Perl deferred interpolation of string - regex

Question

I have a situation where there is a triage script that takes in a message, compares it against a list of regex's and the first one that matches sets the bucket. Some example code would look like this.
my $message = 'some message: I am bob';
my #buckets = (
{
regex => '^some message:(.*)',
bucket => '"remote report: $1"',
},
# more pairs
);
foreach my $e (#buckets) {
if ($message =~ /$e->{regex}/i) {
print eval "$e->{bucket}";
}
}
This code will give remote report: I am bob. I keep looking at this and feel like there has to be a better way to do this then it is done now. especially with the double quoting ('""') in the bucket. Is there a better way for this to be handled?

Answer 1

Perl resolves the interpolation when that expression is evaluated. For that, it is sufficient to use a subroutine, no eval needed:
...
bucket => sub { "remote report: $1" },
...
print $e->{bucket}->();
Note that you effectively eval your regexes as well. You can use pre-compiled regex objects in your hash, with the qr// operator:
...
regex => qr/^some message:(.*)/i,
...
if ($message =~ /$e->{regex}/) {

Answer 2

You could use sprintf-style format strings:
use strict;
use warnings;
my $message = 'some message: I am bob';
my #buckets = (
{
regex => qr/^some message:(.*)/,
bucket => 'remote report: %s',
},
# more pairs
);
foreach my $e (#buckets) {
if (my #matches = ($message =~ /$e->{regex}/ig)) {
printf($e->{bucket}, #matches);
}
}