MODULEFILE(4)

NAME
modulefile - files containing Tcl code for the Modules package

DESCRIPTION

modulefiles are written in the Tool Command Language, Tcl(n) and are interpreted by the modulecmd.tcl program via the module(1) user interface. modulefiles can be loaded, unloaded, or switched on-the-fly while the user is working; and can be used to implement site policies regarding the access and use of applications.

A modulefile begins with the magic cookie, #%Module. A version number may be placed after this string. The version number is useful as the modulefile format may change thus it reflects the minimum version of modulecmd.tcl required to interpret the modulefile. If a version number doesn't exist, then modulecmd.tcl will assume the modulefile is compatible. Files without the magic cookie or with a version number greater than the current version of modulecmd.tcl will not be interpreted. If the mcookie_version_check configuration is disabled the version number set is not checked.

Each modulefile contains the changes to a user's environment needed to access an application. Tcl is a simple programming language which permits modulefiles to be arbitrarily complex, depending upon the application's and the modulefile writer's needs. If support for extended tcl (tclX) has been configured for your installation of the Modules package, you may use all the extended commands provided by tclX, too.

A typical modulefile is a simple bit of code that set or add entries to the PATH, MANPATH, or other environment variables. A Modulefile is evaluated against current modulecmd.tcl's mode which leads to specific evaluation results. For instance if the modulefile sets a value to an environment variable, this variable is set when modulefile is loaded and unset when modulefile is unloaded.

Tcl has conditional statements that are evaluated when the modulefile is interpreted. This is very effective for managing path or environment changes due to different OS releases or architectures. The user environment information is encapsulated into a single modulefile kept in a central location. The same modulefile is used by every user on any machine. So, from the user's perspective, starting an application is exactly the same irrespective of the machine or platform they are on.

modulefiles also hide the notion of different types of shells. From the user's perspective, changing the environment for one shell looks exactly the same as changing the environment for another shell. This is useful for new or novice users and eliminates the need for statements such as "if you're using the C Shell do this ..., otherwise if you're using the Bourne shell do this ...". Announcing and accessing new software is uniform and independent of the user's shell. From the modulefile writer's perspective, this means one set of information will take care of every type of shell.

MODULES SPECIFIC TCL COMMANDS

The Modules Package uses commands which are extensions to the "standard" Tool Command Language Tcl(n) package. Unless otherwise specified, the Module commands return the empty string. Some commands behave differently when a modulefile is loaded or unloaded. The command descriptions assume the modulefile is being loaded.

append-path [-d C|--delim C|--delim=C] [--duplicates] variable value...
    See prepend-path.

break
    This is not a Modules-specific command, it's actually part of Tcl, which has been overloaded similar to the continue and exit commands to have the effect of causing the module not to be listed as loaded and not affect other modules being loaded concurrently. All non-environment commands within the module will be performed up to this point and processing will continue on to the next module on the command line. The break command will only have this effect if not used within a Tcl loop though.

    An example: Suppose that a full selection of modulefiles are needed for various different architectures, but some of the modulefiles are not needed and the user should be alerted. Having the unnecessary modulefile be a link to the following notavail modulefile will perform the task as required.

    #%Module1.0
    ## notavail modulefile
    ##
    proc ModulesHelp { } {
        puts stderr "This module does nothing but alert the user"
        puts stderr "that the [module-info name] module is not available"
    }
    module-whatis "Notifies user that module is not available."
    set curMod [module-info name]
    if { [ module-info mode load ] } {
        puts stderr "Note: '$curMod' is not available for [uname sysname]."
    }
    break

chdir directory
    Set the current working directory to directory.

conflict modulefile...
    prereq and conflict control whether or not the modulefile will be loaded. The prereq command lists modulefiles which must have been previously loaded before the current modulefile will be loaded. Similarly, the conflict command lists modulefiles which conflict with the current modulefile. If a list contains more than one modulefile, then each member of the list acts as a Boolean OR operation. Multiple prereq and conflict commands may be used to create a Boolean AND operation. If one of the requirements have not been satisfied, an error is reported and the current modulefile makes no changes to the user's environment.

