161 lines
4.3 KiB
C
161 lines
4.3 KiB
C
/*
|
|
* Copyright (c) 1988, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software written by Ken Arnold and
|
|
* published in UNIX Review, Vol. 6, No. 8.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static char sccsid[] = "@(#)popen.c 8.1 (Berkeley) 6/4/93";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/wait.h>
|
|
|
|
#include <signal.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <paths.h>
|
|
|
|
static struct pid {
|
|
struct pid *next;
|
|
FILE *fp;
|
|
pid_t pid;
|
|
} *pidlist;
|
|
|
|
FILE *
|
|
popen(program, type)
|
|
const char *program;
|
|
const char *type;
|
|
{
|
|
struct pid *cur;
|
|
FILE *iop;
|
|
int pdes[2], pid;
|
|
|
|
if (*type != 'r' && *type != 'w' || type[1])
|
|
return (NULL);
|
|
|
|
if ((cur = malloc(sizeof(struct pid))) == NULL)
|
|
return (NULL);
|
|
|
|
if (pipe(pdes) < 0) {
|
|
free(cur);
|
|
return (NULL);
|
|
}
|
|
|
|
switch (pid = vfork()) {
|
|
case -1: /* Error. */
|
|
(void)close(pdes[0]);
|
|
(void)close(pdes[1]);
|
|
free(cur);
|
|
return (NULL);
|
|
/* NOTREACHED */
|
|
case 0: /* Child. */
|
|
if (*type == 'r') {
|
|
if (pdes[1] != STDOUT_FILENO) {
|
|
(void)dup2(pdes[1], STDOUT_FILENO);
|
|
(void)close(pdes[1]);
|
|
}
|
|
(void) close(pdes[0]);
|
|
} else {
|
|
if (pdes[0] != STDIN_FILENO) {
|
|
(void)dup2(pdes[0], STDIN_FILENO);
|
|
(void)close(pdes[0]);
|
|
}
|
|
(void)close(pdes[1]);
|
|
}
|
|
execl(_PATH_BSHELL, "sh", "-c", program, NULL);
|
|
_exit(127);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/* Parent; assume fdopen can't fail. */
|
|
if (*type == 'r') {
|
|
iop = fdopen(pdes[0], type);
|
|
(void)close(pdes[1]);
|
|
} else {
|
|
iop = fdopen(pdes[1], type);
|
|
(void)close(pdes[0]);
|
|
}
|
|
|
|
/* Link into list of file descriptors. */
|
|
cur->fp = iop;
|
|
cur->pid = pid;
|
|
cur->next = pidlist;
|
|
pidlist = cur;
|
|
|
|
return (iop);
|
|
}
|
|
|
|
/*
|
|
* pclose --
|
|
* Pclose returns -1 if stream is not associated with a `popened' command,
|
|
* if already `pclosed', or waitpid returns an error.
|
|
*/
|
|
int
|
|
pclose(iop)
|
|
FILE *iop;
|
|
{
|
|
register struct pid *cur, *last;
|
|
int omask;
|
|
union wait pstat;
|
|
pid_t pid;
|
|
|
|
(void)fclose(iop);
|
|
|
|
/* Find the appropriate file pointer. */
|
|
for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
|
|
if (cur->fp == iop)
|
|
break;
|
|
if (cur == NULL)
|
|
return (-1);
|
|
|
|
/* Get the status of the process. */
|
|
omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
|
|
do {
|
|
pid = waitpid(cur->pid, (int *) &pstat, 0);
|
|
} while (pid == -1 && errno == EINTR);
|
|
(void)sigsetmask(omask);
|
|
|
|
/* Remove the entry from the linked list. */
|
|
if (last == NULL)
|
|
pidlist = cur->next;
|
|
else
|
|
last->next = cur->next;
|
|
free(cur);
|
|
|
|
return (pid == -1 ? -1 : pstat.w_status);
|
|
}
|