| /* $NetBSD: popen.c,v 1.32 2012/06/25 22:32:43 abs Exp $ */ |
| |
| /* |
| * 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. 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. |
| */ |
| |
| #include <sys/cdefs.h> |
| #if defined(LIBC_SCCS) && !defined(lint) |
| #if 0 |
| static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 5/3/95"; |
| #else |
| __RCSID("$NetBSD: popen.c,v 1.32 2012/06/25 22:32:43 abs Exp $"); |
| #endif |
| #endif /* LIBC_SCCS and not lint */ |
| |
| #include "namespace.h" |
| #include <sys/param.h> |
| #include <sys/wait.h> |
| #include <sys/socket.h> |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <paths.h> |
| #include <signal.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| |
| #include "env.h" |
| #include "reentrant.h" |
| |
| #ifdef __weak_alias |
| __weak_alias(popen,_popen) |
| __weak_alias(pclose,_pclose) |
| #endif |
| |
| static struct pid { |
| struct pid *next; |
| FILE *fp; |
| #ifdef _REENTRANT |
| int fd; |
| #endif |
| pid_t pid; |
| } *pidlist; |
| |
| #ifdef _REENTRANT |
| static rwlock_t pidlist_lock = RWLOCK_INITIALIZER; |
| #endif |
| |
| FILE * |
| popen(const char *command, const char *type) |
| { |
| struct pid *cur, *old; |
| FILE *iop; |
| const char * volatile xtype = type; |
| int pdes[2], pid, serrno; |
| volatile int twoway; |
| int flags; |
| |
| _DIAGASSERT(command != NULL); |
| _DIAGASSERT(xtype != NULL); |
| |
| flags = strchr(xtype, 'e') ? O_CLOEXEC : 0; |
| if (strchr(xtype, '+')) { |
| int stype = flags ? (SOCK_STREAM | SOCK_CLOEXEC) : SOCK_STREAM; |
| twoway = 1; |
| xtype = "r+"; |
| if (socketpair(AF_LOCAL, stype, 0, pdes) < 0) |
| return NULL; |
| } else { |
| twoway = 0; |
| xtype = strrchr(xtype, 'r') ? "r" : "w"; |
| if (pipe2(pdes, flags) == -1) |
| return NULL; |
| } |
| |
| if ((cur = malloc(sizeof(struct pid))) == NULL) { |
| (void)close(pdes[0]); |
| (void)close(pdes[1]); |
| errno = ENOMEM; |
| return (NULL); |
| } |
| |
| (void)rwlock_rdlock(&pidlist_lock); |
| (void)__readlockenv(); |
| switch (pid = vfork()) { |
| case -1: /* Error. */ |
| serrno = errno; |
| (void)__unlockenv(); |
| (void)rwlock_unlock(&pidlist_lock); |
| free(cur); |
| (void)close(pdes[0]); |
| (void)close(pdes[1]); |
| errno = serrno; |
| return (NULL); |
| /* NOTREACHED */ |
| case 0: /* Child. */ |
| /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams |
| from previous popen() calls that remain open in the |
| parent process are closed in the new child process. */ |
| for (old = pidlist; old; old = old->next) |
| #ifdef _REENTRANT |
| close(old->fd); /* don't allow a flush */ |
| #else |
| close(fileno(old->fp)); /* don't allow a flush */ |
| #endif |
| |
| if (*xtype == 'r') { |
| (void)close(pdes[0]); |
| if (pdes[1] != STDOUT_FILENO) { |
| (void)dup2(pdes[1], STDOUT_FILENO); |
| (void)close(pdes[1]); |
| } |
| if (twoway) |
| (void)dup2(STDOUT_FILENO, STDIN_FILENO); |
| } else { |
| (void)close(pdes[1]); |
| if (pdes[0] != STDIN_FILENO) { |
| (void)dup2(pdes[0], STDIN_FILENO); |
| (void)close(pdes[0]); |
| } |
| } |
| |
| execl(_PATH_BSHELL, "sh", "-c", command, NULL); |
| _exit(127); |
| /* NOTREACHED */ |
| } |
| (void)__unlockenv(); |
| |
| /* Parent; assume fdopen can't fail. */ |
| if (*xtype == 'r') { |
| iop = fdopen(pdes[0], xtype); |
| #ifdef _REENTRANT |
| cur->fd = pdes[0]; |
| #endif |
| (void)close(pdes[1]); |
| } else { |
| iop = fdopen(pdes[1], xtype); |
| #ifdef _REENTRANT |
| cur->fd = pdes[1]; |
| #endif |
| (void)close(pdes[0]); |
| } |
| |
| /* Link into list of file descriptors. */ |
| cur->fp = iop; |
| cur->pid = pid; |
| cur->next = pidlist; |
| pidlist = cur; |
| (void)rwlock_unlock(&pidlist_lock); |
| |
| 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(FILE *iop) |
| { |
| struct pid *cur, *last; |
| int pstat; |
| pid_t pid; |
| |
| _DIAGASSERT(iop != NULL); |
| |
| rwlock_wrlock(&pidlist_lock); |
| |
| /* Find the appropriate file pointer. */ |
| for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next) |
| if (cur->fp == iop) |
| break; |
| if (cur == NULL) { |
| (void)rwlock_unlock(&pidlist_lock); |
| return (-1); |
| } |
| |
| (void)fclose(iop); |
| |
| /* Remove the entry from the linked list. */ |
| if (last == NULL) |
| pidlist = cur->next; |
| else |
| last->next = cur->next; |
| |
| (void)rwlock_unlock(&pidlist_lock); |
| |
| do { |
| pid = waitpid(cur->pid, &pstat, 0); |
| } while (pid == -1 && errno == EINTR); |
| |
| free(cur); |
| |
| return (pid == -1 ? -1 : pstat); |
| } |