
  77 extern int subshell_environment;
  78 extern int last_command_exit_value, last_command_exit_signal;
  79 extern int interrupt_immediately;
  80 extern sh_builtin_func_t *this_shell_builtin;
  81 #if defined (HAVE_POSIX_SIGNALS)
  82 extern sigset_t top_level_mask;
  83 #endif
  84 extern procenv_t wait_intr_buf;
  85 extern int wait_intr_flag;
  86 extern int wait_signal_received;
  87
  88 extern void set_original_signal __P((int, SigHandler *));
  89
  90 volatile pid_t last_made_pid = NO_PID;
  91 volatile pid_t last_asynchronous_pid = NO_PID;
  92
  93 static int queue_sigchld, waiting_for_child;    /* dummy declarations */
  94
  95 /* Call this when you start making children. */
  96 int already_making_children = 0;
  97
  98 /* The controlling tty for this shell. */
  99 int shell_tty = -1;
 100
 101 /* If this is non-zero, $LINES and $COLUMNS are reset after every process
 102    exits from get_tty_state(). */
 103 int check_window_size = CHECKWINSIZE_DEFAULT;
 104
 105 /* We don't have job control. */
 106 int job_control = 0;
 107
 108 int running_in_background = 0;  /* can't tell without job control */
 109
 110 /* STATUS and FLAGS are only valid if pid != NO_PID
 111    STATUS is only valid if (flags & PROC_RUNNING) == 0 */
 112 struct proc_status {
 113   pid_t pid;
 114   int status;   /* Exit status of PID or 128 + fatal signal number */
 115   int flags;
 116 };
 117
 118 /* Values for proc_status.flags */
 119 #define PROC_RUNNING    0x01
 120 #define PROC_NOTIFIED   0x02
 121 #define PROC_ASYNC      0x04
 122 #define PROC_SIGNALED   0x10
 123
 124 /* Return values from find_status_by_pid */
 125 #define PROC_BAD         -1
 126 #define PROC_STILL_ALIVE -2
 127
 128 static struct proc_status *pid_list = (struct proc_status *)NULL;
 129 static int pid_list_size;
 130 static int wait_sigint_received;
 131
 132 static long child_max = -1L;
 133
 134 static void alloc_pid_list __P((void));
 135 static int find_proc_slot __P((pid_t));
 136 static int find_index_by_pid __P((pid_t));
 137 static int find_status_by_pid __P((pid_t));
 138 static int process_exit_status __P((WAIT));
 139 static int find_termsig_by_pid __P((pid_t));
 140 static int get_termsig __P((WAIT));
 141 static void set_pid_status __P((pid_t, WAIT));
 142 static void set_pid_flags __P((pid_t, int));
 143 static void unset_pid_flags __P((pid_t, int));
 144 static int get_pid_flags __P((pid_t));
 145 static void add_pid __P((pid_t, int));
 146 static void mark_dead_jobs_as_notified __P((int));
 147
 148 static sighandler wait_sigint_handler __P((int));
 149 static char *j_strsignal __P((int));
 150
 151 #if defined (HAVE_WAITPID)
 152 static void reap_zombie_children __P((void));
 153 #endif
 154
 155 #if !defined (HAVE_SIGINTERRUPT) && defined (HAVE_POSIX_SIGNALS)
 156 static int siginterrupt __P((int, int));
 157 #endif
 158
 159 static void restore_sigint_handler __P((void));
 160
 161 /* Allocate new, or grow existing PID_LIST. */
 162 static void
 163 alloc_pid_list ()
 164 {
 165   register int i;
 166   int old = pid_list_size;
 167
 168   pid_list_size += 10;
 169   pid_list = (struct proc_status *)xrealloc (pid_list, pid_list_size * sizeof (struct proc_status));
 170
 171   /* None of the newly allocated slots have process id's yet. */
 172   for (i = old; i < pid_list_size; i++)
 173     {
 174       pid_list[i].pid = NO_PID;
