lib/yesno.c

   1 /* yesno.c -- read a yes/no response from stdin
   2
   3    Copyright (C) 1990, 1998, 2001, 2003-2024 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 #include "yesno.h"
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24
  25 /* Return true if we read an affirmative line from standard input.
  26
  27    Since this function uses stdin, it is suggested that the caller not
  28    use STDIN_FILENO directly, and also that the line
  29    atexit(close_stdin) be added to main().  */
  30
  31 bool
  32 yesno (void)
  33 {
  34   bool yes;
  35
  36 #if ENABLE_NLS
  37   char *response = NULL;
  38   size_t response_size = 0;
  39   ssize_t response_len = getline (&response, &response_size, stdin);
  40
  41   if (response_len <= 0)
  42     yes = false;
  43   else
  44     {
  45       /* Remove EOL if present as that's not part of the matched response,
  46          and not matched by $ for example.  */
  47       if (response[response_len - 1] == '\n')
  48         response[response_len - 1] = '\0';
  49       yes = (0 < rpmatch (response));
  50     }
  51
  52   free (response);
  53 #else
  54   /* Test against "^[yY]", hardcoded to avoid requiring getline,
  55      regex, and rpmatch.  */
  56   int c = getchar ();
  57   yes = (c == 'y' || c == 'Y');
  58   while (c != '\n' && c != EOF)
  59     c = getchar ();
  60 #endif
  61
  62   return yes;
  63 }