merge --version (return code: 0)
merge (GNU RCS) 5.9.4 Copyright (C) 2010-2015 Thien-Thi Nguyen Copyright (C) 1990-1995 Paul Eggert Copyright (C) 1982,1988,1989 Walter F. Tichy, Purdue CS License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
merge --help (return code: 0)
Usage: merge [options] receiving-sibling parent other-sibling Three-way file merge. Options: -A Use `diff3 -A' style. -E Use `diff3 -E' style (default). -e Use `diff3 -e' style. -p Write to stdout instead of overwriting RECEIVING-SIBLING. -q Quiet mode; suppress conflict warnings. -LLABEL (up to three times) Specify the conflict labels for RECEIVING-SIBLING, PARENT and OTHER-SIBLING, respectively. -V Obsolete; do not use. Report bugs to: <email@example.com> RCS home page: <http://www.gnu.org/software/rcs/> General help using GNU software: <http://www.gnu.org/gethelp/>