 175       pid_list[i].status = pid_list[i].flags = 0;
 176     }
 177 }
 178
 179 /* Return the offset within the PID_LIST array of an empty slot.  This can
 180    create new slots if all of the existing slots are taken. */
 181 static int
 182 find_proc_slot (pid)
 183      pid_t pid;
 184 {
 185   register int i;
 186
 187   for (i = 0; i < pid_list_size; i++)
 188     if (pid_list[i].pid == NO_PID || pid_list[i].pid == pid)
 189       return (i);
 190
 191   if (i == pid_list_size)
 192     alloc_pid_list ();
 193
 194   return (i);
 195 }
 196
 197 /* Return the offset within the PID_LIST array of a slot containing PID,
 198    or the value NO_PID if the pid wasn't found. */
 199 static int
 200 find_index_by_pid (pid)
 201      pid_t pid;
 202 {
 203   register int i;
 204
 205   for (i = 0; i < pid_list_size; i++)
 206     if (pid_list[i].pid == pid)
 207       return (i);
 208
 209   return (NO_PID);
 210 }
 211
 212 /* Return the status of PID as looked up in the PID_LIST array.  A
 213    return value of PROC_BAD indicates that PID wasn't found. */
 214 static int
 215 find_status_by_pid (pid)
 216      pid_t pid;
 217 {
 218   int i;
 219
 220   i = find_index_by_pid (pid);
 221   if (i == NO_PID)
 222     return (PROC_BAD);
 223   if (pid_list[i].flags & PROC_RUNNING)
 224     return (PROC_STILL_ALIVE);
 225   return (pid_list[i].status);
 226 }
 227
 228 static int
 229 process_exit_status (status)
 230      WAIT status;
 231 {
 232   if (WIFSIGNALED (status))
 233     return (128 + WTERMSIG (status));
 234   else
 235     return (WEXITSTATUS (status));
 236 }
 237
 238 /* Return the status of PID as looked up in the PID_LIST array.  A
 239    return value of PROC_BAD indicates that PID wasn't found. */
 240 static int
 241 find_termsig_by_pid (pid)
 242      pid_t pid;
 243 {
 244   int i;
 245
 246   i = find_index_by_pid (pid);
 247   if (i == NO_PID)
 248     return (0);
 249   if (pid_list[i].flags & PROC_RUNNING)
 250     return (0);
 251   return (get_termsig ((WAIT)pid_list[i].status));
 252 }
 253
 254 /* Set LAST_COMMAND_EXIT_SIGNAL depending on STATUS.  If STATUS is -1, look
 255    up PID in the pid array and set LAST_COMMAND_EXIT_SIGNAL appropriately
 256    depending on its flags and exit status. */
 257 static int
 258 get_termsig (status)
 259      WAIT status;
 260 {
 261   if (WIFSTOPPED (status) == 0 && WIFSIGNALED (status))
 262     return (WTERMSIG (status));
 263   else
 264     return (0);
 265 }
 266
 267 /* Give PID the status value STATUS in the PID_LIST array. */
 268 static void
 269 set_pid_status (pid, status)
 270      pid_t pid;
 271      WAIT status;
 272 {
 273   int slot;
 274
 275 #if defined (COPROCESS_SUPPORT)
 276   coproc_pidchk (pid, status);
 277 #endif
 278
 279   slot = find_index_by_pid (pid);
 280   if (slot == NO_PID)
 281     return;
 282
 283   pid_list[slot].status = process_exit_status (status);
 284   pid_list[slot].flags &= ~PROC_RUNNING;
 285   if (WIFSIGNALED (status))
 286     pid_list[slot].flags |= PROC_SIGNALED;
 287   /* If it's not a background process, mark it as notified so it gets
 288      cleaned up. */
 289   if ((pid_list[slot].flags & PROC_ASYNC) == 0)
 290     pid_list[slot].flags |= PROC_NOTIFIED;
 291 }
 292
 293 /* Give PID the flags FLAGS in the PID_LIST array. */
 294 static void
 295 set_pid_flags (pid, flags)
 296      pid_t pid;
