Passing a regex substitution as a variable in Perl?

Question

I need to pass a regex substitution as a variable:

sub proc {
    my $pattern = shift;
    my $txt = \"foo baz\";

    $txt =~ $pattern;
}

my $pattern = \'s         


        

Answer 1

I found a probably better way to do it:

sub proc {
    my ($pattern, $replacement) = @_;
    my $txt = "foo baz";

    $txt =~ s/$pattern/$replacement/g;  # This substitution is global.
}

my $pattern = qr/foo/;  # qr means the regex is pre-compiled.
my $replacement = 'bar';

proc($pattern, $replacement);

If the flags of the substitution have to be variable, you can use this:

sub proc {
    my ($pattern, $replacement, $flags) = @_;
    my $txt = "foo baz";

    eval('$txt =~ s/$pattern/$replacement/' . $flags);
}

proc(qr/foo/, 'bar', 'g');

Please note that you don't need to escape / in the replacement string.