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+This file is wait.def, from which is created wait.c.
+It implements the builtin "wait" in Bash.
+
+Copyright (C) 1987-2020 Free Software Foundation, Inc.
+
+This file is part of GNU Bash, the Bourne Again SHell.
+
+Bash is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Bash is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Bash. If not, see <http://www.gnu.org/licenses/>.
+
+$BUILTIN wait
+$FUNCTION wait_builtin
+$DEPENDS_ON JOB_CONTROL
+$PRODUCES wait.c
+$SHORT_DOC wait [-fn] [-p var] [id ...]
+Wait for job completion and return exit status.
+
+Waits for each process identified by an ID, which may be a process ID or a
+job specification, and reports its termination status. If ID is not
+given, waits for all currently active child processes, and the return
+status is zero. If ID is a job specification, waits for all processes
+in that job's pipeline.
+
+If the -n option is supplied, waits for a single job from the list of IDs,
+or, if no IDs are supplied, for the next job to complete and returns its
+exit status.
+
+If the -p option is supplied, the process or job identifier of the job
+for which the exit status is returned is assigned to the variable VAR
+named by the option argument. The variable will be unset initially, before
+any assignment. This is useful only when the -n option is supplied.
+
+If the -f option is supplied, and job control is enabled, waits for the
+specified ID to terminate, instead of waiting for it to change status.
+
+Exit Status:
+Returns the status of the last ID; fails if ID is invalid or an invalid
+option is given, or if -n is supplied and the shell has no unwaited-for
+children.
+$END
+
+$BUILTIN wait
+$FUNCTION wait_builtin
+$DEPENDS_ON !JOB_CONTROL
+$SHORT_DOC wait [pid ...]
+Wait for process completion and return exit status.
+
+Waits for each process specified by a PID and reports its termination status.
+If PID is not given, waits for all currently active child processes,
+and the return status is zero. PID must be a process ID.
+
+Exit Status:
+Returns the status of the last PID; fails if PID is invalid or an invalid
+option is given.
+$END
+
+#include <config.h>
+
+#include "../bashtypes.h"
+#include <signal.h>
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include <chartypes.h>
+
+#include "../bashansi.h"
+
+#include "../shell.h"
+#include "../execute_cmd.h"
+#include "../jobs.h"
+#include "../trap.h"
+#include "../sig.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+extern int wait_signal_received;
+
+procenv_t wait_intr_buf;
+int wait_intr_flag;
+
+static int set_waitlist PARAMS((WORD_LIST *));
+static void unset_waitlist PARAMS((void));
+
+/* Wait for the pid in LIST to stop or die. If no arguments are given, then
+ wait for all of the active background processes of the shell and return
+ 0. If a list of pids or job specs are given, return the exit status of
+ the last one waited for. */
+
+#define WAIT_RETURN(s) \
+ do \
+ { \
+ wait_signal_received = 0; \
+ wait_intr_flag = 0; \
+ return (s);\
+ } \
+ while (0)
+
+int
+wait_builtin (list)
+ WORD_LIST *list;
+{
+ int status, code, opt, nflag, wflags;
+ char *vname;
+ SHELL_VAR *pidvar;
+ struct procstat pstat;
+
+ USE_VAR(list);
+
+ nflag = wflags = 0;
+ vname = NULL;
+ pidvar = (SHELL_VAR *)NULL;
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "fnp:")) != -1)
+ {
+ switch (opt)
+ {
+#if defined (JOB_CONTROL)
+ case 'n':
+ nflag = 1;
+ break;
+ case 'f':
+ wflags |= JWAIT_FORCE;
+ break;
+ case 'p':
+ vname = list_optarg;
+ break;
+#endif
+ CASE_HELPOPT;
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
+ }
+ }
+ list = loptend;
+
+ /* Sanity-check variable name if -p supplied. */
+ if (vname)
+ {
+#if defined (ARRAY_VARS)
+ int arrayflags;
+
+ arrayflags = assoc_expand_once ? (VA_NOEXPAND|VA_ONEWORD) : 0;
+ if (legal_identifier (vname) == 0 && valid_array_reference (vname, arrayflags) == 0)
+#else
+ if (legal_identifier (vname) == 0)
+#endif
+ {
+ sh_invalidid (vname);
+ WAIT_RETURN (EXECUTION_FAILURE);
+ }
+ if (builtin_unbind_variable (vname) == -2)
+ WAIT_RETURN (EXECUTION_FAILURE);
+ }
+
+ /* POSIX.2 says: When the shell is waiting (by means of the wait utility)
+ for asynchronous commands to complete, the reception of a signal for
+ which a trap has been set shall cause the wait utility to return
+ immediately with an exit status greater than 128, after which the trap
+ associated with the signal shall be taken.
+
+ We handle SIGINT here; it's the only one that needs to be treated
+ specially (I think), since it's handled specially in {no,}jobs.c. */
+ wait_intr_flag = 1;
+ code = setjmp_sigs (wait_intr_buf);
+
+ if (code)
+ {
+ last_command_exit_signal = wait_signal_received;
+ status = 128 + wait_signal_received;
+ wait_sigint_cleanup ();
+ WAIT_RETURN (status);
+ }
+
+ opt = first_pending_trap ();
+#if defined (SIGCHLD)
+ /* We special case SIGCHLD when not in posix mode because we don't break
+ out of the wait even when the signal is trapped; we run the trap after
+ the wait completes. See how it's handled in jobs.c:waitchld(). */
+ if (opt == SIGCHLD && posixly_correct == 0)
+ opt = next_pending_trap (opt+1);
+#endif
+ if (opt != -1)
+ {
+ last_command_exit_signal = wait_signal_received = opt;
+ status = opt + 128;
+ WAIT_RETURN (status);
+ }
+
+ /* We support jobs or pids.
