Regex: How to get matched content?

RouterOS Scripting
1

Hi,

I am not sure Mikrotik support this basic function.

The need is to parse a string and extract some content based on regex.
I think mikrotik can only return true/false if the regex is matched, but can’t return $1, $2 … based on the matches (like any other coding language would be capable of doing).

For example the script below, where I would like the script to return the regex match between parenthesis.
$1 returns nothing

:local regexTestString "my test string bla bla"

:if ( $regexTestString ~".*(test.*)" ) do={
	:put "regex match: $1"
}

returns:

regex match:

I have searched through the forum and google.
Very few results. The closest I was able to find was a response to an open discussion on feature requests, but no conclusion or follow-up:
http://forum.mikrotik.com/t/built-in-function-library/117288/2

Is there something obvious I’m missing, or is the feature simply absent?

Thanks

2

What you is looking for is called capturing group.
It des not look like RouterOS support capturing group or named capturing group.

{
:local regexTestString "my test string bla bla"

:if ( $regexTestString ~".*(?<tt>test.*)" ) do={
	:put "regex match: $tt"
}
}

RouterOS regex info:
https://wiki.mikrotik.com/wiki/Manual:Regular_Expressions

3

Thanks for your response,

I guess each language can have its own naming next to this feature, “capturing group” being one of them.
Perl calls it “extracting matches”, boen_robot in his post referenced earlier called it “regexmatch”
If it gets returned as $1 $2 would already be good (ie: without the capacity to tag each return with a distinctive name)

Not great to have this as unsupported considering that Mikrotik OS initially offsprings from a Linux distribution

Thanks for your update on the script.
I don’t get anything returned when running it, which is I guess expected as you called out this feature as being “unsupported”

I obviously went to the regex page of mikrotik, but it’s really short of ~20 lines.
It only states it follows POSIX (with 5 listed exceptions in bullet points), and list 8 areas where the Mikrotik device could use regex.
That’s it. There are no screenshot, implementation examples, scripts templates.

Eventually my workaround was partial, suboptimal, and involved nested string split/pick

Cheers