perl -ne "$. ==1 and print;" filename.txt
##</code><code>##

perl -e "print scalar <>;" filename.txt
##</code><code>##

perl -ne "print and last;" filename.txt
##</code><code>##

perl -ne "last; END{print}" filename.txt
##</code><code>##

perl -ne "die $_;" filename.txt
##</code><code>##

perl -pe "$. > 1 and last;" filename.txt