module is a user interface to the Modules package. The Modules package provides for the dynamic modification of the user's environment via modulefiles.

Each modulefile contains the information needed to configure the shell for an application. Once the Modules package is initialized, the environment can be modified on a per-module basis using the module command which interprets modulefiles. Typically modulefiles instruct the module command to alter or set shell environment variables such as PATH, MANPATH, etc. modulefiles may be shared by many users on a system and users may have their own collection to supplement or replace the shared modulefiles.

The modulefiles are added to and removed from the current environment by the user. The environment changes contained in a modulefile can be summarized through the module command as well. If no arguments are given, a summary of the module usage and sub-commands are shown.

The action for the module command to take is described by the sub-command and its associated arguments.

The Modules package and the module command are initialized when a shell-specific initialization script is sourced into the shell. The script creates the module command, either as an alias or shell function, creates Modules environment variables, and if enabled to do so, a snapshow of the environment is saved as either (if BEGINENV=1) $HOME/.modulesbeginenv or (if BEGINENV=99) whatever $MODULESBEGINENV points to.

The module alias or function executes the modulecmd program and has the shell evaluate the command's output. The first argument to modulecmd specifies the type of shell.

The initialization scripts are kept in $MODULESHOME/init/<shell> where <shell> is the name of the sourcing shell. The sh, csh, tcsh, bash, ksh, and zsh shells are supported by modulecmd. In addition, python and perl "shells" are supported, which writes the environment changes to stdout as python or perl code.

Upon invocation modulecmd sources rc files which contain global, user and modulefile specific setups. These files are interpreted as modulefiles. See for detailed information.

Upon invocation of modulecmd module RC files are sourced in the following order:

        Global RC file as specified by ${MODULERCFILE} or
            ${MODULESHOME}/etc/rc

        User specific module RC file ${HOME}/.modulerc

        All .modulerc and .version files found during modulefile
            seeking.

The module command accepts command line switches as its first parameter. These may be used to control output format of all information displayed and the module behavior in case of locating and interpreting module files.

All switches may be entered either in short or long notation. The following switches are accepted:

--help, -H

Give some helpful usage information, and terminates the command.

--version, -V

Lists the current version of the module command, and some configured option values. The command then terminates without further processing.

--force, -f

Force active dependency resolution. This will result in modules found on a prereq command inside a module file being load automatically. Unloading module files using this switch will result in all required modules which have been loaded automatically using the -f switch being unload. This switch is experimental at the moment.

--terse, -t

Display avail and list output in short format.

--long, -l

Display avail and list output in long format.

--human, -h

Display short output of the avail and list commands in human readable format.

--verbose, -v

Enable verbose messages during module command execution.

--silent, -s

Disable verbose messages. Redirect stderr to /dev/null if stderr is found not to be a tty. This is a useful option for module commands being written into .cshrc, .login or .profile files, because some remote shells (as rsh(1)) and remote execution commands (like rdist) get confused if there is output on stderr.

--create, -c

Create caches for module avail and module apropos. You must be granted write access to the ${MODULEHOME}/modulefiles/ directory if you try to invoke module with the -c option.

--icase, -i

Case insensitive module parameter evaluation. Currently only implemented for the module apropos command.

--userlvl <lvl>, -u <lvl>

Set the user level to the specified value. The argument of this option may be one of:

novice, nov Novice

expert, exp Experienced module user

advanced, adv Advanced module user

help [modulefile...]

Print the usage of each sub-command. If an argument is given, print the Module specific help information for the modulefile.

load modulefile [modulefile...]

add modulefile [modulefile...]

Load modulefile into the shell environment.

unload modulefile [modulefile...]

rm modulefile [modulefile...]

Remove modulefile from the shell environment.

switch [ modulefile1 ] modulefile2

swap [ modulefile1 ] modulefile2

Switch loaded modulefile1 with modulefile2. If modulefile1 is not specified, then it is assumed to be the currently loaded module with the same root name as modulefile2.

display modulefile [modulefile...]

show modulefile [modulefile...]

Display information about a modulefile. The display sub-command will list the full path of the modulefile and all (or most) of the environment changes the modulefile will make if loaded. (It will not display any environment changes found within conditional statements.)

list

List loaded modules.

avail [path...]

List all available modulefiles in the current MODULEPATH. All directories in the MODULEPATH are recursively searched for files containing the modulefile magic cookie. If an argument is given, then each directory in the MODULEPATH is searched for modulefiles whose pathname match the argument. Multiple versions of an application can be supported by creating a subdirectory for the application containing modulefiles for each version.

use directory [directory...]

use [-a|--append] directory [directory...]

Prepend directory to the MODULEPATH environment variable. The --append flag will append the directory to MODULEPATH.

unuse directory [directory...]