    If an argument for prereq is a directory and any modulefile from the directory has been loaded, then the prerequisite is met. For example, specifying X11 as a prereq means that any version of X11, X11/R4 or X11/R5, must be loaded before proceeding.

    If an argument for conflict is a directory and any other modulefile from that directory has been loaded, then a conflict will occur. For example, specifying X11 as a conflict will stop X11/R4 and X11/R5 from being loaded at the same time.

    The parameter modulefile may also be a symbolic modulefile name or a modulefile alias. It may also leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

continue
    This is not a modules specific command but another overloaded Tcl command and is similar to the break or exit commands except the module will be listed as loaded as well as performing any environment or Tcl commands up to this point and then continuing on to the next module on the command line. The continue command will only have this effect if not used within a Tcl loop though.

exit [N]
    This is not a modules specific command but another overloaded Tcl command and is similar to the break or continue commands. However, this command will cause the immediate cessation of this module and any additional ones on the command line. This module and the subsequent modules will not be listed as loaded. No environment commands will be performed in the current module.

getenv variable [value]
    Returns value of environment variable. If variable is not defined, value is returned if set, _UNDEFINED_ is returned otherwise. The getenv command should be preferred over the Tcl global variable env to query environment variables.

is-avail modulefile...
    The is-avail command returns a true value if any of the listed modulefiles exists in enabled MODULEPATH. If a list contains more than one modulefile, then each member acts as a boolean OR operation. If an argument for is-avail is a directory and a modulefile exists in the directory is-avail would return a true value.

    The parameter modulefile may also be a symbolic modulefile name or a modulefile alias. It may also leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

is-loaded [modulefile...]
    The is-loaded command returns a true value if any of the listed modulefiles has been loaded or if any modulefile is loaded in case no argument is provided. If a list contains more than one modulefile, then each member acts as a boolean OR operation. If an argument for is-loaded is a directory and any modulefile from the directory has been loaded is-loaded would return a true value.

    The parameter modulefile may also be a symbolic modulefile name or a modulefile alias. It may also leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

is-saved [collection...]
    The is-saved command returns a true value if any of the listed collections exists or if any collection exists in case no argument is provided. If a list contains more than one collection, then each member acts as a boolean OR operation.

    If MODULES_COLLECTION_TARGET is set, a suffix equivalent to the value of this variable is appended to the passed collection name. In case no collection argument is provided, a true value will only be returned if a collection matching currently set target exists.

is-used [directory...]
    The is-used command returns a true value if any of the listed directories has been enabled in MODULEPATH or if any directory is enabled in case no argument is provided. If a list contains more than one directory, then each member acts as a boolean OR operation.

module [sub-command] [sub-command-options] [sub-command-args]
    Contains the same sub-commands as described in the module(1) man page in the Module Sub-Commands section. This command permits a modulefile to load or unload other modulefiles. No checks are made to ensure that the modulefile does not try to load itself. Often it is useful to have a single modulefile that performs a number of module load commands. For example, if every user on the system requires a basic set of applications loaded, then a core modulefile would contain the necessary module load commands.

    The --not-req option may be set for the load, unload and switch sub-commands to inhibit the definition of an implicit prereq or conflict requirement onto specified modules.

    Command line switches --auto, --no-auto and --force are ignored when passed to a module command set in a modulefile.

module-alias name modulefile
    Assigns the modulefile to the alias name. This command should be placed in one of the modulecmd.tcl rc files in order to provide shorthand invocations of frequently used modulefile names.

    The parameter modulefile may be either

•   a fully qualified modulefile with name and version

•   a symbolic modulefile name

•   another modulefile alias

module-forbid [options] modulefile...
    Forbid use of modulefile. An error is obtained when trying to evaluate a forbidden module. This command should be placed in one of the modulecmd.tcl rc files.

    module-forbid command accepts the following options:

•   --after datetime

•   --before datetime

•   --not-user {user...}

•   --not-group {group...}

•   --message {text message}

•   --nearly-message {text message}

    If --after option is set, forbidding is only effective after specified date time. Following the same principle, if --before option is set, forbidding is only effective before specified date time. Accepted date time format is YYYY-MM-DD[THH:MM]. If no time (HH:MM) is specified, 00:00 is assumed. --after and --before options are not supported on Tcl versions prior to 8.5.