 297      int flags;
 298 {
 299   int slot;
 300
 301   slot = find_index_by_pid (pid);
 302   if (slot == NO_PID)
 303     return;
 304
 305   pid_list[slot].flags |= flags;
 306 }
 307
 308 /* Unset FLAGS for PID in the pid list */
 309 static void
 310 unset_pid_flags (pid, flags)
 311      pid_t pid;
 312      int flags;
 313 {
 314   int slot;
 315
 316   slot = find_index_by_pid (pid);
 317   if (slot == NO_PID)
 318     return;
 319
 320   pid_list[slot].flags &= ~flags;
 321 }
 322
 323 /* Return the flags corresponding to PID in the PID_LIST array. */
 324 static int
 325 get_pid_flags (pid)
 326      pid_t pid;
 327 {
 328   int slot;
 329
 330   slot = find_index_by_pid (pid);
 331   if (slot == NO_PID)
 332     return 0;
 333
 334   return (pid_list[slot].flags);
 335 }
 336
 337 static void
 338 add_pid (pid, async)
 339      pid_t pid;
 340      int async;
 341 {
 342   int slot;
 343
 344   slot = find_proc_slot (pid);
 345
 346   pid_list[slot].pid = pid;
 347   pid_list[slot].status = -1;
 348   pid_list[slot].flags = PROC_RUNNING;
 349   if (async)
 350     pid_list[slot].flags |= PROC_ASYNC;
 351 }
 352
 353 static void
 354 mark_dead_jobs_as_notified (force)
 355      int force;
 356 {
 357   register int i, ndead;
 358
 359   /* first, count the number of non-running async jobs if FORCE == 0 */
 360   for (i = ndead = 0; force == 0 && i < pid_list_size; i++)
 361     {
 362       if (pid_list[i].pid == NO_PID)
 363         continue;
 364       if (((pid_list[i].flags & PROC_RUNNING) == 0) &&
 365            (pid_list[i].flags & PROC_ASYNC))
 366         ndead++;
 367     }
 368
 369   if (child_max < 0)
 370     child_max = getmaxchild ();
 371   if (child_max < 0)
 372     child_max = DEFAULT_CHILD_MAX;
 373
 374   if (force == 0 && ndead <= child_max)
 375     return;
 376
 377   /* If FORCE == 0, we just mark as many non-running async jobs as notified
 378      to bring us under the CHILD_MAX limit. */
 379   for (i = 0; i < pid_list_size; i++)
 380     {
 381       if (pid_list[i].pid == NO_PID)
 382         continue;
 383       if (((pid_list[i].flags & PROC_RUNNING) == 0) &&
 384            pid_list[i].pid != last_asynchronous_pid)
 385         {
 386           pid_list[i].flags |= PROC_NOTIFIED;
 387           if (force == 0 && (pid_list[i].flags & PROC_ASYNC) && --ndead <= child_max)
 388             break;
 389         }
 390     }
 391 }
 392
 393 /* Remove all dead, notified jobs from the pid_list. */
 394 int
 395 cleanup_dead_jobs ()
 396 {
 397   register int i;
 398
 399 #if defined (HAVE_WAITPID)
 400   reap_zombie_children ();
 401 #endif
 402
 403   for (i = 0; i < pid_list_size; i++)
 404     {
 405       if (pid_list[i].pid != NO_PID &&
 406             (pid_list[i].flags & PROC_RUNNING) == 0 &&
 407             (pid_list[i].flags & PROC_NOTIFIED))
 408         pid_list[i].pid = NO_PID;
 409     }
 410
 411 #if defined (COPROCESS_SUPPORT)
 412   coproc_reap ();
 413 #endif
 414
 415   return 0;
 416 }
 417
 418 void
 419 reap_dead_jobs ()
 420 {
 421   mark_dead_jobs_as_notified (0);
 422   cleanup_dead_jobs ();
 423 }
 424
 425 /* Initialize the job control mechanism, and set up the tty stuff. */
 426 int
 427 initialize_job_control (force)
 428      int force;
 429 {
 430   shell_tty = fileno (stderr);
 431
 432   if (interactive)
 433     get_tty_state ();
 434   return 0;
 435 }
