PERL Beginners - Quick regex question

Author

Quick regex question

Chris

2006-01-24, 6:56 pm

Hi list,

I am not sure if there is a proper name for this but was having some
difficulty searching for it.

Basically I have data in a file that is between two different
characters, for example:

# data data
data
data data data *
# more dataaa
moreeee *

Basically I want to slurp that file in, then search for # and extract
all the data up to the * and print it, new line, next set of data.

Any pointers would be great.

Thanks!

Chas Owens

2006-01-24, 6:56 pm

On 1/24/06, Chris <chrisp3623@comcast.net> wrote:
> Hi list,
>
> I am not sure if there is a proper name for this but was having some
> difficulty searching for it.
>
> Basically I have data in a file that is between two different
> characters, for example:
>
> # data data
> data
> data data data *
> # more dataaa
> moreeee *
>
> Basically I want to slurp that file in, then search for # and extract
> all the data up to the * and print it, new line, next set of data.
>
> Any pointers would be great.
>
> Thanks!
>

I think what you are looking for is the $/ variable. Whatever you set
it to is what the daimond operator uses to delimit records (by default
it is \n). See "perldoc perlvar" for more info.

John Doe

2006-01-24, 6:56 pm

Chris am Dienstag, 24. Januar 2006 22.35:
> Hi list,
>
> I am not sure if there is a proper name for this but was having some
> difficulty searching for it.
>
> Basically I have data in a file that is between two different
> characters, for example:
>
> # data data
> data
> data data data *
> # more dataaa
> moreeee *
>
> Basically I want to slurp that file in, then search for # and extract
> all the data up to the * and print it, new line, next set of data.

I assume you mean that the whitespace after '#' and before '*' is not part of
the data (else, remove the \s* in the regex below).

The following just one (of the shorter) way to do it; read the expression
beginning with 'print' bottom-up:

======
#!/usr/bin/perl

use strict;
use warnings;

local $/;
my $content=<DATA>;
print join "\n",
map { do {$_=~s/\n/ /gs; $_} }
$content=~/#\s*(.*?)\s*\*/gs;

__DATA__
# data data
data
data data data *
# more dataaa
moreeee *
======

see

perldoc -f map
perldoc -f do
perldoc perlre

and for opening/closing an external file:
perldoc -f open
perldoc -f close

hth, joe

John W. Krahn

2006-01-24, 6:56 pm

Chris wrote:
> Hi list,

Hello,

> I am not sure if there is a proper name for this but was having some
> difficulty searching for it.
>
> Basically I have data in a file that is between two different
> characters, for example:
>
> # data data
> data
> data data data *
> # more dataaa
> moreeee *
>
> Basically I want to slurp that file in, then search for # and extract
> all the data up to the * and print it, new line, next set of data.
>
> Any pointers would be great.

From your example it looks like you could set the Input Record Separator to
something like "*\n".

John
--
use Perl;
program
fulfillment

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