1 dnl AC_FUNC_SCANF_CAN_MALLOC macro 2 dnl 3 dnl (c) Finn Thain 2006 4 dnl Copying and distribution of this file, with or without modification, 5 dnl are permitted in any medium without royalty provided the copyright 6 dnl notice and this notice are preserved. 7 8 # AC_FUNC_SCANF_CAN_MALLOC() 9 # -------------------------------------- 10 AC_DEFUN([AC_FUNC_SCANF_CAN_MALLOC], 11 [ AC_CHECK_HEADERS([stdlib.h]) 12 AC_CACHE_CHECK([whether scanf can malloc], [ac_scanf_can_malloc], 13 [ AC_RUN_IFELSE( 14 [ AC_LANG_PROGRAM( 15 [ 16 #include <stdio.h> 17 #if STDC_HEADERS || HAVE_STDLIB_H 18 #include <stdlib.h> 19 #endif 20 ], [ 21 union { float f; char *p; } u; 22 char *p; 23 u.f = 0; 24 char *scan_this = "56789"; 25 int matched = sscanf(scan_this, "%as", &u); 26 if(matched < 1) return 1; /* shouldn't happens */ 27 if(u.f == (float)56789) return 2; 28 29 p = u.p; 30 while(*scan_this && *p == *scan_this) { 31 ++p; 32 ++scan_this; 33 }; 34 free(u.p); 35 if(*scan_this == 0) return 0; 36 return 3; 37 ]) 38 ], 39 [ac_scanf_can_malloc=yes], 40 [ac_scanf_can_malloc=no], 41 [ 42 case $host_alias in 43 *-*-linux* ) ac_scanf_can_malloc=yes ;; 44 *-*-solaris* ) ac_scanf_can_malloc=no ;; 45 *-*-darwin* ) ac_scanf_can_malloc=no ;; 46 * ) ac_scanf_can_malloc=no ;; 47 esac 48 ]) 49 ]) 50 if test x$ac_scanf_can_malloc = "xyes"; then 51 AC_DEFINE([SCANF_CAN_MALLOC], 1, [Define to 1 if the scanf %a conversion format mallocs a buffer. Undefine if %a format denotes a float.]) 52 fi 53 ]) 54