 436
 437 /* Setup this shell to handle C-C, etc. */
 438 void
 439 initialize_job_signals ()
 440 {
 441   set_signal_handler (SIGINT, sigint_sighandler);
 442
 443   /* If this is a login shell we don't wish to be disturbed by
 444      stop signals. */
 445   if (login_shell)
 446     ignore_tty_job_signals ();
 447 }
 448
 449 #if defined (HAVE_WAITPID)
 450 /* Collect the status of all zombie children so that their system
 451    resources can be deallocated. */
 452 static void
 453 reap_zombie_children ()
 454 {
 455 #  if defined (WNOHANG)
 456   pid_t pid;
 457   WAIT status;
 458
 459   CHECK_TERMSIG;
 460   CHECK_WAIT_INTR;
 461   while ((pid = waitpid (-1, (int *)&status, WNOHANG)) > 0)
 462     set_pid_status (pid, status);
 463 #  endif /* WNOHANG */
 464   CHECK_TERMSIG;
 465   CHECK_WAIT_INTR;
 466 }
 467 #endif /* WAITPID */
 468
 469 #if !defined (HAVE_SIGINTERRUPT) && defined (HAVE_POSIX_SIGNALS)
 470
 471 #if !defined (SA_RESTART)
 472 #  define SA_RESTART 0
 473 #endif
 474
 475 static int
 476 siginterrupt (sig, flag)
 477      int sig, flag;
 478 {
 479   struct sigaction act;
 480
 481   sigaction (sig, (struct sigaction *)NULL, &act);
 482
 483   if (flag)
 484     act.sa_flags &= ~SA_RESTART;
 485   else
 486     act.sa_flags |= SA_RESTART;
 487
 488   return (sigaction (sig, &act, (struct sigaction *)NULL));
 489 }
 490 #endif /* !HAVE_SIGINTERRUPT && HAVE_POSIX_SIGNALS */
 491
 492 /* Fork, handling errors.  Returns the pid of the newly made child, or 0.
 493    COMMAND is just for remembering the name of the command; we don't do
 494    anything else with it.  ASYNC_P says what to do with the tty.  If
 495    non-zero, then don't give it away. */
 496 pid_t
 497 make_child (command, async_p)
 498      char *command;
 499      int async_p;
 500 {
 501   pid_t pid;
 502   int forksleep;
 503
 504   /* Discard saved memory. */
 505   if (command)
 506     free (command);
 507
 508   start_pipeline ();
 509
 510 #if defined (BUFFERED_INPUT)
 511   /* If default_buffered_input is active, we are reading a script.  If
 512      the command is asynchronous, we have already duplicated /dev/null
 513      as fd 0, but have not changed the buffered stream corresponding to
 514      the old fd 0.  We don't want to sync the stream in this case. */
 515   if (default_buffered_input != -1 && (!async_p || default_buffered_input > 0))
 516     sync_buffered_stream (default_buffered_input);
 517 #endif /* BUFFERED_INPUT */
 518
 519   /* XXX - block SIGTERM here and unblock in child after fork resets the
 520      set of pending signals? */
 521   RESET_SIGTERM;
 522
 523   /* Create the child, handle severe errors.  Retry on EAGAIN. */
 524   forksleep = 1;
 525   while ((pid = fork ()) < 0 && errno == EAGAIN && forksleep < FORKSLEEP_MAX)
 526     {
 527       sys_error ("fork: retry");
 528       RESET_SIGTERM;
 529
 530 #if defined (HAVE_WAITPID)
 531       /* Posix systems with a non-blocking waitpid () system call available
 532          get another chance after zombies are reaped. */
 533       reap_zombie_children ();
 534       if (forksleep > 1 && sleep (forksleep) != 0)
 535         break;
 536 #else
 537       if (sleep (forksleep) != 0)
 538         break;
 539 #endif /* HAVE_WAITPID */
 540       forksleep <<= 1;
 541     }
 542
 543   if (pid != 0)
 544     RESET_SIGTERM;
 545
 546   if (pid < 0)
