for i in 1 2 3 4 5; do perl -e'print "$_\n" foreach 1..$ARGV[0]' $i > $i;done

##</code><code>##

perl -ne'printf "File: $ARGV \$.: %2d real line: $_",$. if $. & 1' 1 2 3 4 5

##</code><code>##

File: 1 $.:  1 : real line: 1
File: 2 $.:  3 : real line: 2
File: 3 $.:  5 : real line: 2
File: 4 $.:  7 : real line: 1
File: 4 $.:  9 : real line: 3
File: 5 $.: 11 : real line: 1
File: 5 $.: 13 : real line: 3
File: 5 $.: 15 : real line: 5