1# stpncpy.m4 serial 4 2dnl Copyright (C) 2002-2003, 2005-2006 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7AC_DEFUN([gl_FUNC_STPNCPY], 8[ 9 dnl Persuade glibc <string.h> to declare stpncpy(). 10 AC_REQUIRE([AC_GNU_SOURCE]) 11 12 dnl Both glibc and AIX (4.3.3, 5.1) have an stpncpy() function 13 dnl declared in <string.h>. Its side effects are the same as those 14 dnl of strncpy(): 15 dnl stpncpy (dest, src, n) 16 dnl overwrites dest[0..n-1], min(strlen(src),n) bytes coming from src, 17 dnl and the remaining bytes being NULs. However, the return value is 18 dnl in glibc: dest + min(strlen(src),n) 19 dnl in AIX: dest + max(0,n-1) 20 dnl Only the glibc return value is useful in practice. 21 22 AC_CACHE_CHECK([for working stpncpy], gl_cv_func_stpncpy, [ 23 AC_TRY_RUN([ 24#include <stdlib.h> 25#include <string.h> /* for strcpy */ 26/* The stpncpy prototype is missing in <string.h> on AIX 4. */ 27extern char *stpncpy (char *dest, const char *src, size_t n); 28int main () { 29 const char *src = "Hello"; 30 char dest[10]; 31 /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+1 here. */ 32 strcpy (dest, "\377\377\377\377\377\377"); 33 if (stpncpy (dest, src, 2) != dest + 2) exit(1); 34 /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+4 here. */ 35 strcpy (dest, "\377\377\377\377\377\377"); 36 if (stpncpy (dest, src, 5) != dest + 5) exit(1); 37 /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+6 here. */ 38 strcpy (dest, "\377\377\377\377\377\377"); 39 if (stpncpy (dest, src, 7) != dest + 5) exit(1); 40 exit(0); 41} 42], gl_cv_func_stpncpy=yes, gl_cv_func_stpncpy=no, 43 [AC_EGREP_CPP([Thanks for using GNU], [ 44#include <features.h> 45#ifdef __GNU_LIBRARY__ 46 Thanks for using GNU 47#endif 48], gl_cv_func_stpncpy=yes, gl_cv_func_stpncpy=no)])]) 49 50 if test $gl_cv_func_stpncpy = yes; then 51 AC_DEFINE(HAVE_STPNCPY, 1, 52 [Define if you have the stpncpy() function and it works.]) 53 else 54 AC_LIBOBJ([stpncpy]) 55 gl_PREREQ_STPNCPY 56 fi 57]) 58 59# Prerequisites of lib/stpncpy.c. 60AC_DEFUN([gl_PREREQ_STPNCPY], [ 61 : 62]) 63 64