You can set the input record separator ($/) to ) and input your data a block at a time. Resetting the separator inside the chunk reading loop reuses the same trick to parse the lines. Consider:

use strict;
use warnings;

my $data = <<DATA;
(CSW - Q1)
OMIPMS55:NTTCSWQ1:MQSI.3PL846
OMIPMS55:NTTCSWQ1:MQSI.STATUS
OMIPMS55:NTTCSWQ1:MQSI.3PLXDOCK.STATE
(CSW - Q2)
OMIPMS55:NTTCSWQ2:MQSI.3PL846
OMIPMS55:NTTCSWQ2:MQSI.3PL944
(CSW - Q3)
OMIPMS55:NTTCSWQ3:MQSI.3PL846
DATA

local $/ = ')';
open IN, '<', \$data;
while (defined (my $chunk = <IN>)) {
    chomp $chunk;

    local $/ = "\n";
    open LINES, '<', \$chunk;
    my @lines = <LINES>;
    close LINES;
    pop @lines if $lines[-1] =~ '\(';
    print @lines;
}
close IN;

[download]

Prints:

OMIPMS55:NTTCSWQ1:MQSI.3PL846
OMIPMS55:NTTCSWQ1:MQSI.STATUS
OMIPMS55:NTTCSWQ1:MQSI.3PLXDOCK.STATE

OMIPMS55:NTTCSWQ2:MQSI.3PL846
OMIPMS55:NTTCSWQ2:MQSI.3PL944

OMIPMS55:NTTCSWQ3:MQSI.3PL846

[download]
Perl is environmentally friendly - it saves trees

In reply to Re: matching some lines by GrandFather
in thread matching some lines by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.