getlogin

See the current Perl documentation for getlogin.

Here is our local, out-dated (pre-5.6) version:

getlogin - return who logged in at this tty

getlogin

Implements the C library function of the same name, which on most systems returns the current login from /etc/utmp, if any. If null, use getpwuid().

    $login = getlogin || getpwuid($<) || "Kilroy";

Do not consider getlogin() for authentication: it is not as secure as getpwuid().