mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-10 03:54:48 +00:00
232 lines
6.2 KiB
C
232 lines
6.2 KiB
C
/* $NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1988, 1993, 2006
|
|
* 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.
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
FUNCTION
|
|
<<popen>>, <<pclose>>---tie a stream to a command string
|
|
|
|
INDEX
|
|
popen
|
|
INDEX
|
|
pclose
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <stdio.h>
|
|
FILE *popen(const char *<[s]>, const char *<[mode]>);
|
|
|
|
int pclose(FILE *<[f]>);
|
|
|
|
DESCRIPTION
|
|
Use <<popen>> to create a stream to a child process executing a
|
|
command string <<*<[s]>>> as processed by <</bin/sh>> on your system.
|
|
The argument <[mode]> must start with either `<<r>>', where the stream
|
|
reads from the child's <<stdout>>, or `<<w>>', where the stream writes
|
|
to the child's <<stdin>>. As an extension, <[mode]> may also contain
|
|
`<<e>>' to set the close-on-exec bit of the parent's file descriptor.
|
|
The stream created by <<popen>> must be closed by <<pclose>> to avoid
|
|
resource leaks.
|
|
|
|
Streams created by prior calls to <<popen>> are not visible in
|
|
subsequent <<popen>> children, regardless of the close-on-exec bit.
|
|
|
|
Use ``<<system(NULL)>>'' to test whether your system has <</bin/sh>>
|
|
available.
|
|
|
|
RETURNS
|
|
<<popen>> returns a file stream opened with the specified <[mode]>,
|
|
or <<NULL>> if a child process could not be created. <<pclose>>
|
|
returns -1 if the stream was not created by <<popen>> or if the
|
|
application used <<wait>> or similar to steal the status; otherwise
|
|
it returns the exit status of the child which can be interpreted
|
|
in the same manner as a status obtained by <<waitpid>>.
|
|
|
|
PORTABILITY
|
|
POSIX.2 requires <<popen>> and <<pclose>>, but only specifies a mode
|
|
of just <<r>> or <<w>>. Where <<sh>> is found is left unspecified.
|
|
|
|
Supporting OS subroutines required: <<_exit>>, <<_execve>>, <<_fork_r>>,
|
|
<<_wait_r>>, <<pipe>>, <<fcntl>>, <<sbrk>>.
|
|
*/
|
|
|
|
#ifndef _NO_POPEN
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
#if 0
|
|
static char sccsid[] = "@(#)popen.c 8.1 (Berkeley) 6/4/93";
|
|
#else
|
|
static char rcsid[] = "$NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $";
|
|
#endif
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/types.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>
|
|
#include <fcntl.h>
|
|
|
|
static struct pid {
|
|
struct pid *next;
|
|
FILE *fp;
|
|
pid_t pid;
|
|
} *pidlist;
|
|
|
|
FILE *
|
|
_DEFUN(popen, (program, type),
|
|
const char *program _AND
|
|
const char *type)
|
|
{
|
|
struct pid *cur, *last;
|
|
FILE *iop;
|
|
int pdes[2], pid;
|
|
|
|
if ((*type != 'r' && *type != 'w')
|
|
|| (type[1]
|
|
#ifdef HAVE_FCNTL
|
|
&& (type[2] || (type[1] != 'e'))
|
|
#endif
|
|
)) {
|
|
errno = EINVAL;
|
|
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]);
|
|
}
|
|
if (pdes[0] != STDOUT_FILENO) {
|
|
(void) close(pdes[0]);
|
|
}
|
|
} else {
|
|
if (pdes[0] != STDIN_FILENO) {
|
|
(void)dup2(pdes[0], STDIN_FILENO);
|
|
(void)close(pdes[0]);
|
|
}
|
|
(void)close(pdes[1]);
|
|
}
|
|
/* Close all fd's created by prior popen. */
|
|
for (last = NULL, cur = pidlist; cur;
|
|
last = cur, cur = cur->next)
|
|
(void)close (fileno (cur->fp));
|
|
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]);
|
|
}
|
|
|
|
#ifdef HAVE_FCNTL
|
|
/* Mark pipe cloexec if requested. */
|
|
if (type[1] == 'e')
|
|
fcntl (fileno (iop), F_SETFD,
|
|
fcntl (fileno (iop), F_GETFD, 0) | FD_CLOEXEC);
|
|
#endif /* HAVE_FCNTL */
|
|
|
|
/* 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
|
|
_DEFUN(pclose, (iop),
|
|
FILE *iop)
|
|
{
|
|
register struct pid *cur, *last;
|
|
int 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);
|
|
|
|
do {
|
|
pid = waitpid(cur->pid, &pstat, 0);
|
|
} while (pid == -1 && errno == EINTR);
|
|
|
|
/* 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);
|
|
}
|
|
|
|
#endif /* !_NO_POPEN */
|