    If --not-user option is set, forbidding is not applied if the username of the user currently running modulecmd.tcl is part of the list of username specified. Following the same approach, if --not-group option is set, forbidding is not applied if current user is member of one the group specified. When both options are set, forbidding is not applied if a match is found for --not-user or --not-group.

    Error message returned when trying to evaluate a forbidden module can be supplemented with the text message set through --message option.

    If --after option is set, modules are considered nearly forbidden during a number of days defined by the nearly_forbidden_days modulecmd.tcl configuration option (see MODULES_NEARLY_FORBIDDEN_DAYS), prior reaching the expiry date fixed by --after option. When a nearly forbidden module is evaluated a warning message is issued to inform module will soon be forbidden. This warning message can be supplemented with the text message set through --nearly-message option.

    If a module-forbid command applies to a modulefile also targeted by a module-hide --hard command, this module is unveiled when precisely named to return an access error.

    Forbidden modules included in the result of an avail sub-command are reported with a forbidden tag applied to them. Nearly forbidden modules included in the result of an avail or a list sub-command are reported with a nearly-forbidden tag applied to them. See Module tags section in module(1).

    The parameter modulefile may leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

module-hide [options] modulefile...
    Hide modulefile to exclude it from available module search or module selection unless query refers to modulefile by its exact name. This command should be placed in one of the modulecmd.tcl rc files.

    module-hide command accepts the following options:

•   --soft|--hard

•   --hidden-loaded

•   --after datetime

•   --before datetime

•   --not-user {user...}

•   --not-group {group...}

    When --soft option is set, modulefile is also set hidden, but hiding is disabled when search or selection query's root name matches module's root name. This soft hiding mode enables to hide modulefiles from bare module availability listing yet keeping the ability to select such module for load with the regular resolution mechanism (i.e., no need to use module exact name to select it)

    When --hard option is set, modulefile is also set hidden and stays hidden even if search or selection query refers to modulefile by its exact name.

    When --hidden-loaded option is set, hidden state also applies to the modulefile when it is loaded. Hidden loaded modules do not appear on list sub-command output, unless --all option is set. Their loading or unloading informational messages are not reported unless the verbosity of Modules is set to a level higher than verbose. Hidden loaded modules are detected in any cases by state query commands like is-loaded.

    If --after option is set, hiding is only effective after specified date time. Following the same principle, if --before option is set, hiding is only effective before specified date time. Accepted date time format is YYYY-MM-DD[THH:MM]. If no time (HH:MM) is specified, 00:00 is assumed. --after and --before options are not supported on Tcl versions prior to 8.5.

    If --not-user option is set, hiding is not applied if the username of the user currently running modulecmd.tcl is part of the list of username specified. Following the same approach, if --not-group option is set, hiding is not applied if current user is member of one the group specified. When both options are set, hiding is not applied if a match is found for --not-user or --not-group.

    If the --all option is set on avail, aliases, whatis or search sub-commands, hiding is disabled thus hidden modulefiles are included in module search. Hard-hidden modules (i.e., declared hidden with --hard option) are not affected by --all and stay hidden even if option is set. --all option does not apply to module selection sub-commands like load. Thus in such context a hidden module should always be referred by its exact full name (e.g., foo/1.2.3 not foo) unless if it has been hidden in --soft mode. A hard-hidden module cannot be unveiled or selected in any case.

    If several module-hide commands target the same modulefile, the strongest hiding level is retained which means if both a regular, a --soft hiding command match a given module, regular hiding mode is considered. If both a regular and a --hard hiding command match a given module, hard hiding mode is retained. A set --hidden-loaded option is retained even if the module-hide statement on which it is declared is superseded by a stronger module-hide statement with no --hidden-loaded option set.

    Hidden modules included in the result of an avail sub-command are reported with a hidden tag applied to them. Hidden loaded modules included in the result of a list sub-command are reported with a hidden-loaded tag applied to them. This tag is not reported on avail sub-command context. See Module tags section in module(1).

