The modules tool (http://modules.sourceforge.net/) is used to manage software on the Redhawk cluster.  Modules works by adding or updating Linux environment variables to add parameters needed for a specific software package.  The module file for a particular tool can also load other module files that are required for a particular tool.

A default set of modules are automatically loaded for all users.  On the Redhawk cluster, module files are named using the name of a software package and version information if multiple versions are installed.  Often, a generic module file will be created as a link to a specific version.  For example, the module file for “matlab” is linked to a specific version, and will be updated as newer versions are installed.

Module commands take the form of the word “module” followed by a specific module command, and when needed, the name of a module file.

Some frequently used module commands are:

• module list – this shows all currently loaded module files.
• module avail – list all currently available module files
• module load <module-file> – load a specific module file
• module unload <module-file> – unload a specific module file
• module whatis- provides info about a specific module file.  This should include version info (where available).
• module swap <module-file1> <module-file2> – unloads module-file1 and loads module-file2.
• module initadd- add a specific module file to the set of modules loaded when you login.  This takes effect the next time you login.
• module initrm- remove a module file from the set loaded when you login.  Note that you can only remove module you loaded with the module initadd command, you cannot remove modules loaded at the system level.