1 files changed, 33 insertions, 0 deletions
diff --git a/lib/isblank.c b/lib/isblank.c
new file mode 100644
index 0000000..e354559
--- /dev/null
+++ b/lib/isblank.c
@@ -0,0 +1,33 @@
+/* Test whether a character is a blank.
+
+   Copyright (C) 2009-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <ctype.h>
+
+int
+isblank (int c)
+{
+  /* On all known platforms, in all predefined locales, isblank(c) is likely
+     equivalent with  (c == ' ' || c == '\t').  Look at the glibc definition
+     (in glibc/localedata/locales/i18n): The "blank" characters are '\t', ' ',
+     U+1680, U+180E, U+2000..U+2006, U+2008..U+200A, U+205F, U+3000, and none
+     except the first two is present in a common 8-bit encoding.  Therefore
+     the substitute for other platforms is not more complicated than this.  */
+  return (c == ' ' || c == '\t');
+}