Hi lax,

Take a look at substr:

#!/usr/bin/perl
use strict;
use warnings;

my $string="012345678901234567890"
print substr($string,0,16);
[download]

My test string is 20 characters long, so I have set the length of the substr function to 16. you can easily change that to 160 for your line.

Update: Oops I forgot that you may not know how to open a file:

#!/usr/bin/perl
use strict;
use warnings;

open(FILE,"yourfilenamehere.txt") or die "Could not open file $!\n"; #
+ open yourfilenamehere.txt for reading
while(<FILE>){     #read yourfilenamehere.txt a line at a time
    chomp;         
    print "\n" . substr($_,0,160);    #as described above, except prin
+t first 160 characters only
}
close FILE    #close filehandle
[download]

You will need to change the filename, obviously. You may wish to check out the Tutorials section of this site.

Update: Added comments to second code posting.

Hope this helps.

Martin