Function ProgramInvocationShortName

libs/gflags/src/gflags.cc:1503–1509

  return GetArgv0();
}
const char* ProgramInvocationShortName() {        // like the GNU libc fn
  const char* slash = strrchr(argv0, '/');
#ifdef OS_WINDOWS
  if (!slash)  slash = strrchr(argv0, '\\');
#endif
  return slash ? slash + 1 : argv0;
}

void SetUsageMessage(const string& usage) {
  if (program_usage != NULL)