    The parameter modulefile may also be a symbolic modulefile name or a modulefile alias. It may also leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

module-info option [info-args]
    Provide information about the modulecmd.tcl program's state. Some of the information is specific to the internals of modulecmd.tcl. option is the type of information to be provided, and info-args are any arguments needed.

    module-info alias name Returns the full modulefile name to which the modulefile alias name is assigned

    module-info command [commandname] Returns the currently running modulecmd.tcl's command as a string if no commandname is given.

    Returns 1 if modulecmd.tcl's command is commandname. commandname can be: load, unload, reload, source, switch, display, avail, aliases, list, whatis, search, purge, restore, help or test.

    module-info loaded modulefile Returns the names of currently loaded modules matching passed modulefile. The parameter modulefile might either be a fully qualified modulefile with name and version or just a directory which in case all loaded modulefiles from the directory will be returned. The parameter modulefile may also be a symbolic modulefile name or a modulefile alias.

    module-info mode [modetype] Returns the current modulecmd.tcl's mode as a string if no modetype is given.

    Returns 1 if modulecmd.tcl's mode is modetype. modetype can be: load, unload, remove, switch, display, help, test or whatis.

    module-info name Return the name of the modulefile. This is not the full pathname for modulefile. See the Modules Variables section for information on the full pathname.

    module-info shell [shellname] Return the current shell under which modulecmd.tcl was invoked if no shellname is given. The current shell is the first parameter of modulecmd.tcl, which is normally hidden by the module alias.

    If a shellname is given, returns 1 if modulecmd.tcl's current shell is shellname, returns 0 otherwise. shellname can be: sh, bash, ksh, zsh, csh, tcsh, fish, tcl, perl, python, ruby, lisp, cmake, r.

    module-info shelltype [shelltypename] Return the family of the shell under which modulefile was invoked if no shelltypename is given. As of module-info shell this depends on the first parameter of modulecmd.tcl. The output reflects a shell type determining the shell syntax of the commands produced by modulecmd.tcl.

    If a shelltypename is given, returns 1 if modulecmd.tcl's current shell type is shelltypename, returns 0 otherwise. shelltypename can be: sh, csh, fish, tcl, perl, python, ruby, lisp, cmake, r.

    module-info specified Return the name of the modulefile specified on the command line.

    module-info symbols modulefile Returns a list of all symbolic versions assigned to the passed modulefile. The parameter modulefile might either be a full qualified modulefile with name and version, another symbolic modulefile name or a modulefile alias.

    module-info tags [tag] Returns all tags assigned to currently evaluated modulefile as a list of strings if no tag name is given (see Module tags section in module(1))

    Returns 1 if one of the tags applying to currently evaluated modulefile is tag. Returns 0 otherwise.

    module-info type Returns either C or Tcl to indicate which module command is being executed, either the C version or the Tcl-only version, to allow the modulefile writer to handle any differences between the two.

    module-info usergroups [name] Returns all the groups the user currently running modulecmd.tcl is member of as a list of strings if no name is given.

    Returns 1 if one of the group current user running modulecmd.tcl is member of is name. Returns 0 otherwise.

    If the Modules Tcl extension library is disabled, the id(1) command is invoked to fetch groups of current user.

    module-info username [name] Returns the username of the user currently running modulecmd.tcl as a string if no name is given.

    Returns 1 if username of current user running modulecmd.tcl is name. Returns 0 otherwise.

    If the Modules Tcl extension library is disabled, the id(1) command is invoked to fetch username of current user.

    module-info version modulefile Returns the physical module name and version of the passed symbolic version modulefile. The parameter modulefile might either be a full qualified modulefile with name and version, another symbolic modulefile name or a modulefile alias.

module-tag [options] tag modulefile...
    Associate tag to designated modulefile. This tag information will be reported along modulefile on avail and list sub-commands (see Module tags section in module(1)). Tag information can be queried during modulefile evaluation with the module-info tags modulefile command. module-tag commands should be placed in one of the modulecmd.tcl rc files.

    module-tag command accepts the following options:

•   --not-user {user...}

•   --not-group {group...}

    If --not-user option is set, the tag is not applied if the username of the user currently running modulecmd.tcl is part of the list of username specified. Following the same approach, if --not-group option is set, the tag is not applied if current user is member of one the group specified. When both options are set, the tag is not applied if a match is found for --not-user or --not-group.

