3 dnl Copyright (C) 2009-2024 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
8 AC_DEFUN([gl_FUNC_ISBLANK],
10 dnl Persuade glibc <ctype.h> to declare isblank().
11 AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
13 AC_REQUIRE([gl_CTYPE_H_DEFAULTS])
14 AC_CHECK_FUNCS_ONCE([isblank])
15 if test $ac_cv_func_isblank = no; then