Need a regular expression match for finding and replacing a pattern

Question

Here is my string:

string = "abcdef.sfdsf_3asafds-fdsfd;info=<http://www.amazon.com:8080/abc/ads/asdf>;tag=abc123;val=hello"

My goal using gsub/sub in ruby to replace:

info=<http://www.amazon.com:8080/abc/ads/asdf>

with:

info=<private-url>

I tried a few attempts using regexp but they are buggy. Any advice?

The important thing to remember here is showing your attempts helps considerably. You may be as little as one character away from a solution and it's easy for someone to spot and fix that than to start from nothing. — tadman, Jul 21 '17 at 20:31
No, it can be anything. My need is to "replace" the complete info= with a user provided url. — Gaurav, Jul 21 '17 at 20:33
@tadman, a very simple solution that I tried was `<.*>`. But this is buggy, since the user can also change the info= with a different string. — Gaurav, Jul 21 '17 at 20:42

Iuji Ujisato · Accepted Answer · 2017-07-21T21:23:27.063

1

A simple regex to do it can be /<(.*?)>/

This will match everything inside < > (including the < > signals).

Keep in mind that this will match the first occurrence on string.

You can check the explanation for the regex on this question.

You can also check it on Rubular, a great tool to test ruby regex on fly.

In order to replace the match result in Ruby you can try something like 2.4.0 :024 > string.sub(/<(.*?)>/, '<your_url>') => "abcdef.sfdsf_3asafds-fdsfd;info=<your_url>;tag=abc123;val=hello"

This can be used on this string, but you need to adapt it on your use if there are more < > signals on the string.

edited Jul 21 '17 at 21:23

answered Jul 21 '17 at 21:15

Iuji Ujisato

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It's worth noting here that `<.*>` means *longest* possible match, while `<.*?>` means *shortest* possible. The difference here is how you avoid your expression getting too "greedy". – tadman Jul 22 '17 at 23:09
Sorry, I didn't worte that becaus I've linked another question that explains it. Should I copy/paste it here for better understanding for future viewers? – Iuji Ujisato Jul 26 '17 at 20:02

Need a regular expression match for finding and replacing a pattern

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