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