regular expression for XML

[ca_374]

Hi,

 

I'm currently testing a software based AAA(authentication, authorization, accounting) server from http://www.tacacs.net/ and this requires me to use regular expression to authorize specific Cisco commands when users are logged in to our switches.

 

I'm very new to regular expression and I need help to make the "authorization" part of this AAA server works. I've been searching the Internet and trying different syntax of regular expression for XML but I was unsuccessful.

 

What I'm trying do is, match the exact command "show running-config interface fasthethernet 1/0/1".(the "1/0/1" entry is up to "1/0/52"). Also, I would like to match the same command when the user type the shortcut method like "sh run int fa1/0/1". If I could make this work, I could apply the same syntax to other commands that I would like to either permit or deny.

 

If someone could give me an idea how I can make it work, I would appreciate. I attached the authorization.xml file and if you need additional information, just let me know. Based on the attached file, the <Shell> </Shell> section is what I'm working on:

 

<Shell>

<!--note that the login and exit commands are always permitted-->

<Permit>configure terminal</Permit> <Permit/>

</Shell>

 

Thanks!

authorization.xml

Edited November 13, 2013 by ca_374

[justsomeguy]

Regular expressions are for pattern matching, not really meant for finding specific strings. If you want to find a specific string then your regular expression pattern is the exact string you're looking for. You may need to escape certain characters that have a meaning in regular expressions, like . + * ? etc, but other than that if you're looking for a specific string then your pattern is that string.

 

Matching a range of numbers like 1 through 52 is more complicated, you need to do it in parts. It could be a single-digit number, 1-9, so you would need this:

 

[1-9]

 

or, there could be 2 digits, where the first goes through 1 to 4 and the second goes through 0 to 9, to match 10-49, which is this:

 

[1-4][0-9]

 

then to match 50-52:

 

5[0-2]

 

so you put all of those together to get 1 through 52:

 

([1-9])|([1-4][0-9])|(5[0-2])

[ca_374]

Thanks for the reply justsomeguy.

 

how can i properly add the character "/" on the syntax that you gave? the character "/" needs to be part of the command.

 

Thanks.

[justsomeguy]

You can escape any regular expression meta-character by putting in front of it.