Re: reg. expr. multiple substitutions

[Eliya]

You could alias $_ to $str, which would allow you to at least get rid of the repetitive "$str =~ " part in every line.

Other than that, you do have to declare somehow what to replace with what, and this get can hardly get any more compact than a list of s/.../.../ (unless there is some pattern or regularity in the tag-substitution pairs that would allow you generate them automatically — but I suppose the ones given are not the real ones).

for ($str) {
    s/tag1/subst1/;
    s/tag2/subst2/;
    s/tag3/subst3/;
    ...
    s/tag49/subst49/;
}