/*-
* Copyright (c) 2013-2018 Devin Teske <dteske@FreeBSD.org>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <limits.h>
#include <spawn.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "util.h"
extern char **environ;
static char cmdbuf[CMDBUFMAX] = "";
static char shellcmd[PATH_MAX] = PATH_SHELL;
static char *shellcmd_argv[6] = {
shellcmd,
__DECONST(char *, "-c"),
cmdbuf,
__DECONST(char *, "--"),
shellcmd,
NULL,
};
/*
* Spawn a sh(1) command. Writes the resulting process ID to the pid_t pointed
* at by `pid'. Returns a file descriptor (int) suitable for writing data to
* the spawned command (data written to file descriptor is seen as standard-in
* by the spawned sh(1) command). Returns `-1' if unable to spawn command.
*
* If cmd contains a single "%s" sequence, replace it with label if non-NULL.
*/
int
shell_spawn_pipecmd(const char *cmd, const char *label, pid_t *pid)
{
int error;
int len;
posix_spawn_file_actions_t action;
#if SHELL_SPAWN_DEBUG
unsigned int i;
#endif
int stdin_pipe[2] = { -1, -1 };
/* Populate argument array */
if (label != NULL && fmtcheck(cmd, "%s") == cmd)
len = snprintf(cmdbuf, CMDBUFMAX, cmd, label);
else
len = snprintf(cmdbuf, CMDBUFMAX, "%s", cmd);
if (len >= CMDBUFMAX) {
warnx("%s:%d:%s: cmdbuf[%u] too small to hold cmd argument",
__FILE__, __LINE__, __func__, CMDBUFMAX);
return (-1);
}
/* Open a pipe to communicate with [X]dialog(1) */
if (pipe(stdin_pipe) < 0)
err(EXIT_FAILURE, "%s: pipe(2)", __func__);
/* Fork sh(1) process */
#if SHELL_SPAWN_DEBUG
fprintf(stderr, "%s: spawning `", __func__);
for (i = 0; shellcmd_argv[i] != NULL; i++) {
if (i == 0)
fprintf(stderr, "%s", shellcmd_argv[i]);
else if (i == 2)
fprintf(stderr, " '%s'", shellcmd_argv[i]);
else
fprintf(stderr, " %s", shellcmd_argv[i]);
}
fprintf(stderr, "'\n");
#endif
posix_spawn_file_actions_init(&action);
posix_spawn_file_actions_adddup2(&action, stdin_pipe[0], STDIN_FILENO);
posix_spawn_file_actions_addclose(&action, stdin_pipe[1]);
error = posix_spawnp(pid, shellcmd, &action,
(const posix_spawnattr_t *)NULL, shellcmd_argv, environ);
if (error != 0) err(EXIT_FAILURE, "%s", shellcmd);
return stdin_pipe[1];
}
