The OPed sort of problem is tricky, but for this
specific iteration:
Win8 Strawberry 5.8.9.5 (32) Wed 11/25/2020 22:12:13
C:\@Work\Perl\monks
>perl
use strict;
use warnings;
my $pattern = '(testing)';
my $replacement = 'New \U$1';
my $flags = 'i';
my $value = 'My Testing Text';
### $replacement =~ s/\\/\\\\/g;
print "replacement '$replacement' \n";
eval "\$value =~ s/$pattern/$replacement/$flags";
print "$value\n";
^Z
replacement 'New \U$1'
My New TESTING Text
(An escaped backreference
\1 is not kosher in a replacement
string anyway; it should be in
$1 form.)
Update: Here's a version of the example code that better
illustrates the process of building the evaluation string:
Win8 Strawberry 5.8.9.5 (32) Wed 11/25/2020 22:45:44
C:\@Work\Perl\monks
>perl
use strict;
use warnings;
my $pattern = '(testing)';
my $replacement = 'New \U$1';
my $flags = 'i';
my $value = 'My Testing Text';
print "replacement '$replacement' \n";
my $eval_string = "\$value =~ s/$pattern/$replacement/$flags";
print "eval_string '$eval_string' \n";
eval $eval_string;
print "$value\n";
^Z
replacement 'New \U$1'
eval_string '$value =~ s/(testing)/New \U$1/i'
My New TESTING Text
Give a man a fish: <%-{-{-{-<