source: MondoRescue/branches/2.2.9/mindi-busybox/archival/libarchive/open_transformer.c

/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"
#include "archive.h"

/* transformer(), more than meets the eye */
/*
 * On MMU machine, the transform_prog is removed by macro magic
 * in include/archive.h. On NOMMU, transformer is removed.
 */
void FAST_FUNC open_transformer(int fd,
    IF_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);
    pid = BB_MMU ? xfork() : xvfork();
    if (pid == 0) {
        /* Child */
        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 execute '%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);
}