Training, Open Source computer languages
PerlPHPPythonMySQLApache / TomcatTclRubyJavaC and C++LinuxCSS 
Search for:
Home Accessibility Courses Diary The Mouth Forum Resources Site Map About Us Contact
Python, Lua and Tcl - public course schedule [here]
Private courses on your site - see [here]
Please ask about maintenance training for Perl, PHP, Java, C, C++, Ruby, MySQL and Linux / Tomcat systems
Regexp problem

Posted by vinay_techie4u (vinay_techie4u), 5 May 2006
Hii Evrybody..

M new to TCL , only 1 week..
Can U plz tell  me  the single Regexp for valid IP address.

thanx in advance

Posted by admin (Graham Ellis), 5 May 2006
You cannot easily check for a valid IP address in a single regular expression;   regular expressions are great for character handling but they get a bit trickier when it comes to checking number ranges.

As an alternative, you should:

a) Check the basic structure of the address (1 to 3 digits, dot, 1 to 3 digits, dot, 1 to 3 digits, dot, one to three digits) using a regular expression

b) Split the string that you're checking at the "." charcater and check each 4 elements of the resulting list to ensure that it's in the range 0 to 255.

You can extent this is you wish to check that you have the real address of a computer rather than a broadcast address by adding extra tests.

Posted by vinay_techie4u (vinay_techie4u), 5 May 2006
Thanx Graham..

yeh..I had already implemented in the same way as you said..

But one of mine frnd. wants it to be in a single regexp

anyways thanx a lot for your quick responce.

also plz suggest me what should I do, to have gud

understading of TCL as m new to programming ..just

now shifted from QA to Devlopment.

Your suggestion will help me in getting on right track..



Posted by admin (Graham Ellis), 5 May 2006
Trying to do everything in a single regular expression is a bit "macho" - people try to do it but they end up looking a bit silly when they overstretch.

How can you learn Tcl?   Well ... as a trainer who teaches Tcl courses I have to recommend our Tcl course, now don't I?  

This page is a thread posted to the opentalk forum at and archived here for reference. To jump to the archive index please follow this link.

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2018: Well House Manor • 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01225 708225 • FAX: 01225 793803 • EMAIL: • WEB: • SKYPE: wellho