Untested, but no glaring mistakes obvious to me. If you see any, yell at me. Update: turns out there are rather serious ones. Do not use this code. Left here for posterity. 
#!/usr/bin/perl -w
use strict;
#deletes first numbytes of a file

#### DO NOT USE #####

#use constant BLOCKSIZE => 128*1024;
#
#die "Usage: $0 numbytes file [file ...]\n" unless @ARGV > 2;
#
#my $trunc_bytes = shift @ARGV;
#my $files_done = 0;
#
#for(@ARGV) {
#    open(my $fh, "+<", $_) or (warn "Couldn't open $_: $!\n", next);
#    if(-s $fh > $trunc_bytes ) {
#        seek $fh, 0, $trunc_bytes;
#        while(my $bytes_read = read $fh, my $buffer, BLOCKSIZE) {
#            seek $fh, 1, -$bytes_read -$trunc_bytes;
#            print $fh $buffer;
#            seek $fh, 1, $trunc_bytes;
#        }
#    }
#    truncate $fh, tell $fh;
#    close $fh;
#    $files_done++;
#}
#
#exit $files_done == 0;

#### DO NOT USE #####

[download]
This should run at least a bit faster than your version since it doesn't concern itself with end-of-lines at all. Depending on how smart Tie::File is, it may be a whole lot faster - though as far as I know Dominus put some effort into making it clever. Still, you need no module for this of all tasks..

Makeshifts last the longest.

In reply to Re: head truncate by Aristotle
in thread head truncate by zentara

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