Index: string.h =================================================================== RCS file: /cvsroot/src/include/string.h,v retrieving revision 1.51 diff -u -r1.51 string.h --- string.h 12 Oct 2016 20:01:22 -0000 1.51 +++ string.h 20 Feb 2018 02:32:08 -0000 @@ -74,7 +74,8 @@ #endif /* _POSIX_C_SOURCE >= 199506 || XOPEN_SOURCE >= 500 || ... */ size_t strxfrm(char * __restrict, const char * __restrict, size_t); -#if defined(_XOPEN_SOURCE) || defined(_NETBSD_SOURCE) +#if (_POSIX_C_SOURCE - 0 >= 200112L) || defined(_XOPEN_SOURCE) || \ + defined(_NETBSD_SOURCE) void *memccpy(void *, const void *, int, size_t); char *strdup(const char *); #endif