1 files changed, 48 insertions, 0 deletions

diff --git a/gl/m4/strndup.m4 b/gl/m4/strndup.m4
new file mode 100644
index 00000000..dd5780b6
--- /dev/null
+++ b/gl/m4/strndup.m4
@@ -0,0 +1,48 @@
+# strndup.m4 serial 11
+dnl Copyright (C) 2002-2003, 2005-2006 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_STRNDUP],
+[
+  dnl Persuade glibc <string.h> to declare strndup().
+  AC_REQUIRE([AC_GNU_SOURCE])
+
+  AC_CHECK_DECLS_ONCE([strndup])
+
+  # AIX 4.3.3, AIX 5.1 have a function that fails to add the terminating '\0'.
+  AC_CACHE_CHECK([for working strndup], gl_cv_func_strndup,
+    [AC_RUN_IFELSE([
+       AC_LANG_PROGRAM([#include <string.h>
+                        #include <stdlib.h>], [[
+#ifndef HAVE_DECL_STRNDUP
+  extern char *strndup (const char *, size_t);
+#endif
+  char *s;
+  s = strndup ("some longer string", 15);
+  free (s);
+  s = strndup ("shorter string", 13);
+  return s[13] != '\0';]])],
+       [gl_cv_func_strndup=yes],
+       [gl_cv_func_strndup=no],
+       [AC_CHECK_FUNC([strndup],
+          [AC_EGREP_CPP([too risky], [
+#ifdef _AIX
+               too risky
+#endif
+             ],
+             [gl_cv_func_strndup=no],
+             [gl_cv_func_strndup=yes])],
+          [gl_cv_func_strndup=no])])])
+  if test $gl_cv_func_strndup = yes; then
+    AC_DEFINE([HAVE_STRNDUP], 1,
+      [Define if you have the strndup() function and it works.])
+  else
+    AC_LIBOBJ([strndup])
+    gl_PREREQ_STRNDUP
+  fi
+])
+
+# Prerequisites of lib/strndup.c.
+AC_DEFUN([gl_PREREQ_STRNDUP], [:])