Providing regex using an array

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

Perl Monks, I am trying to use an array to list regex search choices. Code works if a single regex is inputted.

use strict;
use warnings;

sub main
{
    
      my @patterns = ("^abd", "ghi");
    my $file = 'C:\Perl64\bin\hello.txt';
    open(FH, $file) or die("File $file not found");
    
    while(my $String = <FH>)
    {
#         if($String = ~ /^abd /)
                if($String .= join ('/ && /', @patterns);
        {
            print "$String \n";
        }
    }
    close(FH);
}
main();
[download]

Error: Global symbol "@patterns" requires explicit package name at pattern2.pl line 7. Global symbol "@patterns" requires explicit package name at pattern2.pl line 14. syntax error at pattern2.pl line 14, near ");" Execution of pattern2.pl aborted due to compilation errors. What syntax error am I making? Best, David

Comment on Providing regex using an array Download Code

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Re: Providing regex using an array by haukex (Archbishop) on Sep 09, 2022 at 22:12 UTC
You have unbalanced parens in your `if`, the semicolon on that line should be a closing paren. If I understand correctly what your code is trying to do, you may be interested in my tutorial Building Regex Alternations Dynamically.	[reply] [d/l]
Re: Providing regex using an array by LanX (Saint) on Sep 10, 2022 at 00:17 UTC
First of all please fix your indentation, you seem to be mixing spaces and tabs. This might look ok in your editor, but your tab-length is 8 while we use 4 here. It's hard to tell what you are trying to achieve, my best guess is to check that all regexes in an array individually match. the following debugger-demo is using the fact that grep returns a count in scalar context `> perl -de0 DB<134> @patterns = ("^abd", "ghi"); DB<135> $string = "abd__ghi__" DB<136> p @patterns == grep { $string =~ $_ } @patterns 1 DB<137> DB<137> $string = "abd__xhi__" DB<138> p @patterns == grep { $string =~ $_ } @patterns DB<139>` [download] even easier if you use `all` from List::Util `DB<139> use List::Util qw/all/ DB<140> $string = "abd__ghi__" DB<141> p all { $string =~ $_ } @patterns 1 DB<142>` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]
Re^2: Providing regex using an array by dgrunwal (Initiate) on Sep 11, 2022 at 20:00 UTC
Thank you! Best, Dave	[reply]