#cat a.txt
a file line 1
a file line 2
a file line 3

#cat b.txt
b file line 1
b file line 2
b file line 3

##</code><code>##

#perl -ne "print if 1..2" a.txt b.txt
a file line 1
a file line 2

##</code><code>##

#perl -ne "print if 1..2; close ARGV if eof" a.txt b.txt
a file line 1
a file line 2
b file line 1
b file line 2