--- sort.c.orig 2012-07-04 20:25:12.000000000 +0400 +++ sort.c 2014-01-21 07:18:36.832891740 +0400 @@ -146,7 +146,7 @@ #define NUMBER_OF_MUTUALLY_EXCLUSIVE_FLAGS 6 static const char mutually_exclusive_flags[NUMBER_OF_MUTUALLY_EXCLUSIVE_FLAGS] = { 'M', 'n', 'g', 'R', 'h', 'V' }; -struct option long_options[] = { +static struct option long_options[] = { { "batch-size", required_argument, NULL, BS_OPT }, { "buffer-size", required_argument, NULL, 'S' }, { "check", optional_argument, NULL, 'c' },