I'd be very surprised if a pure-Perl script beat a native utility like cut.

If cutting out of the columns of these large files is a bottleneck, your options include:

• As you mentioned, piping the output of cut to your script;
• Running cut as a pipe from within your script:

  open my $cutter, "-|", 'cut', '-d,', '-f"1-15"', $mongo
    or die "Fork failed: $!\n";
  go_to_town( $_ ) while <$cutter>;
  close $cutter;
  [download]

  See perlipc.
• Write a Perl extension module (XS, Inline::C, Swig) to extract the rows.

I like the second option best.

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.