 547     {
 548       sys_error ("fork");
 549       last_command_exit_value = EX_NOEXEC;
 550       throw_to_top_level ();
 551     }
 552
 553   if (pid == 0)
 554     {
 555 #if defined (BUFFERED_INPUT)
 556       unset_bash_input (0);
 557 #endif /* BUFFERED_INPUT */
 558
 559       CLRINTERRUPT;     /* XXX - children have their own interrupt state */
 560
 561 #if defined (HAVE_POSIX_SIGNALS)
 562       /* Restore top-level signal mask. */
 563       sigprocmask (SIG_SETMASK, &top_level_mask, (sigset_t *)NULL);
 564 #endif
 565
 566 #if 0
 567       /* Ignore INT and QUIT in asynchronous children. */
 568       if (async_p)
 569         last_asynchronous_pid = getpid ();
 570 #endif
 571
 572       default_tty_job_signals ();
 573     }
 574   else
 575     {
 576       /* In the parent. */
 577
 578       last_made_pid = pid;
 579
 580       if (async_p)
 581         last_asynchronous_pid = pid;
 582
 583       add_pid (pid, async_p);
 584     }
 585   return (pid);
 586 }
 587
 588 void
 589 ignore_tty_job_signals ()
 590 {
 591 #if defined (SIGTSTP)
 592   set_signal_handler (SIGTSTP, SIG_IGN);
 593   set_signal_handler (SIGTTIN, SIG_IGN);
 594   set_signal_handler (SIGTTOU, SIG_IGN);
 595 #endif
 596 }
 597
 598 void
 599 default_tty_job_signals ()
 600 {
 601 #if defined (SIGTSTP)
 602   if (signal_is_trapped (SIGTSTP) == 0 && signal_is_hard_ignored (SIGTSTP))
 603     set_signal_handler (SIGTSTP, SIG_IGN);
 604   else
 605     set_signal_handler (SIGTSTP, SIG_DFL);
 606   if (signal_is_trapped (SIGTTIN) == 0 && signal_is_hard_ignored (SIGTTIN))
 607     set_signal_handler (SIGTTIN, SIG_IGN);
 608   else
 609     set_signal_handler (SIGTTIN, SIG_DFL);
 610   if (signal_is_trapped (SIGTTOU) == 0 && signal_is_hard_ignored (SIGTTOU))
 611     set_signal_handler (SIGTTOU, SIG_IGN);
 612   else
 613     set_signal_handler (SIGTTOU, SIG_DFL);
 614 #endif
 615 }
 616
 617 /* Called once in a parent process. */
 618 void
 619 get_original_tty_job_signals ()
 620 {
 621   static int fetched = 0;
 622
 623   if (fetched == 0)
 624     {
 625 #if defined (SIGTSTP)
 626       if (interactive_shell)
 627         {
 628           set_original_signal (SIGTSTP, SIG_DFL);
 629           set_original_signal (SIGTTIN, SIG_DFL);
 630           set_original_signal (SIGTTOU, SIG_DFL);
 631         }
 632       else
 633         {
 634           get_original_signal (SIGTSTP);
 635           get_original_signal (SIGTTIN);
 636           get_original_signal (SIGTTOU);
 637         }
 638 #endif
 639       fetched = 1;
 640     }
 641 }
 642
 643 /* Wait for a single pid (PID) and return its exit status.  Called by
 644    the wait builtin. */
 645 int
 646 wait_for_single_pid (pid, flags)
 647      pid_t pid;
 648      int flags;
 649 {
 650   pid_t got_pid;
 651   WAIT status;
 652   int pstatus;
 653
 654   pstatus = find_status_by_pid (pid);
 655
 656   if (pstatus == PROC_BAD)
 657     {
 658       internal_error (_("wait: pid %ld is not a child of this shell"), (long)pid);
 659       return (127);
 660     }
 661
 662   if (pstatus != PROC_STILL_ALIVE)
 663     {
 664       if (pstatus > 128)
 665         last_command_exit_signal = find_termsig_by_pid (pid);
 666       return (pstatus);
 667     }
 668
 669   siginterrupt (SIGINT, 1);
 670   while ((got_pid = WAITPID (pid, &status, 0)) != pid)
 671     {
 672       CHECK_TERMSIG;
