Package Initialization¶

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 snapshot 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, perl, and cmake "shells" are supported, which writes the environment changes to stdout as python, perl, or cmake code.

The perl module command is set up with:

use lib $ENV{'MODULESHOME'}."/init";
use perl;

And the python module command is defined with:

import os, sys;
sys.path.insert(0, '@INITPATH@')

from python import module;

Modulecmd startup¶

Upon invocation modulecmd sources rc files which contain global, user and modulefile specific setups. These files are interpreted as modulefiles. See modulefile(4) 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.

Command line switches¶

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

Module Sub-Commands¶

Modulefiles¶

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.