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-rw-r--r--m4/ax_func_snprintf.m482
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diff --git a/m4/ax_func_snprintf.m4 b/m4/ax_func_snprintf.m4
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+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_func_snprintf.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_FUNC_SNPRINTF
+#
+# DESCRIPTION
+#
+# Checks for a fully C99 compliant snprintf, in particular checks whether
+# it does bounds checking and returns the correct string length; does the
+# same check for vsnprintf. If no working snprintf or vsnprintf is found,
+# request a replacement and warn the user about it. Note: the mentioned
+# replacement is freely available and may be used in any project
+# regardless of it's license.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Ruediger Kuhlmann <info@ruediger-kuhlmann.de>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 5
+
+AC_DEFUN([AX_FUNC_SNPRINTF],
+[AC_CHECK_FUNCS(snprintf vsnprintf)
+AC_MSG_CHECKING(for working snprintf)
+AC_CACHE_VAL(ac_cv_have_working_snprintf,
+[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h>
+
+int main(void)
+{
+ char bufs[5] = { 'x', 'x', 'x', '\0', '\0' };
+ char bufd[5] = { 'x', 'x', 'x', '\0', '\0' };
+ int i;
+ i = snprintf (bufs, 2, "%s", "111");
+ if (strcmp (bufs, "1")) exit (1);
+ if (i != 3) exit (1);
+ i = snprintf (bufd, 2, "%d", 111);
+ if (strcmp (bufd, "1")) exit (1);
+ if (i != 3) exit (1);
+ exit(0);
+}]])],[ac_cv_have_working_snprintf=yes],[ac_cv_have_working_snprintf=no],[ac_cv_have_working_snprintf=cross])])
+AC_MSG_RESULT([$ac_cv_have_working_snprintf])
+AC_MSG_CHECKING(for working vsnprintf)
+AC_CACHE_VAL(ac_cv_have_working_vsnprintf,
+[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h>
+#include <stdarg.h>
+
+int my_vsnprintf (char *buf, const char *tmpl, ...)
+{
+ int i;
+ va_list args;
+ va_start (args, tmpl);
+ i = vsnprintf (buf, 2, tmpl, args);
+ va_end (args);
+ return i;
+}
+
+int main(void)
+{
+ char bufs[5] = { 'x', 'x', 'x', '\0', '\0' };
+ char bufd[5] = { 'x', 'x', 'x', '\0', '\0' };
+ int i;
+ i = my_vsnprintf (bufs, "%s", "111");
+ if (strcmp (bufs, "1")) exit (1);
+ if (i != 3) exit (1);
+ i = my_vsnprintf (bufd, "%d", 111);
+ if (strcmp (bufd, "1")) exit (1);
+ if (i != 3) exit (1);
+ exit(0);
+}]])],[ac_cv_have_working_vsnprintf=yes],[ac_cv_have_working_vsnprintf=no],[ac_cv_have_working_vsnprintf=cross])])
+AC_MSG_RESULT([$ac_cv_have_working_vsnprintf])
+if test x$ac_cv_have_working_snprintf$ac_cv_have_working_vsnprintf != "xyesyes"; then
+ AC_LIBOBJ(snprintf)
+ AC_MSG_WARN([Replacing missing/broken (v)snprintf() with sudo's version.])
+ AC_DEFINE(PREFER_PORTABLE_SNPRINTF, 1, [Enable replacement (v)snprintf if system (v)snprintf is broken.])
+fi])