 673       CHECK_WAIT_INTR;
 674       if (got_pid < 0)
 675         {
 676           if (errno != EINTR && errno != ECHILD)
 677             {
 678               siginterrupt (SIGINT, 0);
 679               sys_error ("wait");
 680             }
 681           break;
 682         }
 683       else if (got_pid > 0)
 684         set_pid_status (got_pid, status);
 685     }
 686
 687   if (got_pid > 0)
 688     {
 689       set_pid_status (got_pid, status);
 690       set_pid_flags (got_pid, PROC_NOTIFIED);
 691     }
 692
 693   siginterrupt (SIGINT, 0);
 694   QUIT;
 695
 696   return (got_pid > 0 ? process_exit_status (status) : -1);
 697 }
 698
 699 /* Wait for all of the shell's children to exit.  Called by the `wait'
 700    builtin. */
 701 void
 702 wait_for_background_pids ()
 703 {
 704   pid_t got_pid;
 705   WAIT status;
 706
 707   /* If we aren't using job control, we let the kernel take care of the
 708      bookkeeping for us.  wait () will return -1 and set errno to ECHILD
 709      when there are no more unwaited-for child processes on both
 710      4.2 BSD-based and System V-based systems. */
 711
 712   siginterrupt (SIGINT, 1);
 713
 714   /* Wait for ECHILD */
 715   while ((got_pid = WAITPID (-1, &status, 0)) != -1)
 716     set_pid_status (got_pid, status);
 717
 718   if (errno != EINTR && errno != ECHILD)
 719     {
 720       siginterrupt (SIGINT, 0);
 721       sys_error("wait");
 722     }
 723
 724   siginterrupt (SIGINT, 0);
 725   QUIT;
 726
 727   mark_dead_jobs_as_notified (1);
 728   cleanup_dead_jobs ();
 729 }
 730
 731 void
 732 wait_sigint_cleanup ()
 733 {
 734 }
 735
 736 /* Make OLD_SIGINT_HANDLER the SIGINT signal handler. */
 737 #define INVALID_SIGNAL_HANDLER (SigHandler *)wait_for_background_pids
 738 static SigHandler *old_sigint_handler = INVALID_SIGNAL_HANDLER;
 739
 740 static void
 741 restore_sigint_handler ()
 742 {
 743   if (old_sigint_handler != INVALID_SIGNAL_HANDLER)
 744     {
 745       set_signal_handler (SIGINT, old_sigint_handler);
 746       old_sigint_handler = INVALID_SIGNAL_HANDLER;
 747     }
 748 }
 749
 750 /* Handle SIGINT while we are waiting for children in a script to exit.
 751    All interrupts are effectively ignored by the shell, but allowed to
 752    kill a running job. */
 753 static sighandler
 754 wait_sigint_handler (sig)
 755      int sig;
 756 {
 757   SigHandler *sigint_handler;
 758
 759   /* If we got a SIGINT while in `wait', and SIGINT is trapped, do
 760      what POSIX.2 says (see builtins/wait.def for more info). */
 761   if (this_shell_builtin && this_shell_builtin == wait_builtin &&
 762       signal_is_trapped (SIGINT) &&
 763       ((sigint_handler = trap_to_sighandler (SIGINT)) == trap_handler))
 764     {
 765       last_command_exit_value = 128+SIGINT;
 766       restore_sigint_handler ();
 767       interrupt_immediately = 0;
 768       trap_handler (SIGINT);    /* set pending_traps[SIGINT] */
 769       wait_signal_received = SIGINT;
 770       SIGRETURN (0);
 771     }
 772
 773   if (interrupt_immediately)
 774     {
 775       last_command_exit_value = EXECUTION_FAILURE;
 776       restore_sigint_handler ();
 777       ADDINTERRUPT;
 778       QUIT;
 779     }
 780
 781   wait_sigint_received = 1;
 782
 783   SIGRETURN (0);
 784 }
 785
 786 static char *
 787 j_strsignal (s)
 788      int s;
 789 {
