The effective uid of this process. For example:
$< = $>; # set real to effective uid ($<,$>) = ($>,$<); # swap real and effective uids
You can change both the effective uid and the real uid at the same time by using
POSIX::setuid(). Changes to
$> require a check to
$! to detect any possible errors after an attempted change.
$> can be swapped only on machines supporting
Mnemonic: it's the uid you went to, if you're running setuid.