yesno.c

   1 /* yesno.c -- read a yes/no response from stdin
   2    Copyright (C) 1990, 1998 Free Software Foundation, Inc.
   3
   4    This program is free 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 2, or (at your option)
   7    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    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #if HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #include <ctype.h>
  23 #if HAVE_STDLIB_H
  24 # include <stdlib.h>
  25 #endif
  26 #include <stdio.h>
  27
  28 /* Read one line from standard input
  29    and return nonzero if that line begins with y or Y,
  30    otherwise return 0. */
  31
  32 int rpmatch ();
  33
  34 int
  35 yesno ()
  36 {
  37   /* We make some assumptions here:
  38      a) leading white space in the response are not vital
  39      b) the first 128 characters of the answer are enough (the rest can
  40         be ignored)
  41      I cannot think for a situation where this is not ok.  --drepper@gnu  */
  42   char buf[128];
  43   int len = 0;
  44   int c;
  45
  46   while ((c = getchar ()) != EOF && c != '\n')
  47     if ((len > 0 && len < 127) || (len == 0 && !isspace (c)))
  48       buf[len++] = c;
  49   buf[len] = '\0';
  50
  51   return rpmatch (buf) == 1;
  52 }