b487e9d356
by W.Richard Ste vens. EINTR handling suggested by bde@freebsd.org). Code cleanup: 1. Add missing return type. 2. Replace 'union wait' by int. 3. Use Posix-style signal handling instead of signal(). 4. Use fork() instead of deprecated vfork(). 5. Block signals before fork()'ing, instead of after. 6. Return -1 if fork() fails, instead of 0. 7. Add EINTR handling for waitpid() call. Also add claim of Posix conformance to man page.
92 lines
3.3 KiB
C
92 lines
3.3 KiB
C
/*
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* Copyright (c) 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)system.c 8.1 (Berkeley) 6/4/93";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <unistd.h>
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#include <paths.h>
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#include <errno.h>
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int system(command)
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const char *command;
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{
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pid_t pid;
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int pstat;
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struct sigaction ign, intact, quitact;
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sigset_t newsigblock, oldsigblock;
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if (!command) /* just checking... */
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return(1);
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/*
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* Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
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* existing signal dispositions.
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*/
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ign.sa_handler = SIG_IGN;
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(void)sigemptyset(&ign.sa_mask);
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ign.sa_flags = 0;
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(void)sigaction(SIGINT, &ign, &intact);
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(void)sigaction(SIGQUIT, &ign, &quitact);
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(void)sigemptyset(&newsigblock);
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sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
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switch(pid = fork()) {
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case -1: /* error */
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break;
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case 0: /* child */
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/*
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* Restore original signal dispositions and exec the command.
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*/
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(void)sigaction(SIGINT, &intact, NULL);
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(void)sigaction(SIGQUIT, &quitact, NULL);
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(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
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execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
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_exit(127);
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default: /* parent */
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do {
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pid = waitpid(pid, &pstat, 0);
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} while (pid == -1 && errno == EINTR);
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break;
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}
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(void)sigaction(SIGINT, &intact, NULL);
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(void)sigaction(SIGQUIT, &quitact, NULL);
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(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
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return(pid == -1 ? -1 : pstat);
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}
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