Evaluates EXPR and exits immediately with that value. Example:
my $ans = <STDIN>;
exit 0 if $ans =~ /^[Xx]/;See also die. If EXPR is omitted, exits with 0 status. The only universally recognized values for EXPR are 0 for success and 1 for error; other values are subject to interpretation depending on the environment in which the Perl program is running. For example, exiting 69 (EX_UNAVAILABLE) from a sendmail incoming-mail filter will cause the mailer to return the item undelivered, but that's not true everywhere.
Don't use exit to abort a subroutine if there's any chance that someone might want to trap whatever error happened. Use die instead, which can be trapped by an eval.
The exit function does not always exit immediately. It calls any defined END routines first, but these END routines may not themselves abort the exit. Likewise any object destructors that need to be called are called before the real exit. END routines and destructors can change the exit status by modifying $?. If this is a problem, you can call POSIX::_exit($status) to avoid END and destructor processing. See perlmod for details.
Portability issues: "exit" in perlport.