busybox/archival/libunarchive/open_transformer.c
Denis Vlasenko 3da5572bfa *: introduce and use xvfork()
function                                             old     new   delta
time_main                                           1052    1285    +233
crontab_main                                         623     856    +233
ifupdown_main                                       2202    2403    +201
xvfork                                                 -      20     +20
passwd_main                                         1049    1053      +4
grave                                               1068    1066      -2
script_main                                          935     921     -14
vfork_or_die                                          20       -     -20
vfork_compressor                                     206     175     -31
open_as_user                                         109       -    -109
popen2                                               218       -    -218
edit_file                                            910     690    -220
run_command                                          268       -    -268
------------------------------------------------------------------------------
(add/remove: 1/4 grow/shrink: 4/4 up/down: 691/-882)         Total: -191 bytes
2008-07-01 10:40:41 +00:00

66 lines
1.5 KiB
C

/* 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.
*/
int FAST_FUNC open_transformer(int src_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("can't fork");
#else
pid = xvfork();
#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(src_fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* Send EOF */
close(src_fd);
}
/* must be _exit! bug was actually seen here */
_exit(EXIT_SUCCESS);
#else
{
char *argv[4];
xmove_fd(src_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 */
//TODO: get rid of return value (become void)?
xmove_fd(fd_pipe.rd, src_fd);
return src_fd;
}