busybox/archival/libunarchive/open_transformer.c

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/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
/* transformer(), more than meets the eye */
/*
* On MMU machine, the transform_prog is removed by macro magic
* in include/unarchive.h. On NOMMU, transformer is removed.
*/
void FAST_FUNC open_transformer(int fd,
USE_DESKTOP(long long) int FAST_FUNC (*transformer)(int src_fd, int dst_fd),
const char *transform_prog)
{
struct fd_pair fd_pipe;
int pid;
xpiped_pair(fd_pipe);
#if BB_MMU
pid = fork();
if (pid == -1)
bb_perror_msg_and_die("vfork" + 1);
#else
pid = vfork();
if (pid == -1)
bb_perror_msg_and_die("vfork");
#endif
if (pid == 0) {
/* child process */
close(fd_pipe.rd); /* we don't want to read from the parent */
// FIXME: error check?
#if BB_MMU
transformer(fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* send EOF */
close(fd);
}
/* must be _exit! bug was actually seen here */
_exit(EXIT_SUCCESS);
#else
{
char *argv[4];
xmove_fd(fd, 0);
xmove_fd(fd_pipe.wr, 1);
argv[0] = (char*)transform_prog;
argv[1] = (char*)"-cf";
argv[2] = (char*)"-";
argv[3] = NULL;
BB_EXECVP(transform_prog, argv);
bb_perror_msg_and_die("can't exec %s", transform_prog);
}
#endif
/* notreached */
}
/* parent process */
close(fd_pipe.wr); /* don't want to write to the child */
xmove_fd(fd_pipe.rd, fd);
}