1/* vi: set sw=4 ts=4: */
2/*
3 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
4 */
5
6#include "libbb.h"
7#include "unarchive.h"
8
9/* transformer(), more than meets the eye */
10/*
11 * On MMU machine, the transform_prog is removed by macro magic
12 * in include/unarchive.h. On NOMMU, transformer is removed.
13 */
14void FAST_FUNC open_transformer(int fd,
15	IF_DESKTOP(long long) int FAST_FUNC (*transformer)(int src_fd, int dst_fd),
16	const char *transform_prog)
17{
18	struct fd_pair fd_pipe;
19	int pid;
20
21	xpiped_pair(fd_pipe);
22	pid = BB_MMU ? xfork() : xvfork();
23	if (pid == 0) {
24		/* Child */
25		close(fd_pipe.rd); /* we don't want to read from the parent */
26		// FIXME: error check?
27#if BB_MMU
28		transformer(fd, fd_pipe.wr);
29		if (ENABLE_FEATURE_CLEAN_UP) {
30			close(fd_pipe.wr); /* send EOF */
31			close(fd);
32		}
33		/* must be _exit! bug was actually seen here */
34		_exit(EXIT_SUCCESS);
35#else
36		{
37			char *argv[4];
38			xmove_fd(fd, 0);
39			xmove_fd(fd_pipe.wr, 1);
40			argv[0] = (char*)transform_prog;
41			argv[1] = (char*)"-cf";
42			argv[2] = (char*)"-";
43			argv[3] = NULL;
44			BB_EXECVP(transform_prog, argv);
45			bb_perror_msg_and_die("can't execute '%s'", transform_prog);
46		}
47#endif
48		/* notreached */
49	}
50
51	/* parent process */
52	close(fd_pipe.wr); /* don't want to write to the child */
53	xmove_fd(fd_pipe.rd, fd);
54}
55