1# =========================================================================== 2# http://www.gnu.org/software/autoconf-archive/ax_func_snprintf.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_FUNC_SNPRINTF 8# 9# DESCRIPTION 10# 11# Checks for a fully C99 compliant snprintf, in particular checks whether 12# it does bounds checking and returns the correct string length; does the 13# same check for vsnprintf. If no working snprintf or vsnprintf is found, 14# request a replacement and warn the user about it. Note: the mentioned 15# replacement is freely available and may be used in any project 16# regardless of it's license. 17# 18# LICENSE 19# 20# Copyright (c) 2008 Ruediger Kuhlmann <info@ruediger-kuhlmann.de> 21# 22# Copying and distribution of this file, with or without modification, are 23# permitted in any medium without royalty provided the copyright notice 24# and this notice are preserved. This file is offered as-is, without any 25# warranty. 26 27#serial 5 28 29AC_DEFUN([AX_FUNC_SNPRINTF], 30[AC_CHECK_FUNCS(snprintf vsnprintf) 31AC_MSG_CHECKING(for working snprintf) 32AC_CACHE_VAL(ac_cv_have_working_snprintf, 33[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h> 34#include <string.h> 35 36int main(void) 37{ 38 char bufs[5] = { 'x', 'x', 'x', '\0', '\0' }; 39 char bufd[5] = { 'x', 'x', 'x', '\0', '\0' }; 40 int i; 41 i = snprintf (bufs, 2, "%s", "111"); 42 if (strcmp (bufs, "1")) return (1); 43 if (i != 3) return (1); 44 i = snprintf (bufd, 2, "%d", 111); 45 if (strcmp (bufd, "1")) return (1); 46 if (i != 3) return (1); 47 return(0); 48}]])],[ac_cv_have_working_snprintf=yes],[ac_cv_have_working_snprintf=no],[ac_cv_have_working_snprintf=cross])]) 49AC_MSG_RESULT([$ac_cv_have_working_snprintf]) 50AC_MSG_CHECKING(for working vsnprintf) 51AC_CACHE_VAL(ac_cv_have_working_vsnprintf, 52[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h> 53#include <stdarg.h> 54#include <string.h> 55 56int my_vsnprintf (char *buf, const char *tmpl, ...) 57{ 58 int i; 59 va_list args; 60 va_start (args, tmpl); 61 i = vsnprintf (buf, 2, tmpl, args); 62 va_end (args); 63 return i; 64} 65 66int main(void) 67{ 68 char bufs[5] = { 'x', 'x', 'x', '\0', '\0' }; 69 char bufd[5] = { 'x', 'x', 'x', '\0', '\0' }; 70 int i; 71 i = my_vsnprintf (bufs, "%s", "111"); 72 if (strcmp (bufs, "1")) return (1); 73 if (i != 3) return (1); 74 i = my_vsnprintf (bufd, "%d", 111); 75 if (strcmp (bufd, "1")) return (1); 76 if (i != 3) return (1); 77 return(0); 78}]])],[ac_cv_have_working_vsnprintf=yes],[ac_cv_have_working_vsnprintf=no],[ac_cv_have_working_vsnprintf=cross])]) 79AC_MSG_RESULT([$ac_cv_have_working_vsnprintf]) 80if test x$ac_cv_have_working_snprintf$ac_cv_have_working_vsnprintf != "xyesyes"; then 81 AC_LIBOBJ(snprintf) 82 AC_MSG_WARN([Replacing missing/broken (v)snprintf() with sudo's version.]) 83 AC_DEFINE(PREFER_PORTABLE_SNPRINTF, 1, [Enable replacement (v)snprintf if system (v)snprintf is broken.]) 84fi]) 85