Do nothing, returning a non-zero (false) exit status
SYNTAX false DESCRIPTION `false' does nothing except return an exit status of 1, meaning "failure". It can be used as a place holder in shell scripts where an unsuccessful command is needed. `false' ignores _all_ command line arguments, even `--help' and `--version', since to do otherwise would change expected behavior that some programmers may be relying on. This version of `false' is implemented as a C program, and is thus more secure and faster than a shell script implementation, and may safely be used as a dummy shell for the purpose of disabling accounts.
true - Do nothing, successfully
yes - Print a string until interrupted