Solaris has a crippled version of awk - which is the default. It also has nawk which is more like new awk and supports features.

There are POSIX standards for awk which came out long after the awk version Solaris has...

see:
http://www.opengroup.org/onlinepubs/...ities/awk.html

POSIX is a set of standards developers of most flavors of UNIX try to follow.
This allows, for example, somebody here running Linux to get an example from someone else on this forum - that other person runs Solaris - and there will be a good chance it works on both boxes. Solaris doesn't play POSIX with awk, but it's there to support old code. Just use nawk and forget awk. IMO.