in reply to RegExp to Search All Array Members?

You were SO close. 
my $regexStr="^static\s+\w+\s+("
                       # Thanks moritz!
           . (join "|",map quotemeta,@names)
           . ")\W.*)";

while(<STDIN>) {
   chomp;

   if(/$regexStr/) {
   # rest is the same as your "optimized"
   # attempt

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Mike

Edit: added map quotemeta as suggested by moritz

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Re^2: RegExp to Search All Array Members?
by moritz (Cardinal) on Jun 19, 2007 at 10:26 UTC
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Re^2: RegExp to Search All Array Members?
by ff (Hermit) on Jun 19, 2007 at 13:19 UTC
    Having just read the section in Damian's Object Oriented Perl book about the regular use of qr, this looked like a good chance to try it out. That is, with qr, you are creating a reference to a regular expression which you can store in a scalar variable. When that scalar variable is used in a regex later on, the complilation work to prepare the referenced regex doesn't have to be repeated each time through your loop, avoiding a good amount of regex overhead.

    Here's the snippet again with some tweaks to your example. Note, whenever I store a reference in a scalar, I like to suffix the identifier with _Xr, where X stands for the kind of thing that's supposed to be referenced (in this case r for "regex") and the closing r indicates that the scalar is supposed to hold a reference.

    #!/usr/local/bin/perl -w
use strict;

my @names = ("John?", "Paul", "George", "Rin.go");

my $regexStr
    = "^static\\s+\\w+\\s+("
                # Thanks moritz!
    . (join "|",map quotemeta,@names)
    . ")\\W.*";
print "$regexStr\n\n";

my $regexStr_rr = qr{$regexStr}i; # or "cloister" the 'i' in $regexStr

while(<DATA>) {
    chomp;

    my ( $hit )
        = $_ =~ /$regexStr_rr/;
  
    if ($hit) {
        print "Beatle method \"$hit\" found on this line: $_\n";
    }
    else {
        print "No Beatle method found on this line: $_\n";
    }
}

__DATA__
static int lars(...);
static bool george(...);
static int thom(...);

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[d/l]
[select]

      I have tried to get this working, but have been unsuccessful. I am a noob to programming and perl so patience would be appreciated.

      The search NEVER matches. I made sure the case is exactly the same in the doc and still no luck

      Here is the code

       
#!/usr/bin/perl -w

use strict;
use warnings;

open(FH, "Wachterpdf2txt.txt") or die "We have a problem: $!";

my @invoiceSearch = ("phone", "hunt", "dial", "tone", "static", "18d",
+ "system", "voice", "numbers", "voicemail", "MLX201", "programming", 
+"extension", "processor", "block", "mls", "programmed", "rollover", "
+extension", "partner", "crosstalk", "merlin", "ringing");

my $regexStr="^static\\s+\\w+\\s+(" . (join "|",map quotemeta,@invoice
+Search) . ")\\W.*";

print "$regexStr\n\n";

my $regexStr_rr = qr{$regexStr}i; # or "cloister" the 'i' in $regexStr

while(<FH>) {
   chomp;
    my ( $hit )
        = $_ =~ /$regexStr_rr/;
  
    if ($hit) {
        print "Beatle method \"$hit\" found on this line: $_\n";
    }
    else {
        print "No Beatle method found on this line: $_\n";
    }
}

      [download]

      What I can't seem to find anywhere is what the ^static statement means in the Regex variable. I am pulling in a text document that was converted from .pdf I have stripped out all spaces and most punctuation. The text document looks fine to me.

      Any help would be appreciated!

[reply]
[d/l]
        A bit late, but...

        ^ is a special character in regex that makes it find the match at the beginning of the string. So with '^static', it will find any string that begins with 'static'.

        So, it would match:
        static bool fred(...)

        But it wouldn't match
        stat bool fred(...)

        since static isn't at the very beginning of it, stat is.
[reply]
Re^2: RegExp to Search All Array Members?
by johngg (Canon) on Jun 19, 2007 at 13:33 UTC
    An alternative to using join and string concatenation when making the pattern would be to change the default list separator from a space to the pipe symbol and use interpolation with the array or list.

    $ perl -Mstrict -Mwarnings -le '
> my @arr = qw{abc d.ef gh?i};
> my $patt;
> {
>     local $" = q{|};
>     $patt = qq{xyz(@{ [ map quotemeta, @arr ] })123};
> }
> print $patt;'
xyz(abc|d\.ef|gh\?i)123
$

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    You can also use this method with qr{...} which behaves like double quotes.

    Cheers,

    JohnGG

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