README for sourceHoudini.py

This Python script is intended to be run from a unix shell environment and is
used to easily source a Houdini environment.

The script works by utilizing the houdiniutils.py module to search the system 
for installed Houdini builds and allow you various flexibility to source
an environment.  By default the script expects that you have installed
Houdini in the default location on either linux or OS X.  This can also
be changed in the module.

This system works by writing the install path ($HFS) to a temp file which 
can then be read to provide a path from which to initialize Houdini.

Various arguments can be passed to the script to help specify which exact
build is desired.  If an invalid arg is passed or the specified build cannot
be found an error is printed to stderr and the latest version is chosen.

- No args will result in the latest build (highest number) being sourced.
- The character 'l' or 'list' will result in a list of all found builds being
displayed and prompting for a choice.
- 1 or 2 digits means major build (9.#.#, 10.#.#, 11.#.#, etc.)
- 3 digits means build number (#.#.361, #.#.725, etc.)

Pieces are '.' separated and can be used for major/minor or full version 
selection.
- 2 pieces means we are trying to choose with a major + minor choice. 
(9.5, 10.0, 10.5, etc)
- 3 pieces means we are trying to choose with a full build number (11.0.123)


Here is an example of using it from within the .bashrc file.  In this example
HOUDINI_UTIL_SCRIPT_PATH is the path where this file is located.


sourceHoudini() {
    # Execute the script passing in any args we might want.
    ${HOUDINI_UTIL_SCRIPT_PATH}/sourceHoudini.py $@

    #  If there is no source_houdini file in /tmp then we just bail
    if [ ! -f /tmp/source_houdini ]; then
	return
    fi

    # Get the directory path from the file, store it then remove the temp file.
    export HPATH=`tail /tmp/source_houdini`
    rm /tmp/source_houdini

    # Make sure we got a path.
    if [ -z $HPATH ]; then
	return
    fi

    # Change to the install dir, source houdini_setup and then return to
    # where we were originally.
    pushd $HPATH 1>/dev/null && source houdini_setup && popd 1>/dev/null
    # Unset our install path.
    unset HPATH
}