I don't see anything wrong with your regex. I tried

print "$1\n$2\n" if $var =~ /^\((.*)\),(.*)$/;
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on your string and got

this is a good idea!
 No it's not
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exactly as I would expect.

On a slightly different topic, I would have generally used ([^)]*) rather than (.*) as the first capture. It is more likely to do what you want.

The usual approach is this:

my $regex = qr{
     ^          # anchor
     \(         # opening paren
     ([^)]*)    # everything but a closing paren, captured in $1
     \)         # closing paren
     ,(.*)      # the rest, captured in $2
     $
}xs;
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use strict;
use warnings;
use Data::Dumper;

my $var = "(this is a good idea!), No it's not";
if ( $var =~ /^(\(.*\)),(.*)$/ ) {
    my @args = ($1, $2);
    print Dumper(\@args);
} 

__END__

$VAR1 = [
          '(this is a good idea!)',
          ' No it\'s not'
        ];
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Also, it would be easier to read your post if you did not use "pre" tags.

Good answers above; suggestion below as a variant way of saying "Welcome to the Monastery."

Please read:

• On asking for help which may help understand why Monks asked that you outline your expectations (specfically, what you wanted) and what you actually got (as it's not absolutely clear whether you want to capture the enclosing parens or not).
• Then check Markup in the Monastery and Writeup Formatting Tips for formatting guidance (hint: pre is strongly discouraged.)

Re your code: Note that the [ ... ] does NOT "escape" the character(s) it encloses in the usual sense (though it will cause the paren to be treated as a literal, in a regex). But so too will the customary escape character, the backslash (\).

If you plan to do much with Perl regexen, Mastering Regular Expressions (ca $US45.) and/or O'Reilly's "Regular Expressions Pocket Reference" ( <$US10.) are well worth the investment.

You may also wish to look into Text::Balanced. extract_bracketed looks like it would do the trick for you.

I've updated the question to give more information.

Of course, I can always avoid this problem by doing something like this:

    $sub_p_tmp[$i] =~ s/[()]//;
    if ( $sub_p_tmp[$i] =~ m/^(.*)\,(.*)\,(.*)[,;]$/ )
    { @args = ($1, $2, $3); }
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But I feel like that's cheating. I want to know why the the original way doesn't work!! :)

Seems I'm running into a problem with the comma when I remove the brackets like that... ah well, need to experiment a bit more.

I've been able to resolve the this with the following code, which seems to give me the output I'm looking for:

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

my $data = "U|(Memory is incorrectly balanced between the NUMA ";
$data .= "nodes of this system, which will lead to poor performance.  
+";
$data .= "See),_NUMA_CRIT_,;(/proc/vmware/NUMA/hardware),_NUMA_CRIT_";
$data .= ",__REFERAL__file:__SELF__;( for details on your current ";
$data .= "memory configuration),_NUMA_CRIT_,;";


(my $m_type = $data) =~ s/^((?:U|M))\|.*$/$1/;
(my $p_list = $data) =~ s/^(?:U|M)\|(.*)$/$1/;
my @sub_p_tmp = split(/;/,$p_list);

print "sub_p_tmp:\n";
print Dumper(@sub_p_tmp);

my @args;
for ( my $i = 0; $i <= $#sub_p_tmp; $i++ )
{
    $sub_p_tmp[$i] =~ s/,$//;
    if ( $sub_p_tmp[$i] =~ m/^\((.*)\),(.*),(.*)$/ )
    { push @args, ($1, $2, $3); }
    elsif ( $sub_p_tmp[$i] =~ m/^\((.*)\),(.*)$/ )
    { push @args, ($1, $2); }
}


#print "$m_type\n\n$p_list\n\n".Dumper(@sub_p_tmp)."\n";

print "\nArgs:\n";
print Dumper(@args)."\n";
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Try this.

#!/usr/bin/perl -w

use strict;
use warnings;

use Data::Dumper;

my $data = join '', 
       "U|(Memory is incorrectly balanced between the NUMA ",
       "nodes of this system, which will lead to poor performance.  ",
       "See),_NUMA_CRIT_,;(/proc/vmware/NUMA/hardware),_NUMA_CRIT_",
       ",__REFERAL__file:__SELF__;( for details on your current ",
       "memory configuration),_NUMA_CRIT_,;";

print "DATA\n$data\n\n";

#(my $m_type = $data) =~ s/^((?:U|M))\|.*$/$1/;  # gets U
#(my $p_list = $data) =~ s/^(?:U|M)\|(.*)$/$1/;  # gets U, i think thi
+s is the reason you weren't getting anything

# This approach does what I think you are trying for without as much w
+ork for you or the computer.
my ($m_type, $p_list) = split /\|/, $data, 2;

my @sub_p_tmp = split /;/, $p_list;

print "MTYPE: $m_type\n";
print "PLIST: $p_list\n";

my @args;

# Try using
# for my $p_tmp ( @sub_p_tmp ) 
# Instead of the c style for loop, unless you are processing HUGE arra
+ys.
for ( my $i = 0; $i <= $#sub_p_tmp; $i++ )
{
    print "$i:  $sub_p_tmp[$i]\n";
# Here's your regex based method fixed to work
#    if ( $sub_p_tmp[$i] =~ m/^\(([^)]*)\),([^,]*),(.*)$/ )
#    {
#        @args = ($1, $2, $3); 
#    print "\nArgs:\n"; 
#    print Dumper(\@args)."\n";
#    }

# Here's a split based approach. 
# in both approaches @args is overwritten each pass through the loop. 
    my @temp = split /,/, $sub_p_tmp[$i]; 
    if ( @temp )
    {
        # Get rid of the extra parens.
        $temp[0] =~ s/^\(|\)$//g;

    # Overwriting the value of @args each time.
    # Do you mean 
    #    push @args, @temp[0..2];
    #     or
    #    push @args, [ @temp[0..2]];
        $temp[0] =~ s/^\(|\)$//g;

        @args = @temp[0..2];
    print "\nArgs:\n"; 
    print Dumper(\@args)."\n";
    }
}
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TGI says moo

Thanks TGI, I'll definitely play around with this!