 790   static char retcode_name_buffer[64] = { '\0' };
 791   char *x;
 792
 793   x = strsignal (s);
 794   if (x == 0)
 795     {
 796       x = retcode_name_buffer;
 797       sprintf (x, "Signal %d", s);
 798     }
 799   return x;
 800 }
 801
 802 /* Wait for pid (one of our children) to terminate.  This is called only
 803    by the execution code in execute_cmd.c. */
 804 int
 805 wait_for (pid)
 806      pid_t pid;
 807 {
 808   int return_val, pstatus;
 809   pid_t got_pid;
 810   WAIT status;
 811
 812   pstatus = find_status_by_pid (pid);
 813
 814   if (pstatus == PROC_BAD)
 815     return (0);
 816
 817   if (pstatus != PROC_STILL_ALIVE)
 818     {
 819       if (pstatus > 128)
 820         last_command_exit_signal = find_termsig_by_pid (pid);
 821       return (pstatus);
 822     }
 823
 824   /* If we are running a script, ignore SIGINT while we're waiting for
 825      a child to exit.  The loop below does some of this, but not all. */
 826   wait_sigint_received = 0;
 827   if (interactive_shell == 0)
 828     old_sigint_handler = set_signal_handler (SIGINT, wait_sigint_handler);
 829
 830   while ((got_pid = WAITPID (-1, &status, 0)) != pid) /* XXX was pid now -1 */
 831     {
 832       CHECK_TERMSIG;
 833       CHECK_WAIT_INTR;
 834       if (got_pid < 0 && errno == ECHILD)
 835         {
 836 #if !defined (_POSIX_VERSION)
 837           status.w_termsig = status.w_retcode = 0;
 838 #else
 839           status = 0;
 840 #endif /* _POSIX_VERSION */
 841           break;
 842         }
 843       else if (got_pid < 0 && errno != EINTR)
 844         programming_error ("wait_for(%ld): %s", (long)pid, strerror(errno));
 845       else if (got_pid > 0)
 846         set_pid_status (got_pid, status);
 847     }
 848
 849   if (got_pid > 0)
 850     set_pid_status (got_pid, status);
 851
 852 #if defined (HAVE_WAITPID)
 853   if (got_pid >= 0)
 854     reap_zombie_children ();
 855 #endif /* HAVE_WAITPID */
 856
 857   CHECK_TERMSIG;
 858   CHECK_WAIT_INTR;
 859
 860   if (interactive_shell == 0)
 861     {
 862       SigHandler *temp_handler;
 863
 864       temp_handler = old_sigint_handler;
 865       restore_sigint_handler ();
 866
 867       /* If the job exited because of SIGINT, make sure the shell acts as if
 868          it had received one also. */
 869       if (WIFSIGNALED (status) && (WTERMSIG (status) == SIGINT))
 870         {
 871
 872           if (maybe_call_trap_handler (SIGINT) == 0)
 873             {
 874               if (temp_handler == SIG_DFL)
 875                 termsig_handler (SIGINT);
 876               else if (temp_handler != INVALID_SIGNAL_HANDLER && temp_handler != SIG_IGN)
 877                 (*temp_handler) (SIGINT);
 878             }
 879         }
 880     }
 881
 882   /* Default return value. */
 883   /* ``a full 8 bits of status is returned'' */
 884   return_val = process_exit_status (status);
 885   last_command_exit_signal = get_termsig (status);
 886
 887 #if defined (DONT_REPORT_SIGPIPE) && defined (DONT_REPORT_SIGTERM)
 888 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGPIPE && (x) != SIGTERM)
 889 #elif !defined (DONT_REPORT_SIGPIPE) && !defined (DONT_REPORT_SIGTERM)
 890 #  define REPORTSIG(x) ((x) != SIGINT)
 891 #elif defined (DONT_REPORT_SIGPIPE)
 892 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGPIPE)
 893 #else
 894 #  define REPORTSIG(x) ((x) != SIGINT && (x) != SIGTERM)
