lib/yesno.c

   1 /* yesno.c -- read a yes/no response from stdin
   2    Copyright (C) 1990, 1998, 2001 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 #include "unlocked-io.h"
  28
  29 /* Read one line from standard input
  30    and return nonzero if that line begins with y or Y,
  31    otherwise return 0. */
  32
  33 int rpmatch ();
  34
  35 int
  36 yesno ()
  37 {
  38   /* We make some assumptions here:
  39      a) leading white space in the response are not vital
  40      b) the first 128 characters of the answer are enough (the rest can
  41         be ignored)
  42      I cannot think for a situation where this is not ok.  --drepper@gnu  */
  43   char buf[128];
  44   int len = 0;
  45   int c;
  46
  47   while ((c = getchar ()) != EOF && c != '\n')
  48     if ((len > 0 && len < 127) || (len == 0 && !isspace (c)))
  49       buf[len++] = c;
  50   buf[len] = '\0';
  51
  52   return rpmatch (buf) == 1;
  53 }