Hello,

Question about Bash scripting in Ubuntu.

I am struggling here about the following, copying username to a new file and then deleting username in existing file only if older then 30 minutes (plain text file) but don't copy username to new file when same user is found with newer time stamp and delete the oldest time stamp of the corresponding user.

In a process i keep track the users login time in a file, login time is based on:

date +%s%N


The string within the file only is buildup as followed:
(no spaces in username)

date username@domain.com

Now i believe 'While Do' can do this trick, but i can't my way use 'If' in 'While Do'. Maybe another approach or 'While Do' is the approach?