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Full Discussion: Honey, I broke awk! (duplicate line removal in 30M line 3.7GB csv file)
Top Forums Shell Programming and Scripting Honey, I broke awk! (duplicate line removal in 30M line 3.7GB csv file) Post 302894688 by Chubler_XL on Wednesday 26th of March 2014 06:07:33 PM
Old 03-26-2014
Do you really need to compare the whole line for uniqueness?

You should get a big reduction in memory usage by only checking the first 100 chars with:

Code:
awk '!(substr($0,1,100) in a) { a[substr($0,1,100)]; print }'

 

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LEARN ABOUT DEBIAN

perlio::via::symlink

symlink(3pm)						User Contributed Perl Documentation					      symlink(3pm)

NAME

       PerlIO::via::symlink - PerlIO layers for create symlinks

SYNOPSIS

	open $fh, '>:via(symlink)', $fname;
	print $fh "link foobar";
	close $fh;

DESCRIPTION

       The PerlIO layer "symlink" allows you to create a symbolic link by writing to the file handle.

       You need to write C"link $name" to the file handle. If the format does not match, "close" will fail with EINVAL.

TEST COVERAGE

	----------------------------------- ------ ------ ------ ------ ------ ------
	File				      stmt branch   cond    sub   time	total
	----------------------------------- ------ ------ ------ ------ ------ ------
	blib/lib/PerlIO/via/symlink.pm	     100.0  100.0    n/a  100.0  100.0	100.0
	Total				     100.0  100.0    n/a  100.0  100.0	100.0
	----------------------------------- ------ ------ ------ ------ ------ ------

AUTHORS

       Chia-liang Kao <clkao@clkao.org>

COPYRIGHT

       Copyright 2004-2005 by Chia-liang Kao <clkao@clkao.org>.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

       See <http://www.perl.com/perl/misc/Artistic.html>

perl v5.8.8							    2005-04-21							      symlink(3pm)
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