topic Re: Escaping a forward slash in pattern in NSO Developer Hub Discussions

Escaping a forward slash in pattern

ysolan — Fri, 01 Mar 2019 11:52:53 GMT

Hi Team,

So far, I used the following pattern in the yang "[a-z0-9 -] *" for per example matching this string : switch01-dev001

Now, i'm looking for matching also forward slash /

i changed the pattern to "[a-z0-9-/]*" but i doesn't work. I would like to match the following string : switch01-dev/001

Do you have an idea ?

Regards,

Yannick

Re: Escaping a forward slash in pattern

Chri_Erenti — Wed, 21 Jun 2017 16:04:28 GMT

Hi Yannick,

maybe you have to precede it with the backslash: "[a-z0-9-\/]*"

Best Regards

Christian

Re: Escaping a forward slash in pattern

ysolan — Wed, 21 Jun 2017 16:22:53 GMT

Hi Christian,

Thanks, I tried "[a-z0-9-\/]*"

But i have this ouput after a make :

.yang:22: error: invalid pattern: "Bad Pattern"

.yang:22:20: warning: illegal character after \

Best Regards,

Yannick

Re: Escaping a forward slash in pattern

Hiro Takahashi — Wed, 21 Jun 2017 17:39:03 GMT

Hello Yannick,

I think solution here is to escape "-" instead of "/".

Without "-", it looks pattern is working with forward slash.

leaf dummy {

type string {

pattern "[a-z0-9/]+";

}

admin@ncs(config)# ytest test dummy dev/001

admin@ncs(config-ytest-test)#

If I add "-", it fails because "-" means a range.

type string {

pattern "[a-z0-9-/]+";

}

admin@ncs(config)# ytest test dummy switch01-dev/001

------------------------------------^

syntax error: "switch01-dev/001" is an invalid value.

admin@ncs(config)#

So, if I escape "-" then it works.

type string {

pattern "[a-z0-9\-/]+";

}

admin@ncs(config)# ytest test dummy switch01-dev/001

admin@ncs(config-ytest-test)#

By the way, I prefer using "-" outside of [] such as follows.

type string {

pattern "[a-z0-9]+\-dev/[0-9]+";

}

Hope this helps.

Best regards,

Hiro

Re: Escaping a forward slash in pattern

Chri_Erenti — Wed, 21 Jun 2017 17:50:48 GMT

Thank you Hiro,

you're right!

"-" is a special character inside the square brackets. Outside it is not.

It should work also in this way: "[a-z0-9]+-dev/[0-9]+" or more generic: "[a-z0-9]+-*/*"

Let me know.

Best Regards

Christian

Re: Escaping a forward slash in pattern

Hiro Takahashi — Wed, 21 Jun 2017 18:00:10 GMT

Hello Christian,

Indeed, "-" should work without escaping outside of square brackets as "[a-z0-9]+-dev/[0-9]+".

Thank you for the correction!

Best regards,

Hiro

Re: Escaping a forward slash in pattern

ysolan — Thu, 22 Jun 2017 07:31:22 GMT

Hi guys,

Thanks a lot, you have helped me to better understand the structure.

My final generic pattern is : "[a-z0-9]*-*/*";

Best regards,

Yannick

Re: Escaping a forward slash in pattern

Jan Lindblad — Thu, 22 Jun 2017 12:36:00 GMT

You could use [a-z0-9/-]*

Placing the dash last within the brackets is a 40-year old trick. That ensures it's not treated as part of any character range.

/jan