/* See svn.gna.org/viewcvs/etoile/trunk/Etoile/LiveCD/uchroot.c for terms of use.  */
#include <stdio.h>
#include <stdlib.h>
#include <pwd.h>
int main(int argc, char * argv[])
{
    if(argc < 4)
    {
        printf("Usage: %s {username} {directory} {program} [arguments]\n", argv[0]);
        return 1;
    }
    /* Parse arguments */
    struct passwd * pass = getpwnam(argv[1]);
    if(pass == NULL)
    {
        printf("Unknown user %s\n", argv[1]);
        return 2;
    }
    /* Set the required UID */
    chdir(argv[2]);
    if(chroot(argv[2])
        ||
        setgid(pass->pw_gid)
        ||
        setuid(pass->pw_uid))
    {
        printf("%s must be run as root. Current uid=%d, euid=%d\n",
               argv[0],
               (int)getuid(),
               (int)geteuid()
               );
        return 3;
    }
    char buf[100];
    return execv(argv[3], argv + 3);
}