sbase/chroot.c
FRIGN 6f207dac5f Don't return but _exit after failed exec*() and fork()
Quoting POSIX[0]:
"Care should be taken, also, to call _exit() rather than exit() if exec cannot be used, since
exit() flushes and closes standard I/O channels, thereby damaging the parent process' standard
I/O data structures. (Even with fork(), it is wrong to call exit(), since buffered data would
then be flushed twice.)"

[0]: http://pubs.opengroup.org/onlinepubs/009695399/functions/vfork.html
2015-03-09 01:12:59 +01:00

50 lines
753 B
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include "util.h"
static void
usage(void)
{
eprintf("usage: %s dir [cmd [arg ...]]\n", argv0);
}
int
main(int argc, char *argv[])
{
char *shell[] = { "/bin/sh", "-i", NULL }, *aux, *cmd;
int savederrno;
ARGBEGIN {
default:
usage();
} ARGEND;
if (!argc)
usage();
if ((aux = getenv("SHELL")))
shell[0] = aux;
if (chroot(argv[0]) < 0)
eprintf("chroot %s:", argv[0]);
if (chdir("/") < 0)
eprintf("chdir:");
if (argc == 1) {
cmd = *shell;
execvp(cmd, shell);
} else {
cmd = argv[1];
execvp(cmd, argv + 1);
}
savederrno = errno;
weprintf("execvp %s:", cmd);
_exit(126 + (savederrno == ENOENT));
}