IP+MASK regexp

grzeslaw · 07-09-2019, 04:33 AM

Hi,

I am trying to write regexp to validate IP address and netmask. Sadly my regexp still catch wrong netmask:

Code:

  IP_ADDR_REGEXP="(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))"

Could anyone help me with fixing that? Netmask should be 2integers long and be in range 1-32..

pan64 · 07-09-2019, 08:05 AM

regex101.com can be useful to construct regex
without example and the used language hard to say anything.

scasey · 07-09-2019, 08:43 AM

Mayhaps this will help:
https://www.regextester.com/22

astrogeek · 07-09-2019, 11:05 AM

It would be helpful if you would tell us more precisely what qualifies as valid. It is not possible for others to derive the conditions of validity from your regex when you have already said it does not produce the desired result.

Please tell us more precisely what networks you want to match, with an example of matching and non matching IP.

Please review the Site FAQ for guidance in posting your questions and general forum usage. Especially, read the link in that page, How To Ask Questions The Smart Way. The more effort you put into understanding your problem and framing your questions, the better others can help!

grzeslaw · 07-10-2019, 06:57 AM

Thanks for your comments guys, appreciate that!
Honestly, I want to match all available local and external networks with mask up to 32.
for example:

Code:

10.0.10.0/24
200.211.15.0/28
212.5.0.0/19
172.20.0.0/20
144.44.0.4/32

Kenhelm · 07-10-2019, 08:02 AM

The regex needs a '$' end-of-line anchor to stop it matching substrings.
......|[0-9]))$"

Code:

echo /{0..255} | tr ' ' '\n' |     # /0 to /255
grep '/[0-9]$'                     # Without the $ it would match all of /0 to /255
/0
/1
/2
/3
/4
/5
/6
/7
/8
/9

grzeslaw · 07-10-2019, 09:50 AM

Quote:

Originally Posted by Kenhelm

The regex needs a '$' end-of-line anchor to stop it matching substrings.
......|[0-9]))$"

Code:

echo /{0..255} | tr ' ' '\n' |     # /0 to /255
grep '/[0-9]$'                     # Without the $ it would match all of /0 to /255
/0
/1
/2
/3
/4
/5
/6
/7
/8
/9

And the winner is.... Kenhelm!
Thanks a lot mate!
That's what I miss - just one magic dollar!