diff options
Diffstat (limited to 'libcrecovery/popen.c')
| -rw-r--r-- | libcrecovery/popen.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/libcrecovery/popen.c b/libcrecovery/popen.c new file mode 100644 index 000000000..73d3c7437 --- /dev/null +++ b/libcrecovery/popen.c @@ -0,0 +1,169 @@ +/* $OpenBSD: popen.c,v 1.17 2005/08/08 08:05:34 espie 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/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> + +#include "defines.h" + +static struct pid { + struct pid *next; + FILE *fp; + pid_t pid; +} *pidlist; + +FILE * +__popen(const char *program, const char *type) +{ + struct pid * volatile cur; + FILE *iop; + int pdes[2]; + pid_t pid; + + if ((*type != 'r' && *type != 'w') || type[1] != '\0') { + 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. */ + { + struct pid *pcur; + /* + * because vfork() instead of fork(), must leak FILE *, + * but luckily we are terminally headed for an execl() + */ + for (pcur = pidlist; pcur; pcur = pcur->next) + close(fileno(pcur->fp)); + + if (*type == 'r') { + int tpdes1 = pdes[1]; + + (void) close(pdes[0]); + /* + * We must NOT modify pdes, due to the + * semantics of vfork. + */ + if (tpdes1 != STDOUT_FILENO) { + (void)dup2(tpdes1, STDOUT_FILENO); + (void)close(tpdes1); + tpdes1 = STDOUT_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", program, (char *)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(FILE *iop) +{ + struct pid *cur, *last; + int pstat; + pid_t pid; + + /* 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); + + (void)fclose(iop); + + 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); +} |