chroot.c

   1 /*
   2     Copyright © 2013 Alastair Stuart
   3
   4     This program is open source software: you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation, either version 3 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12     GNU General Public License for more details.
  13 */
  14
  15 #include <stdio.h>
  16 #include <unistd.h>
  17 #include <errno.h>
  18 #include <string.h>
  19
  20 #define VERSION "0.01"
  21
  22 int main(int argc, char* argv[])
  23 {
  24     if (argc == 1) {
  25         fprintf(stderr, "%s: missing operand\n"
  26                         "Run '%s --help' for usage.\n",
  27                         argv[0], argv[0]);
  28         return 1;
  29     }
  30
  31     // flag parsing
  32     int arg = 0;
  33     for (arg = 1; arg < argc; arg++)
  34     {
  35         if (strcmp(argv[arg], "--help") == 0) {
  36             printf("Usage: %s [newroot]\n", argv[0]);
  37             return 0;
  38         } else if (strcmp(argv[arg], "--version") == 0) {
  39             printf("chroot (mutos) v"VERSION"\n");
  40             return 0;
  41         } else {
  42             break;
  43         }
  44     }
  45
  46     chdir(argv[arg]);
  47     int rc = chroot(argv[arg]);
  48         if (rc == -1) {
  49             fprintf(stderr, "%s: cannot change root directory to %s: %s\n", argv[0], argv[arg], strerror(errno));
  50             return 125;
  51         }
  52
  53     return 0;
  54 }