From 4b41e9b7dc4438aec894d034923164e1884ca0c2 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sun, 18 Oct 2009 21:16:44 +0200
Subject: [PATCH] New module 'isblank'.

---
 ChangeLog                        |  8 ++++++++
 doc/posix-functions/isblank.texi |  8 ++++----
 lib/isblank.c                    | 33 +++++++++++++++++++++++++++++++++
 m4/isblank.m4                    | 19 +++++++++++++++++++
 modules/isblank                  | 25 +++++++++++++++++++++++++
 5 files changed, 89 insertions(+), 4 deletions(-)
 create mode 100644 lib/isblank.c
 create mode 100644 m4/isblank.m4
 create mode 100644 modules/isblank

diff --git a/ChangeLog b/ChangeLog
index caeadf26c..3bbcc2a37 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2009-10-18  Bruno Haible  <bruno@clisp.org>
 
+	New module 'isblank'.
+	* lib/isblank.c: New file.
+	* m4/isblank.m4: New file.
+	* modules/isblank: New file.
+	* doc/posix-functions/isblank.texi: Mention the new module.
+
+2009-10-18  Bruno Haible  <bruno@clisp.org>
+
 	New module 'ctype'.
 	* lib/ctype.in.h: New file.
 	* m4/ctype.m4: New file.
diff --git a/doc/posix-functions/isblank.texi b/doc/posix-functions/isblank.texi
index 254779303..12bcd9112 100644
--- a/doc/posix-functions/isblank.texi
+++ b/doc/posix-functions/isblank.texi
@@ -4,15 +4,15 @@
 
 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/isblank.html}
 
-Gnulib module: ---
+Gnulib module: isblank
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on some platforms:
+AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, mingw.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on some platforms:
-AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, mingw.
 @end itemize
diff --git a/lib/isblank.c b/lib/isblank.c
new file mode 100644
index 000000000..e2d5503d1
--- /dev/null
+++ b/lib/isblank.c
@@ -0,0 +1,33 @@
+/* Test whether a character is a blank.
+
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://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');
+}
diff --git a/m4/isblank.m4 b/m4/isblank.m4
new file mode 100644
index 000000000..37f1a75a5
--- /dev/null
+++ b/m4/isblank.m4
@@ -0,0 +1,19 @@
+# isblank.m4 serial 1
+dnl Copyright (C) 2009 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_ISBLANK],
+[
+  dnl Persuade glibc <ctype.h> to declare isblank().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_REQUIRE([gl_CTYPE_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([isblank])
+  if test $ac_cv_func_isblank = no; then
+    HAVE_ISBLANK=0
+    CTYPE_H='ctype.h'
+    AC_LIBOBJ([isblank])
+  fi
+])
diff --git a/modules/isblank b/modules/isblank
new file mode 100644
index 000000000..6dbb371f7
--- /dev/null
+++ b/modules/isblank
@@ -0,0 +1,25 @@
+Description:
+isblank() function: test whether a single-byte character is a blank.
+
+Files:
+lib/isblank.c
+m4/isblank.m4
+
+Depends-on:
+extensions
+ctype
+
+configure.ac:
+gl_FUNC_ISBLANK
+gl_CTYPE_MODULE_INDICATOR([isblank])
+
+Makefile.am:
+
+Include:
+<ctype.h>
+
+License:
+LGPLv2+
+
+Maintainer:
+Bruno Haible
-- 
2.11.0