Environment Modules (software): Difference between revisions

Revision as of 19:57, 31 July 2025

Revision as of 05:47, 7 August 2025

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The modules system is based on modulefiles,<ref>{{cite web |url=http://modules.sourceforge.net/man/modulefile.html |title=modulefile - files containing Tcl code for the Modules package |author=John L. Furlani & Peter W. Osel |date=July 2009 |website=SourceForge |publisher=man page |access-date=9 February 2014}}</ref> which specify groups of environment settings that need to be made together. Modulefiles can be installed in a central ___location for general use, or in a user directory for personal use. Environment Modules modulefiles are written in the [[Tcl]] (Tool Command Language) and are interpreted by the modulecmd program via the module<ref>{{cite web |url=http://modules.sourceforge.net/man/module.html |title=module - command interface to the Modules package |author=John L. Furlani & Peter W. Osel |date=July 2009 |website=SourceForge |publisher=man page |access-date=9 February 2014}}</ref> user interface.

The key advantage of Environment Modules is that it is shell independent and supports all major shells such as [[Bash (Unix shell)|Bash]] (bash), [[KornShell]] (ksh), [[Z shell]] (zsh), [[Fish (Unix shell)|Fish]] (fish), [[Bourne shell]] (sh), [[tcsh]], and [[C shell]] (csh). The second key advantage is that it allows to use multiple versions of the program or package from the same account by just loading proper module. Those two advantages were instrumental in making Environment Modules a part of most HPC cluster setups. It also inspired several alternative implementation such as lmod from University of Texas, which is written in [[Lua (programming language)|Lua]] instead of Tcl.

Modulefiles are created on per application per version basis. They can be dynamically loaded, unloaded, or switched. Along with the capability of using multiple versions of the same software it also can be used to implement site policies regarding the access and use of applications.