You can use s/// to remove everything after the 1st underscore (inclusive): 
use warnings;
use strict;

my $this_server = 'wppwd01a0099_NET_basp_virtual_adapter';
$this_server =~ s/_.*//;
print "$this_server\n";

__END__

wppwd01a0099

[download]

In reply to Re: minimal match regular expression by toolic
in thread minimal match regulara expression by fionbarr

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