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Is there a program that displays the login message formatted like this:

Last login: Wed Oct 24 16:40:33 2012

Or do I have to write my own program/script? I was wondering if there is a command the Linux kernel (or whoever) runs to do that.

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Check # man last (shows details of last logged in users). # echo last -n 2 root >> /etc/profile would show last 2 logged-in session for user 'root'. Is it that you was looking for? – Mayur Pipaliya Oct 27 '12 at 20:24
No. I would like it to be in the format mentioned above. – BenjiWiebe Oct 27 '12 at 20:25

2 Answers

up vote 2 down vote

The kernel does not track login information. You can configure PAM (/etc/pam.d) to call the pam_lastlog.so module, which shows exactly what you want:

session optional pam_lastlog.so noterm nohost

Or a bit more verbose:

session optional pam_lastlog.so

Or one that also prints failed logins:

session optional pam_lastlog.so showfailed

On Fedora, it might go to /etc/pam.d/system-login or /etc/pam.d/gdm-password, I'm not sure.

The information is stored in /var/log/wtmp and /var/log/lastlog.

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Yes it has been showing it like that, but I have a custom MOTD script that scrolls it up out of sight. So I need to be able to output it from the end of my script. Good answer though. I just didn't explain my problem well enough. – BenjiWiebe Oct 27 '12 at 20:17
1  
@BenjiWiebe: Change the motd script to be displayed by pam_motd.so instead? If it must be different for every user, re-generate it with pam_exec.so. Put them above pam_lastlog.so in the "session" section. – grawity Oct 27 '12 at 20:27
Hmmmm. Not sure what you mean/how to do it. – BenjiWiebe Oct 27 '12 at 20:29
@BenjiWiebe: Why is the motd displayed by a script? Does it change with time, or does it change for different users? – grawity Oct 27 '12 at 20:30
It is a colored, somewhat animated, script that changes per user and also changes as time goes by. – BenjiWiebe Oct 27 '12 at 20:32
up vote 0 down vote accepted

I wrote some code to do it for me:

LINE=`lastlog -u $USER | head -n2 | tail -n1`;
WORDS=`echo "$LINE" | wc -w`;
if [ "x$WORDS" = "x9" ]; then
  echo "$LINE" | awk '{ printf "Last login: %s %s  %s %s %s from %s\n", $4, $5, $6, $7, $9, $3 }';
else
  echo "Unsupported case.";
fi;

It doesn't work for non-remote logins, but I am running the code on a headless server, so 99.9% of the logins will be remote logins; the other 0.1% will be when I "attach a head" to fix ssh issues or similar.

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