+ wait <pid-or-job> [pid-or-job ...] */
+
+#if defined (JOB_CONTROL)
+ if (nflag)
+ {
+ if (list)
+ {
+ opt = set_waitlist (list);
+ if (opt == 0)
+ WAIT_RETURN (127);
+ wflags |= JWAIT_WAITING;
+ }
+
+ status = wait_for_any_job (wflags, &pstat);
+ if (status < 0)
+ status = 127;
+
+ if (vname && status >= 0)
+ bind_var_to_int (vname, pstat.pid);
+ if (list)
+ unset_waitlist ();
+ WAIT_RETURN (status);
+ }
+#endif
+
+ /* But wait without any arguments means to wait for all of the shell's
+ currently active background processes. */
+ if (list == 0)
+ {
+ wait_for_background_pids (&pstat);
+ if (vname)
+ bind_var_to_int (vname, pstat.pid);
+ WAIT_RETURN (EXECUTION_SUCCESS);
+ }
+
+ status = EXECUTION_SUCCESS;
+ while (list)
+ {
+ pid_t pid;
+ char *w;
+ intmax_t pid_value;
+
+ w = list->word->word;
+ if (DIGIT (*w))
+ {
+ if (legal_number (w, &pid_value) && pid_value == (pid_t)pid_value)
+ {
+ pid = (pid_t)pid_value;
+ status = wait_for_single_pid (pid, wflags|JWAIT_PERROR);
+ pstat.pid = pid;
+ pstat.status = status;
+ }
+ else
+ {
+ sh_badpid (w);
+ pstat.pid = NO_PID;
+ pstat.status = 127;
+ WAIT_RETURN (EXECUTION_FAILURE);
+ }
+ }
+#if defined (JOB_CONTROL)
+ else if (*w && *w == '%')
+ /* Must be a job spec. Check it out. */
+ {
+ int job;
+ sigset_t set, oset;
+
+ BLOCK_CHILD (set, oset);
+ job = get_job_spec (list);
+
+ if (INVALID_JOB (job))
+ {
+ if (job != DUP_JOB)
+ sh_badjob (list->word->word);
+ UNBLOCK_CHILD (oset);
+ status = 127; /* As per Posix.2, section 4.70.2 */
+ pstat.pid = NO_PID;
+ pstat.status = status;
+ list = list->next;
+ continue;
+ }
+
+ /* Job spec used. Wait for the last pid in the pipeline. */
+ UNBLOCK_CHILD (oset);
+ status = wait_for_job (job, wflags, &pstat);
+ }
+#endif /* JOB_CONTROL */
+ else
+ {
+ sh_badpid (w);
+ pstat.pid = NO_PID;
+ pstat.status = 127;
+ status = EXECUTION_FAILURE;
+ }
+
+ /* Don't waste time with a longjmp. */
+ if (wait_signal_received)
+ {
+ last_command_exit_signal = wait_signal_received;
+ status = 128 + wait_signal_received;
+ wait_sigint_cleanup ();
+ WAIT_RETURN (status);
+ }
+
+ list = list->next;
+ }
+
+ WAIT_RETURN (status);
+}
+
+#if defined (JOB_CONTROL)
+/* Take each valid pid or jobspec in LIST and mark the corresponding job as
+ J_WAITING, so wait -n knows which jobs to wait for. Return the number of
+ jobs we found. */
+static int
+set_waitlist (list)
+ WORD_LIST *list;
+{
+ sigset_t set, oset;
+ int job, r, njob;
+ intmax_t pid;
+ WORD_LIST *l;
+
+ BLOCK_CHILD (set, oset);
+ njob = 0;
+ for (l = list; l; l = l->next)
+ {
+ job = NO_JOB;
+ job = (l && legal_number (l->word->word, &pid) && pid == (pid_t) pid)
+ ? get_job_by_pid ((pid_t) pid, 0, 0)
+ : get_job_spec (l);
+ if (job == NO_JOB || jobs == 0 || INVALID_JOB (job))
+ {
+ sh_badjob (l->word->word);
+ continue;
+ }
+ /* We don't check yet to see if one of the desired jobs has already
+ terminated, but we could. We wait until wait_for_any_job(). This
+ has the advantage of validating all the arguments. */
+ if ((jobs[job]->flags & J_WAITING) == 0)
+ {
+ njob++;
+ jobs[job]->flags |= J_WAITING;
+ }
+ }
+ UNBLOCK_CHILD (oset);
+ return (njob);
+}
+
+/* Clean up after a call to wait -n jobs */
+static void
+unset_waitlist ()
+{
+ int i;
+ sigset_t set, oset;
+
+ BLOCK_CHILD (set, oset);
+ for (i = 0; i < js.j_jobslots; i++)
+ if (jobs[i] && (jobs[i]->flags & J_WAITING))
+ jobs[i]->flags &= ~J_WAITING;
+ UNBLOCK_CHILD (oset);
+}
+#endif