use strict; use warnings; addStuffToTopOfFile( "New Stuff!\n", 'File.txt' ); sub addStuffToTopOfFile { my ( $stuff, $file ) = @_; local @ARGV; local $^I = '.bak'; push @ARGV, $file; while (<>) { print $stuff if $. == 1; print; } unlink "$file.bak"; } #### Line 1 Line 2 Line 3 Line 4 #### New Stuff! Line 1 Line 2 Line 3 Line 4