Little history behind mod_sed filter module
By Basant Kukreja on Aug 15, 2008
In this blog, I will cover the history behind the mod_sed code. Solaris 10 has two separate "sed" utilities, one in /usr/bin/sed and another in /usr/ucb/sed. The later one is open sourced under CDDL and available in opensolaris. Sun Java System Web Server 7.0 initially included sed filter module. Sun Web Server filter module was derived from "/usr/bin/sed" code and it was written by Chris Elving
Last year, I took the Sun Web Server code and wrote the mod_sed based on Web Server code. The difference between Sun Web Server sed filter module and mod_sed is that mod_sed is derived from /usr/ucb/sed code. Sun Web Server's sed filtering module uses NSPR for portable API while mod_sed uses APR since it runs under Apache which uses APR for portability.
Functionality wise "/usr/bin/sed" code was little better than "/usr/ucb/sed" but I have fixed some of the limitation of "/usr/ucb/sed" in mod_sed e.g max number of characters in a line or hold buffer.