This is NOT used for the Linux version. These are part of the standard C library for Linux and Cygwin. For the Windows version we need to include our own copy. They were copied from Cygwin source: /usr/src/cygwin-1.7.10-1/newlib/libc/string/strsep.c /usr/src/cygwin-1.7.10-1/newlib/libc/string/strtok_r.c