Fixed a few things: 
#!/usr/intel/bin/perl
use strict;
use warnings;
my @testlist = qw(ctahci cptcsa0 ctsata:25:seed cptcsa1:50:seed ctsata
+_1:25:seed);
my @removelist =qw(cptcsa0 ctsata cptcsa1);
my $outfile = "./new.list";

my %removehash=map{$_=>1} @removelist;

my @newlist=grep !defined( $removehash{ (m/(\w+)/)[0] }), @testlist;

# creating new list
open (my $OUTFILE, ">",$outfile) or die "Cannot open $outfile for writ
+ing:$!\n";

print $OUTFILE "$_\n" foreach (@newlist);

[download]
---Output:---
ctahci
ctsata_1:25:seed

Adjust the regular expression to suite your requirements.

             I hope life isn't a big joke, because I don't get it.
                   -SNL

In reply to Re: Comparing 2 arrays but ignoring certain patterns by NetWallah
in thread Comparing 2 arrays but ignoring certain patterns by hongping

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