RE: Count the number of lines in a file without actually iteratin g through the file

From: Rob Hanson (rhanson_at_aptegrity.com)
Date: 02/26/04 

To: 'Jason Normandin' <jason_normandin@charter.net>, Perl Beginners	 <beginners@perl.org>
Date: Wed, 25 Feb 2004 19:25:53 -0500

> Is there a way to determine the number of lines
> in a file without actually iterating through the
> file and incrementing a file?

No.

> I found the following on perlmonks.org, it works
> great but this is command line syntax

When you deparse that command (see below), you can see that all it does is
read each line of the file and set $_ to the line number (*.). After
reading in each line it then prints the result. So there is no silver
bullet.

$ perl -MO=Deparse -lpe '}{*_=*.}{' file

LINE: while (defined($_ = <ARGV>)) {
    chomp $_;
}
{
    *_ = *.;
}
{
    ();
}
continue {
    die "-p destination: $!\n" unless print $_;
}

-----Original Message-----
From: Jason Normandin [mailto:jason_normandin@charter.net]
Sent: Wednesday, February 25, 2004 6:56 PM
To: Perl Beginners
Subject: Count the number of lines in a file without actually iterating
through the file

Hi List.

 

Is there a way to determine the number of lines in a file without actually
iterating through the file and incrementing a file?

 

I found the following on perlmonks.org, it works great but this is command
line syntax

:

perl -lpe '}{*_=*.}{' file

 

How could I integrate this into a script without invoking another instance
of Perl?

 

Thanks !

~Jason

------------------------------------

 

 "If, after the first twenty minutes, you don't know who the sucker at the
table is, it's you."

 

------------------------------------

 

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