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Top Forums Shell Programming and Scripting Diamond operator in Until Statement (perl) Post 302267427 by erichpowell on Friday 12th of December 2008 10:01:45 AM
Old 12-12-2008
radoulov: Thanks for the reply. I can tell you spent some time on that.
Unfortunately, I'm pretty new to perl and I've never used the command line option (which I think that is), so it might take me a while to decipher what's going on.

If you don't mind, I have a couple questions to start with:

1) How does this line of code work:
Code:
/^ID   (\w+)/ and $Gene = $1;

I think it's saying: if the regEx finds a match, assign what's in the parenthesis to $Gene.

If that's it, it's very similar to what I was doing here:
Code:
if (/^(ID   )([A-Za-z0-9_]*)/) {
            print "GENE: $2\n";
        }

I just don't understand how you are able to do make a conditional statement without an 'if ' construct. Can you please elaborate on how this works?

2)My second question is about this line:
Code:
if (/^CC   -!- FUNCTION:/../CC   -!- SUBCELLULAR/) {

It seems like this regEx contains four slashes. I've never seen one like that. I assume this is used to get the text in between FUNCTION and SUBCELLULAR, but again, I just don't understand how it works.

Thanks again for your reply, and thanks in advance for your help with these questions. I know that I'm going to learn a lot from this exercise and I can tell that your approach is very efficient.
 

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IO::Async::Protocol::LineStream(3pm)			User Contributed Perl Documentation		      IO::Async::Protocol::LineStream(3pm)

NAME
"IO::Async::Protocol::LineStream" - stream-based protocols using lines of text SYNOPSIS
Most likely this class will be subclassed to implement a particular network protocol. package Net::Async::HelloWorld; use strict; use warnings; use base qw( IO::Async::Protocol::LineStream ); sub on_read_line { my $self = shift; my ( $line ) = @_; if( $line =~ m/^HELLO (.*)/ ) { my $name = $1; $self->invoke_event( on_hello => $name ); } } sub send_hello { my $self = shift; my ( $name ) = @_; $self->write_line( "HELLO $name" ); } This small example elides such details as error handling, which a real protocol implementation would be likely to contain. DESCRIPTION
EVENTS
The following events are invoked, either using subclass methods or CODE references in parameters: on_read_line $line Invoked when a new complete line of input is received. PARAMETERS
The following named parameters may be passed to "new" or "configure": on_read_line => CODE CODE reference for the "on_read_line" event. METHODS
$lineprotocol->write_line( $text ) Writes a line of text to the transport stream. The text will have the end-of-line marker appended to it; $text should not end with it. AUTHOR
Paul Evans <leonerd@leonerd.org.uk> perl v5.14.2 2012-10-24 IO::Async::Protocol::LineStream(3pm)
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