One way to do it is to use Tie::File to treat your file as an array, then just prepend a new first line using unshift: 
use strict;
use warnings;

use Tie::File;
tie my @array, 'Tie::File', 'file.txt' or die $!;
unshift @array, 'new first line';
untie @array;

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In reply to Re: Writing in files by toolic
in thread Writing in files by nicholaspr

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