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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) many different people. If you wrote this, please
* acknowledge your work.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libbb.h"
static int gz_use_vfork;
FILE *
gz_open(FILE *compressed_file, int *pid)
{
int unzip_pipe[2];
off_t floc;
int cfile = -1;
gz_use_vfork = (getenv("OPKG_USE_VFORK") != NULL);
if (gz_use_vfork) {
/* Create a new file descriptor for the input stream
* (it *must* be associated with a file), and lseek()
* to the same position in that fd as the stream.
*/
cfile = dup(fileno(compressed_file));
floc = ftello(compressed_file);
lseek(cfile, floc, SEEK_SET);
setenv("GZIP", "--quiet", 0);
}
if (pipe(unzip_pipe)!=0) {
perror_msg("pipe");
return(NULL);
}
/* If we don't flush, we end up with two copies of anything pending,
one from the parent, one from the child */
fflush(stdout);
fflush(stderr);
if (gz_use_vfork) {
*pid = vfork();
} else {
*pid = fork();
}
if (*pid<0) {
perror_msg("fork");
return(NULL);
}
if (*pid==0) {
/* child process */
close(unzip_pipe[0]);
if (gz_use_vfork) {
dup2(unzip_pipe[1], 1);
dup2(cfile, 0);
execlp("gunzip","gunzip",NULL);
/* If we get here, we had a failure */
_exit(EXIT_FAILURE);
} else {
unzip(compressed_file, fdopen(unzip_pipe[1], "w"));
fflush(NULL);
fclose(compressed_file);
close(unzip_pipe[1]);
_exit(EXIT_SUCCESS);
}
}
/* Parent process is executing here */
if (gz_use_vfork) {
close(cfile);
}
close(unzip_pipe[1]);
return(fdopen(unzip_pipe[0], "r"));
}
int
gz_close(int gunzip_pid)
{
int status;
int ret;
if (gz_use_vfork) {
/* The gunzip process remains running in the background if we
* used the vfork()/exec() technique - so we have to kill it
* forcibly. There might be a better way to do this, but that
* affect a lot of other parts of opkg, and this works fine.
*/
if (kill(gunzip_pid, SIGTERM) == -1) {
perror_msg("gz_close(): unable to kill gunzip pid.");
return -1;
}
}
if (waitpid(gunzip_pid, &status, 0) == -1) {
perror_msg("waitpid");
return -1;
}
if (gz_use_vfork) {
/* Bail out here if we used the vfork()/exec() technique. */
return 0;
}
if (WIFSIGNALED(status)) {
error_msg("Unzip process killed by signal %d.\n",
WTERMSIG(status));
return -1;
}
if (!WIFEXITED(status)) {
/* shouldn't happen */
error_msg("Your system is broken: got status %d from waitpid.\n",
status);
return -1;
}
if ((ret = WEXITSTATUS(status))) {
error_msg("Unzip process failed with return code %d.\n",
ret);
return -1;
}
return 0;
}
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