pattern matching -- feeling stoopit

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

It's been a while since I've sat down and written any Perl (as will become obvious).

I'm using a regexp to parse thru a file that contains output from a grep. The grep was on the pattern "*.pl" -- I went and greped for all html files that are calling perl scripts on my site.

I'm trying to do a pattern match for "pl", and print the match, which hopefully will give me a nice list of all the perl scripts with no extraneous html.

Here's the code that doesn't get a match for anything (right now I'm just printing to stdout until I figure out why the regexp isn't matching):

#!/usr/bin/perl


open FILE, "grepfile" or die "where is grepfile?";

while ( $blah = <FILE> ) {

$blah =~ /pl/;

if ($1) {

print $1

} else {

print "no match"

}
}

print $1;

close FILE;

exit;
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Re: pattern matching -- feeling stoopit by Caillte (Friar) on Oct 02, 2001 at 20:36 UTC
This looks like homework but.... `m/(pl)/` will store a value in $1, `m/pl/` won't. It's the brackets that define what gets written to $n `$japh->{'Caillte'} = $me;`	[reply] [d/l] [select]
Re: Re: pattern matching -- feeling stoopit by Anonymous Monk on Oct 02, 2001 at 20:43 UTC
$doh == true; It ain't homework--I wish I was taking a refresher course though. Much thanks!	[reply]
Re: pattern matching -- feeling stoopit by arturo (Vicar) on Oct 02, 2001 at 20:50 UTC
What's in `grepfile` ? The output of your grep ? (which is what, exactly? `filename: [ matching line ]` ? -- I'll assume that) You need to put capturing parens in the regex for $1 to get set by a successful match. Now, assuming valid filename characters are `\w` (not quite true, but probably OK in the present context) what you want to match is not just the "pl" but the "." that comes before it and a bunch of word characters before that. And you probably only want the ones that are referenced within form `action` tags, for that matter, but let's leave that for a future refinement. So the regex you want matches "one or more word ( \w ) characters, followed by a literal ., followed by 'pl'." => `/\w+\.pl/` (\w character => one or more => a literal dot => "pl" ). Toss in the parentheses, and make the match case-insensitive (maybe necessary, maybe not), and use some nifty shorthand to put the results of `$1` into a variable, and you get: `while ( my $blah = <FILE> ) { if (my ($filename) = ($blah =~/(\w+\.pl)/i) ) { print "$filename was found.\n"; } else { print "no match.\n"; } }` [download] HTH `perl -e 'print "How sweet does a rose smell? "; chomp ($n = <STDIN>); +$rose = "smells sweet to degree $n"; other_name = rose; print "$oth +er_name\n"'` [download]	[reply] [d/l] [select]