134 lines
3.9 KiB
C
134 lines
3.9 KiB
C
/*
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* Copyright (c) 1988 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software written by Ken Arnold and
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* published in UNIX Review, Vol. 6, No. 8.
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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 = "from: @(#)popen.c 5.15 (Berkeley) 2/23/91";*/
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static char *rcsid = "$Id: popen.c,v 1.5 1993/08/26 00:44:55 jtc Exp $";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/param.h>
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#include <sys/wait.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <paths.h>
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static pid_t *pids;
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FILE *
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popen(command, type)
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const char *command;
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const char *type;
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{
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FILE *iop;
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int pdes[2], fds, pid;
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if (*type != 'r' && *type != 'w' || type[1]) {
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errno = EINVAL;
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return (NULL);
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}
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if (pids == NULL) {
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if ((fds = getdtablesize()) <= 0)
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return (NULL);
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if ((pids = (pid_t *)malloc((u_int)(fds * sizeof(int)))) == NULL)
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return (NULL);
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bzero((char *)pids, fds * sizeof(pid_t));
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}
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if (pipe(pdes) < 0)
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return (NULL);
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switch (pid = vfork()) {
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case -1: /* error */
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(void) close(pdes[0]);
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(void) close(pdes[1]);
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return (NULL);
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/* NOTREACHED */
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case 0: /* child */
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if (*type == 'r') {
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if (pdes[1] != STDOUT_FILENO) {
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(void) dup2(pdes[1], STDOUT_FILENO);
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(void) close(pdes[1]);
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}
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(void) close(pdes[0]);
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} else {
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if (pdes[0] != STDIN_FILENO) {
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(void) dup2(pdes[0], STDIN_FILENO);
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(void) close(pdes[0]);
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}
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(void) close(pdes[1]);
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}
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execl(_PATH_BSHELL, "sh", "-c", command, (char *) 0);
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_exit(127);
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/* NOTREACHED */
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}
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/* parent; assume fdopen can't fail... */
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if (*type == 'r') {
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iop = fdopen(pdes[0], type);
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(void) close(pdes[1]);
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} else {
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iop = fdopen(pdes[1], type);
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(void) close(pdes[0]);
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}
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pids[fileno(iop)] = pid;
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return (iop);
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}
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int
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pclose(iop)
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FILE *iop;
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{
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register int fdes;
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int omask;
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int pstat;
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pid_t pid;
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/*
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* pclose returns -1 if stream is not associated with a
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* `popened' command, if already `pclosed', or waitpid
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* returns an error.
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*/
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if (pids == NULL || pids[fdes = fileno(iop)] == 0)
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return (-1);
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(void) fclose(iop);
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do {
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pid = waitpid(pids[fdes], &pstat, 0);
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} while (pid == -1 && errno == EINTR);
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pids[fdes] = 0;
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return (pid == -1 ? -1 : pstat);
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}
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