mypopen.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1999 by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <libgen.h>
#include "global.h" /* pid_t, SIGTYPE, shell, and basename() */
#define tst(a, b) (*mode == 'r'? (b) : (a))
#define RDR 0
#define WTR 1
static pid_t popen_pid[20];
static SIGTYPE (*tstat)();
FILE *
mypopen(char *cmd, char *mode)
{
int p[2];
pid_t *poptr;
int myside, yourside;
pid_t pid;
if (pipe(p) < 0)
return (NULL);
myside = tst(p[WTR], p[RDR]);
yourside = tst(p[RDR], p[WTR]);
if ((pid = fork()) > 0) {
tstat = signal(SIGTSTP, SIG_DFL);
} else if (pid == 0) {
/* myside and yourside reverse roles in child */
int stdio;
/* close all pipes from other popen's */
for (poptr = popen_pid; poptr < popen_pid+20; poptr++) {
if (*poptr)
(void) close(poptr - popen_pid);
}
stdio = tst(0, 1);
(void) close(myside);
(void) close(stdio);
(void) fcntl(yourside, F_DUPFD, stdio);
(void) close(yourside);
(void) execlp(shell, basename(shell), "-c", cmd, 0);
_exit(1);
}
if (pid == -1)
return (NULL);
popen_pid[myside] = pid;
(void) close(yourside);
return (fdopen(myside, mode));
}
int
mypclose(FILE *ptr)
{
int f;
pid_t r;
int status;
SIGTYPE (*hstat)(), (*istat)(), (*qstat)();
f = fileno(ptr);
(void) fclose(ptr);
istat = signal(SIGINT, SIG_IGN);
qstat = signal(SIGQUIT, SIG_IGN);
hstat = signal(SIGHUP, SIG_IGN);
while ((r = wait(&status)) != popen_pid[f] && r != -1) {
}
if (r == -1)
status = -1;
(void) signal(SIGINT, istat);
(void) signal(SIGQUIT, qstat);
(void) signal(SIGHUP, hstat);
(void) signal(SIGTSTP, tstat);
/* mark this pipe closed */
popen_pid[f] = 0;
return (status);
}