mdw@git.distorted.org.uk Git - shells/blob - ushell.c

   1 /* -*-c-*-
   2  *
   3  * $Id: ushell.c,v 1.2 1999/04/21 09:07:55 mdw Exp $
   4  *
   5  * Extract a user's shell
   6  *
   7  * (c) 1999 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Revision history --------------------------------------------------*
  28  *
  29  * $Log: ushell.c,v $
  30  * Revision 1.2  1999/04/21 09:07:55  mdw
  31  * Fiddle with copyright messages so that they're correct.
  32  *
  33  * Revision 1.1.1.1  1999/04/20 00:19:04  mdw
  34  * Initial versions.
  35  *
  36  */
  37
  38 /*----- Header files ------------------------------------------------------*/
  39
  40 #include <errno.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <pwd.h>
  45 #include <sys/types.h>
  46 #include <unistd.h>
  47
  48 /*----- Main code ---------------------------------------------------------*/
  49
  50 static const char *quis;
  51
  52 int main(int argc, char *argv[])
  53 {
  54   struct passwd *pw;
  55
  56   /* --- Resolve the program name --- */
  57
  58   {
  59     char *p, *q;
  60     p = argv[0];
  61     for (q = argv[0]; *q; q++) {
  62       if (*q == '/')
  63         p = q + 1;
  64     }
  65     quis = p;
  66   }
  67
  68   /* --- Get the argument name --- */
  69
  70   if (argc != 2) {
  71     fprintf(stderr, "Usage: %s username\n", quis);
  72     exit(EXIT_FAILURE);
  73   }
  74
  75   /* --- Read the user information --- */
  76
  77   if ((pw = getpwnam(argv[1])) == 0) {
  78     fprintf(stderr, "%s: user `%s' doesn't exist", quis, argv[1]);
  79     exit(EXIT_FAILURE);
  80   }
  81
  82   /* --- Done --- */
  83
  84   puts(pw->pw_shell);
  85   return (0);
  86 }
  87
  88 /*----- That's all, folks -------------------------------------------------*/