277 lines
5.9 KiB
C
277 lines
5.9 KiB
C
/* $Xorg: signals.c,v 1.4 2001/02/09 02:06:01 xorgcvs Exp $ */
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/******************************************************************************
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Copyright 1994, 1998 The Open Group
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Permission to use, copy, modify, distribute, and sell this software and its
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documentation for any purpose is hereby granted without fee, provided that
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the above copyright notice appear in all copies and that both that
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copyright notice and this permission notice appear in supporting
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documentation.
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of The Open Group shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from The Open Group.
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******************************************************************************/
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/* $XFree86: xc/programs/xsm/signals.c,v 3.5 2001/12/08 18:33:45 herrb Exp $ */
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#include <stdlib.h>
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#include <X11/Xos.h>
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#include <X11/Xfuncs.h>
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#include <X11/Intrinsic.h>
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#include <X11/SM/SMlib.h>
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#include "save.h"
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#include <errno.h>
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#ifdef USG
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#ifndef __TYPES__
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#include <sys/types.h> /* forgot to protect it... */
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#define __TYPES__
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#endif /* __TYPES__ */
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#else
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#if defined(_POSIX_SOURCE) && defined(MOTOROLA)
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#undef _POSIX_SOURCE
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#include <sys/types.h>
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#define _POSIX_SOURCE
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#else
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#include <sys/types.h>
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#endif
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#endif /* USG */
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#ifdef X_POSIX_C_SOURCE
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#define _POSIX_C_SOURCE X_POSIX_C_SOURCE
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#include <signal.h>
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#include <sys/wait.h>
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#undef _POSIX_C_SOURCE
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#else
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#if defined(X_NOT_POSIX) || defined(_POSIX_SOURCE)
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#include <signal.h>
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#include <sys/wait.h>
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#else
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#define _POSIX_SOURCE
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#include <signal.h>
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#ifdef SCO325
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#include <sys/procset.h>
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#include <sys/siginfo.h>
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#endif
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#include <sys/wait.h>
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#undef _POSIX_SOURCE
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#endif
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#endif
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#include "list.h"
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#include "save.h"
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#if defined(X_NOT_POSIX) && defined(SIGNALRETURNSINT)
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#define SIGVAL int
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#else
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#define SIGVAL void
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#endif
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#ifndef X_NOT_POSIX
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#define USE_POSIX_WAIT
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#endif
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#if defined(linux) || defined(SYSV)
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#define USE_SYSV_SIGNALS
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#endif
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#if defined(SCO) || defined(ISC)
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#undef SIGTSTP /* defined, but not the BSD way */
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#endif
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#if defined(X_NOT_POSIX) && defined(SYSV)
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#define SIGNALS_RESET_WHEN_CAUGHT
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#endif
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#include <stddef.h>
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#include "xsm.h"
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int checkpoint_from_signal = 0;
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static SIGVAL
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Signal(int sig, SIGVAL (*handler)(int))
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{
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#ifndef X_NOT_POSIX
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struct sigaction sigact, osigact;
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sigact.sa_handler = handler;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = 0;
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sigaction(sig, &sigact, &osigact);
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# if defined(SIGNALRETURNSINT)
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return osigact.sa_handler;
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# endif
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#else
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# if defined(SIGNALRETURNSINT)
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return
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# endif
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signal(sig, handler);
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#endif
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}
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void
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sig_child_handler (int sig)
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{
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int pid, olderrno = errno;
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#if !defined(USE_POSIX_WAIT) && (defined(USE_SYSV_SIGNALS) && \
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(defined(CRAY) || !defined(SIGTSTP)))
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wait (NULL);
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#endif
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#ifdef SIGNALS_RESET_WHEN_CAUGHT
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Signal (SIGCHLD, sig_child_handler);
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#endif
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/*
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* The wait() above must come before re-establishing the signal handler.
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* In between this time, a new child might have died. If we can do
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* a non-blocking wait, we can check for this race condition. If we
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* don't have non-blocking wait, we lose.
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*/
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do
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{
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#ifdef USE_POSIX_WAIT
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pid = waitpid (-1, NULL, WNOHANG);
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#else
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#if defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP))
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/* cannot do non-blocking wait */
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pid = 0;
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#else
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union wait status;
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pid = wait3 (&status, WNOHANG, (struct rusage *)NULL);
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#endif
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#endif /* USE_POSIX_WAIT else */
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}
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while (pid > 0);
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errno = olderrno;
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}
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void
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sig_term_handler(int sig)
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{
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XtNoticeSignal(sig_term_id);
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}
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void
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xt_sig_term_handler (XtPointer closure, XtSignalId *id)
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{
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wantShutdown = 1;
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checkpoint_from_signal = 1;
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DoSave (SmSaveLocal, SmInteractStyleNone, 1 /* fast */);
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}
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void sig_usr1_handler(int sig)
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{
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XtNoticeSignal(sig_usr1_id);
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}
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void
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xt_sig_usr1_handler (XtPointer closure, XtSignalId *id)
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{
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wantShutdown = 0;
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checkpoint_from_signal = 1;
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DoSave (SmSaveLocal, SmInteractStyleNone, 0 /* fast */);
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}
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void
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register_signals (XtAppContext appContext)
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{
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/*
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* Ignore SIGPIPE
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*/
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Signal (SIGPIPE, SIG_IGN);
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/*
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* If child process dies, call our handler
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*/
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Signal (SIGCHLD, sig_child_handler);
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/*
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* If we get a SIGTERM, do shutdown, fast, local, no interact
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*/
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Signal (SIGTERM, sig_term_handler);
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sig_term_id = XtAppAddSignal(appContext, xt_sig_term_handler, NULL);
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/*
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* If we get a SIGUSR1, do checkpoint, local, no interact
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*/
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Signal (SIGUSR1, sig_usr1_handler);
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sig_usr1_id = XtAppAddSignal(appContext, xt_sig_usr1_handler, NULL);
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}
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int
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execute_system_command (char *s)
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{
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int stat;
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#ifdef X_NOT_POSIX
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/*
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* Non-POSIX system() uses wait(). We must disable our sig child
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* handler because if it catches the signal, system() will block
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* forever in wait().
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*/
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int pid;
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Signal (SIGCHLD, SIG_IGN);
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#endif
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stat = system (s);
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#ifdef X_NOT_POSIX
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/*
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* Re-enable our sig child handler. We might have missed some signals,
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* so do non-blocking waits until there are no signals left.
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*/
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Signal (SIGCHLD, sig_child_handler);
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#if !(defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP)))
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do
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{
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union wait status;
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pid = wait3 (&status, WNOHANG, (struct rusage *)NULL);
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} while (pid > 0);
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#endif
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#endif /* X_NOT_POSIX */
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return (stat);
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}
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