 895 #endif
 896
 897   if ((WIFSTOPPED (status) == 0) && WIFSIGNALED (status) && REPORTSIG(WTERMSIG (status)))
 898     {
 899       fprintf (stderr, "%s", j_strsignal (WTERMSIG (status)));
 900       if (WIFCORED (status))
 901         fprintf (stderr, _(" (core dumped)"));
 902       fprintf (stderr, "\n");
 903     }
 904
 905   if (interactive_shell && subshell_environment == 0)
 906     {
 907       if (WIFSIGNALED (status) || WIFSTOPPED (status))
 908         set_tty_state ();
 909       else
 910         get_tty_state ();
 911     }
 912   else if (interactive_shell == 0 && subshell_environment == 0 && check_window_size)
 913     get_new_window_size (0, (int *)0, (int *)0);
 914
 915   return (return_val);
 916 }
 917
 918 /* Send PID SIGNAL.  Returns -1 on failure, 0 on success.  If GROUP is non-zero,
 919    or PID is less than -1, then kill the process group associated with PID. */
 920 int
 921 kill_pid (pid, signal, group)
 922      pid_t pid;
 923      int signal, group;
 924 {
 925   int result;
 926
 927   if (pid < -1)
 928     {
 929       pid = -pid;
 930       group = 1;
 931     }
 932   result = group ? killpg (pid, signal) : kill (pid, signal);
 933   return (result);
 934 }
 935
 936 static TTYSTRUCT shell_tty_info;
 937 static int got_tty_state;
 938
 939 /* Fill the contents of shell_tty_info with the current tty info. */
 940 int
 941 get_tty_state ()
 942 {
 943   int tty;
 944
 945   tty = input_tty ();
 946   if (tty != -1)
 947     {
 948       ttgetattr (tty, &shell_tty_info);
 949       got_tty_state = 1;
 950       if (check_window_size)
 951         get_new_window_size (0, (int *)0, (int *)0);
 952     }
 953   return 0;
 954 }
 955
 956 /* Make the current tty use the state in shell_tty_info. */
 957 int
 958 set_tty_state ()
 959 {
 960   int tty;
 961
 962   tty = input_tty ();
 963   if (tty != -1)
 964     {
 965       if (got_tty_state == 0)
 966         return 0;
 967       ttsetattr (tty, &shell_tty_info);
 968     }
 969   return 0;
 970 }
 971
 972 /* Give the terminal to PGRP.  */
 973 int
 974 give_terminal_to (pgrp, force)
 975      pid_t pgrp;
 976      int force;
 977 {
 978   return 0;
 979 }
 980
 981 /* Stop a pipeline. */
 982 int
 983 stop_pipeline (async, ignore)
 984      int async;
 985      COMMAND *ignore;
 986 {
 987   already_making_children = 0;
 988   return 0;
 989 }
 990
 991 void
 992 start_pipeline ()
 993 {
 994   already_making_children = 1;
 995 }
 996
 997 void
 998 stop_making_children ()
 999 {
1000   already_making_children = 0;
1001 }
1002
1003 /* The name is kind of a misnomer, but it's what the job control code uses. */
1004 void
1005 without_job_control ()
1006 {
1007   stop_making_children ();
1008   last_made_pid = NO_PID;       /* XXX */
1009 }
1010
1011 int
1012 get_job_by_pid (pid, block)
1013      pid_t pid;
1014      int block;
1015 {
1016   int i;
1017
1018   i = find_index_by_pid (pid);
1019   return ((i == NO_PID) ? PROC_BAD : i);
1020 }
1021
1022 /* Print descriptive information about the job with leader pid PID. */
1023 void
1024 describe_pid (pid)
1025      pid_t pid;
1026 {
1027   fprintf (stderr, "%ld\n", (long) pid);
1028 }
1029
1030 int
1031 freeze_jobs_list ()
1032 {
1033   return 0;
1034 }
1035
1036 void
1037 unfreeze_jobs_list ()
1038 {
1039 }
1040
1041 int
1042 count_all_jobs ()
1043 {
1044   return 0;
1045 }