Remove directory from the MODULEPATH environment variable.

update

Attempt to reload all loaded modulefiles. The environment will be reconfigured to match the environment saved in ${HOME}/.modulesbeginenv (if BEGINENV=1) or the file pointed at by $MODULESBEGINEV (if BEGINENV=99) and the modulefiles will be reloaded.

This is only valid if modules was configured with --enable-beginenv (which defines BEGINENV) else this will cause a warning. update will only change the environment variables that the modulefiles set.

clear

Force the Modules Package to believe that no modules are currently loaded.

purge

Unload all loaded modulefiles.

refresh

Force a refresh of all non-persistent components of currently loaded modules. This should be used on derived shells where aliases need to be reinitialized but the environment variables have already been set by the currently loaded modules.

whatis [modulefile [modulefile...]]

Display the modulefile information set up by the module-whatis commands inside the specified modulefiles. If no modulefiles are specified all whatis information lines will be shown.

apropos string

keyword string

Seeks thru the whatis informations of all modulefiles for the specified string. All module whatis informations matching the string search will be displayed.

initadd modulefile [modulefile...]

Add modulefile to the shell's initialization file in the user's home directory. The startup files checked (in order) are: csh - .modules, .cshrc(.ext), .csh_variables, and .login(.ext) tcsh - .modules, .tcshrc, .cshrc(.ext), .csh_variables, and .login(.ext) sh and ksh - .modules, .profile(.ext), and .kshenv(.ext) bash - .modules, .bash_profile, .bash_login, .profile(.ext), and .bashrc(.ext) zsh - .modules, .zcshrc(.ext), .zshenv(.ext), and .zlogin(.ext)

If a 'module load' line is found in any of these files, the modulefile(s) is(are) appended to any existing list of modulefiles. The 'module load' line must be located in at least one of the files listed above for any of the 'init' sub-commands to work properly. If the 'module load' line is found in multiple shell initialization files, all of the lines are changed.

initprepend modulefile [modulefile...]

Does the same as initadd but prepends the given modules to the beginning of the list.

initrm modulefile [modulefile...]

Remove modulefile from the shell's initialization files.

initswitch modulefile1 modulefile2

Switch modulefile1 with modulefile2 in the shell's initialization files.

initlist

List all of the modulefiles loaded from the shell's initialization file.

initclear

Clear all of the modulefiles from the shell's initialization files.

modulefiles are written in the Tool Command Language (Tcl) and are interpreted by modulecmd. modulefiles can use conditional statements. Thus the effect a modulefile will have on the environment may change depending upon the current state of the environment.

Environment variables are unset when unloading a modulefile. Thus, it is possible to load a modulefile and then unload it without having the environment variables return to their prior state.

MODULESHOME

The location of the master Modules package file directory containing module command initialization scripts, the executable program modulecmd, and a directory containing a collection of master modulefiles.

MODULEPATH

The path that the module command searches when looking for modulefiles. Typically, it is set to a default value by the bootstrap procedure. MODULEPATH can be set using 'module use' or by the module initialization script to search group or personal modulefile directories before or after the master modulefile directory.

LOADEDMODULES

A colon separated list of all loaded modulefiles.

_LMFILES_

A colon separated list of the full pathname for all loaded modulefiles.

MODULESBEGINENV

If modules has been configured (BEGINENV=99) to test for this environment variable, then if it exists, it is the name of the file to store the the initial shell environment. This environment variable will have embedded environment variables unrolled to one level. The contents of this variable is only used the first time modules is invoked.

_MODULESBEGINENV_

The filename of the file containing the initialization environment snapshot.

/usr/share/Modules

The MODULESHOME directory.

${MODULESHOME}/etc/rc

The system-wide modules rc file. The location of this file can be changed using the MODULERCFILE environment variable as described above.

${HOME}/.modulerc

The user specific modules rc file.

${MODULESHOME}/modulefiles

The directory for system-wide modulefiles. The location of the directory can be changed using the MODULEPATH environment variable as described above.

${MODULESHOME}/bin/modulecmd

The modulefile interpreter that gets executed upon each invocation of module.

${MODULESHOME}/init/<shell>

The Modules package initialization file sourced into the user's environment.

${MODULEPATH}/.moduleavailcache

File containing the cached list of all modulefiles for each directory in the MODULEPATH (only when the avail cache is enabled via the configure option --enable-cache which sets CACHE_AVAIL).

${MODULEPATH}/.moduleavailcachedir

File containing the names and modification times for all sub-directories with an avail cache (see above).

${HOME}/.modulesbeginenv

A snapshot of the user's environment taken at Module initialization. This information is used by the module update sub-command (if BEGINENV=1), else

$MODULESBEGINENV

If this defines a valid filename, this serves the same purpose as above (if BEGINENV=99).