'''lastlog''' is a program available on most Linux distributions. It formats and prints the contents of the last login log file, <code>/var/log/lastlog</code> (which is a usually a very sparse file), including the login name, port, and last login date and time. It is similar in functionality to the BSD program '''last''', also included in Linux distributions; however, '''last''' parses a different binary database file (<code>/var/log/wtmp</code> and <code>/var/log/btmp</code>).
The file is updated by the <code>pam_lastlog.so</code> Pluggable Authentication Module.<ref>{{cite web |title=linux-pam source code |url=https://github.com/linux-pam/linux-pam/blob/bc856cd9b9b461e8e2a537f4d9db87d315f5fe7b/modules/pam_lastlog/pam_lastlog.c#L6-L8 |website=Github |access-date=2025-04-21 |ref=src}}</ref> The module has been deprecated since 2023, and is announced to be removed in future releases of the pam-linux framework, due to the data structures inherently being affected by the Year 2038 problem.<ref>{{cite web |title=linux-pam NEWS document |url=https://github.com/linux-pam/linux-pam/blob/bc856cd9b9b461e8e2a537f4d9db87d315f5fe7b/NEWS#L76-L78 |website=github |access-date=2025-04-21}}</ref>
== Usage == Lastlog prints its output in column format with login-name, port, and last-login-time of each and every user on the system mentioned in that order. The users are sorted by default according to the order in <code>/etc/passwd</code> However, it can also be used to modify the records kept in <code>/var/log/lastlog</code>.<syntaxhighlight lang="console"> $ lastlog Username Port From Latest root **Never logged in** user tty3 Sun Jan 14 16:29:24 +0130 2019 </syntaxhighlight>
== References == {{Reflist}}
== External links == * {{man|8|lastlog|die.net}}
{{Unix commands}}
Category:Unix user management and support-related utilities