LXR busybox/archival/libunarchive/open

   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        USE_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
  23#if BB_MMU
  24        pid = fork();
  25        if (pid == -1)
  26                bb_perror_msg_and_die("vfork" + 1);
  27#else
  28        pid = vfork();
  29        if (pid == -1)
  30                bb_perror_msg_and_die("vfork");
  31#endif
  32
  33        if (pid == 0) {
  34                /* child process */
  35                close(fd_pipe.rd); /* we don't want to read from the parent */
  36                // FIXME: error check?
  37#if BB_MMU
  38                transformer(fd, fd_pipe.wr);
  39                if (ENABLE_FEATURE_CLEAN_UP) {
  40                        close(fd_pipe.wr); /* send EOF */
  41                        close(fd);
  42                }
  43                /* must be _exit! bug was actually seen here */
  44                _exit(EXIT_SUCCESS);
  45#else
  46                {
  47                        char *argv[4];
  48                        xmove_fd(fd, 0);
  49                        xmove_fd(fd_pipe.wr, 1);
  50                        argv[0] = (char*)transform_prog;
  51                        argv[1] = (char*)"-cf";
  52                        argv[2] = (char*)"-";
  53                        argv[3] = NULL;
  54                        BB_EXECVP(transform_prog, argv);
  55                        bb_perror_msg_and_die("can't exec %s", transform_prog);
  56                }
  57#endif
  58                /* notreached */
  59        }
  60
  61        /* parent process */
  62        close(fd_pipe.wr); /* don't want to write to the child */
  63        xmove_fd(fd_pipe.rd, fd);
  64}
  65