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/*******************************************************************************
* Copyright (c) 2003, 2008 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
#include "exec0.h"
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <libgen.h>
#include <stdlib.h>
/* from pfind.c */
extern char *pfind(const char *name);
pid_t
exec0(const char *path, char *const argv[], char *const envp[],
const char *dirpath, int channels[3])
{
int pipe0[2], pipe1[2], pipe2[2];
pid_t childpid;
char *full_path;
/*
* We use pfind() to check that the program exists and is an executable.
* If not pass the error up. Also execve() wants a full path.
*/
full_path = pfind(path);
if (full_path == NULL) {
fprintf(stderr, "Unable to find full path for \"%s\"\n", (path) ? path : "");
return -1;
}
/*
* Make sure we can create our pipes before forking.
*/
if (channels != NULL) {
if (pipe(pipe0) < 0 || pipe(pipe1) < 0 || pipe(pipe2) < 0) {
fprintf(stderr, "%s(%d): returning due to error.\n",
__FUNCTION__, __LINE__);
free(full_path);
return -1;
}
}
childpid = fork();
if (childpid < 0) {
fprintf(stderr, "%s(%d): returning due to error: %s\n",
__FUNCTION__, __LINE__, strerror(errno));
free(full_path);
return -1;
} else if (childpid == 0) { /* child */
char *ptr;
chdir(dirpath);
if (channels != NULL) {
/* Close the write end of pipe0 */
if (close(pipe0[1]) == -1)
perror("close(pipe0[1])");
/* Close the read end of pipe1 */
if (close(pipe1[0]) == -1)
perror("close(pipe1[0])");
/* Close the read end of pipe2 */
if (close(pipe2[0]) == -1)
perror("close(pipe2[0]))");
/* redirections */
dup2(pipe0[0], STDIN_FILENO); /* dup stdin */
dup2(pipe1[1], STDOUT_FILENO); /* dup stdout */
dup2(pipe2[1], STDERR_FILENO); /* dup stderr */
}
/* Close all the fd's in the child */
{
int fdlimit = sysconf(_SC_OPEN_MAX);
int fd = 3;
while (fd < fdlimit)
close(fd++);
}
if (envp[0] == NULL) {
execv(full_path, argv);
} else {
execve(full_path, argv, envp);
}
_exit(127);
} else if (childpid != 0) { /* parent */
char b;
if (channels != NULL) {
/* close the read end of pipe1 */
if (close(pipe0[0]) == -1)
perror("close(pipe0[0])");
/* close the write end of pipe2 */
if (close(pipe1[1]) == -1)
perror("close(pipe1[1])");
/* close the write end of pipe2 */
if (close(pipe2[1]) == -1)
perror("close(pipe2[1])");
channels[0] = pipe0[1]; /* Output Stream. */
channels[1] = pipe1[0]; /* Input Stream. */
channels[2] = pipe2[0]; /* Input Stream. */
}
free(full_path);
return childpid;
}
free(full_path);
return -1; /*NOT REACHED */
}
int wait0(pid_t pid)
{
int status;
int val = -1;
if (pid < 0 || waitpid(pid, &status, 0) < 0)
return -1;
if (WIFEXITED(status)) {
val = WEXITSTATUS(status);
}
return val;
}
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