[txutxu]

After read the article... all the reasoning... I think I could go with this for such reasons exposed:

    perl -ne 'last if $. > 500; /mail/ && print' access.log

When you're done with the part after the &&, remove the 'last if $. > 500'

For me, the most useful use of (gnu) cat, is cat -A weird.file

It saves my day or solves weird issues (X-files) with files generated by (not so) junior sysadmins, copy/pastes, end of lines, invisible diffs, etc... many times each year.

[0xbadcafebee]

But then it's not modular! I need this one-liner to be more complicated because I read a classic paper recently.