12 #define _GNU_SOURCE // program_invocation_name, program_invocation_short_name
25 # define GU_SYS_PROGRAM_NAME getexecname ()
26 #elif defined(__APPLE__) || defined(__FreeBSD__)
27 # define GU_SYS_PROGRAM_NAME getprogname ()
28 #elif defined(__linux__)
29 # define GU_SYS_PROGRAM_NAME program_invocation_name