lib/isblank.c

   1 /* Test whether a character is a blank.
   2
   3    Copyright (C) 2009-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <ctype.h>
  22
  23 int
  24 isblank (int c)
  25 {
  26   /* On all known platforms, in all predefined locales, isblank(c) is likely
  27      equivalent with  (c == ' ' || c == '\t').  Look at the glibc definition
  28      (in glibc/localedata/locales/i18n): The "blank" characters are '\t', ' ',
  29      U+1680, U+180E, U+2000..U+2006, U+2008..U+200A, U+205F, U+3000, and none
  30      except the first two is present in a common 8-bit encoding.  Therefore
  31      the substitute for other platforms is not more complicated than this.  */
  32   return (c == ' ' || c == '\t');
  33 }