Re^4: You won't believe what this regular expression does!

[haukex]

But please note the second fOO

Yes, good point! I think the main question is what the intent of the regex is. If it's "replace any o's at the end of each line", then the better solution is, as you said, /o+$/, and using o* is the "mistake".

[salva]

No, the intent is to ensure that the string ends in just one o, no less, no more than one.

In real life, those lines were paths, and I wanted all of then ending in a single slash. For instance:

/foo  --> /foo/
/foo/ --> /foo/
/foo////// --> /foo/

[haukex]

In real life, those lines were paths, and I wanted all of then ending in a single slash.

Ah, I see. You want canonpath from File::Spec ;-) (doesn't add the trailing slash, but there are multiple possible solutions for that as well)

And this is admittedly not the prettiest solution, but it works: s{(?| /* (\n) | /+ (\z) | [^/] \K (\z) )}{/$1}mgrx. Or just split the input string on \n...

[LanX]

> No, the intent is to ensure that the string ends in just one o, no less, no more than one.

And how did you solve it in the end?

...

You won't believe how I did this!

<Reveal this spoiler or all in this thread>

;-P

[salva]

"hello\nhell\nhelloooo\nhello" =~ s/o+$//gmr =~ s/$/o/gmr