This is a bit tricky because there are a variety of escape types to handle. In particular, there are the "regular" codes like '\n' which translate into a single character, but there are also others.
  1. '\cX' is the equivalent of CTRL-X, where X is a letter from a to z, or also a few others in the nearby ASCII space (such as ESC).
  2. '\xNN' is the ASCII character hexidecimal 0xNN.
  3. '\0nnn' is the ASCII character octal nnn.
You could build a regex to handle these, perhaps, such as: 
my %escape = map { ( chr($_) => eval '"\\'.chr($_).'"'||undef ) } 0 ..
+ 127;

sub interpolate
{
        my ($s) = @_;

        $s =~ s/\\c(.)/chr(ord(lc($1))-ord('`'))/ge;
        $s =~ s/\\x([a-fA-F0-9]{2})/chr(hex($1))/ge;
        $s =~ s/\\0([0-9]{1,3})/chr(oct($1))/ge;
        $s =~ s/\\0/\0/g;

        $s =~ s/\\(.)/$escape{$1}/gs;

        return $s;
}

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In reply to Re: Selective string interpolation by tadman
in thread Selective string interpolation by ton

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