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/*
* Copyright (C) 2013-2014 Robin Gareus <robin@gareus.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h>
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
#define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
#define STDERR_FILENO 2
#endif
extern char **environ;
static void close_fd (int *fd) { if ((*fd) >= 0) close (*fd); *fd = -1; }
int main(int argc, char *argv[]) {
if (argc < 10) {
// TODO: if argv > 3, assume pok[] is given, notifify parent.
// usage() and a man-page (help2man) would not be bad, either :)
return -1;
}
int pok[2];
int pin[2];
int pout[2];
pok[0] = atoi(argv[1]);
pok[1] = atoi(argv[2]);
pin[0] = atoi(argv[3]);
pin[1] = atoi(argv[4]);
pout[0] = atoi(argv[5]);
pout[1] = atoi(argv[6]);
int stderr_mode = atoi(argv[7]);
int nicelevel = atoi(argv[8]);
/* vfork()ed child process - exec external process */
close_fd(&pok[0]);
fcntl(pok[1], F_SETFD, FD_CLOEXEC);
close_fd(&pin[1]);
if (pin[0] != STDIN_FILENO) {
dup2(pin[0], STDIN_FILENO);
}
close_fd(&pin[0]);
close_fd(&pout[0]);
if (pout[1] != STDOUT_FILENO) {
dup2(pout[1], STDOUT_FILENO);
}
if (stderr_mode == 2) {
/* merge STDERR into output */
if (pout[1] != STDERR_FILENO) {
dup2(pout[1], STDERR_FILENO);
}
} else if (stderr_mode == 1) {
/* ignore STDERR */
close(STDERR_FILENO);
} else {
/* keep STDERR */
}
if (pout[1] != STDOUT_FILENO && pout[1] != STDERR_FILENO) {
close_fd(&pout[1]);
}
if (nicelevel !=0) {
nice(nicelevel);
}
/* copy current environment */
char **envp = NULL;
int i=0;
envp = (char **) calloc(1, sizeof(char*));
for (i=0;environ[i];++i) {
envp[i] = strdup(environ[i]);
envp = (char **) realloc(envp, (i+2) * sizeof(char*));
}
envp[i] = 0;
#ifdef HAVE_SIGSET
sigset(SIGPIPE, SIG_DFL);
#else
signal(SIGPIPE, SIG_DFL);
#endif
/* all systems go */
execve(argv[9], &argv[9], envp);
/* if we reach here something went wrong.. */
char buf = 0;
(void) write(pok[1], &buf, 1 );
close_fd(&pok[1]);
#ifdef __clang_analyzer__
// the clang static analyzer warns about a memleak here,
// but we don't care. The OS will clean up after us in a jiffy.
for (i=0; envp && envp[i]; ++i) {
free (envp[i]);
}
free (envp);
#endif
return -1;
}
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