    The parameter modulefile may also be a symbolic modulefile name or a modulefile alias. It may also leverage a specific syntax to finely select module version (see Advanced module version specifiers section below).

    Tags inherited from other modulefile commands or module states cannot be set with module-tag. Otherwise an error is returned. Those special tags are: auto-loaded, forbidden, hidden, hidden-loaded, loaded and nearly-forbidden.

    When tag equals sticky or super-sticky, designated modulefile are defined Sticky modules.

module-version modulefile version-name...
    Assigns the symbolic version-name to the modulefile. This command should be placed in one of the modulecmd.tcl rc files in order to provide shorthand invocations of frequently used modulefile names.

    The special version-name default specifies the default version to be used for module commands, if no specific version is given. This replaces the definitions made in the .version file in former modulecmd.tcl releases.

    The parameter modulefile may be either

•   a fully or partially qualified modulefile with name / version. If name is . (dot) then the current directory name is assumed to be the module name. (Use this for deep modulefile directories.)

•   a symbolic modulefile name

•   another modulefile alias

module-virtual name modulefile
    Assigns the modulefile to the virtual module name. This command should be placed in rc files in order to define virtual modules.

    A virtual module stands for a module name associated to a modulefile. The modulefile is the script interpreted when loading or unloading the virtual module which appears or can be found with its virtual name.

    The parameter modulefile corresponds to the relative or absolute file location of a modulefile.

module-whatis string
    Defines a string which is displayed in case of the invocation of the module whatis command. There may be more than one module-whatis line in a modulefile. This command takes no actions in case of load, display, etc. invocations of modulecmd.tcl.

    The string parameter has to be enclosed in double-quotes if there's more than one word specified. Words are defined to be separated by whitespace characters (space, tab, cr).

prepend-path [-d C|--delim C|--delim=C] [--duplicates] variable value...
    Append or prepend value to environment variable. The variable is a colon, or delimiter, separated list such as PATH=directory:directory:directory. The default delimiter is a colon :, but an arbitrary one can be given by the --delim option. For example a space can be used instead (which will need to be handled in the Tcl specially by enclosing it in " " or { }). A space, however, can not be specified by the --delim=C form.

    A reference counter environment variable is also set to increase the number of times value has been added to environment variable. This reference counter environment variable is named by suffixing variable by _modshare.

    When value is already defined in environement variable, it is not added again except if --duplicates option is set.

    If the variable is not set, it is created. When a modulefile is unloaded, append-path and prepend-path become remove-path.

    If value corresponds to the concatenation of multiple elements separated by colon, or delimiter, character, each element is treated separately.

prereq modulefile...
    See conflict.

remove-path [-d C|--delim C|--delim=C] [--index] variable value...
    Remove value from the colon, or delimiter, separated list in variable. See prepend-path or append-path for further explanation of using an arbitrary delimiter. Every string between colons, or delimiters, in variable is compared to value. If the two match, value is removed from variable if its reference counter is equal to 1 or unknown.

    When --index option is set, value refers to an index in variable list. The string element pointed by this index is set for removal.

    Reference counter of value in variable denotes the number of times value has been added to variable. This information is stored in environment variable_modshare. When attempting to remove value from variable, relative reference counter is checked and value is removed only if counter is equal to 1 or not defined. Otherwise value is kept in variable and reference counter is decreased by 1.

    If value corresponds to the concatenation of multiple elements separated by colon, or delimiter, character, each element is treated separately.

set-alias alias-name alias-string
    Sets an alias or function with the name alias-name in the user's environment to the string alias-string. For some shells, aliases are not possible and the command has no effect. When a modulefile is unloaded, set-alias becomes unset-alias.

set-function function-name function-string
    Creates a function with the name function-name in the user's environment with the function body function-string. For some shells, functions are not possible and the command has no effect. When a modulefile is unloaded, set-function becomes unset-function.

setenv variable value
    Set environment variable to value. The setenv command will also change the process' environment. A reference using Tcl's env associative array will reference changes made with the setenv command. Changes made using Tcl's env associative array will NOT change the user's environment variable like the setenv command. An environment change made this way will only affect the module parsing process. The setenv command is also useful for changing the environment prior to the exec or system command. When a modulefile is unloaded, setenv becomes unsetenv. If the environment variable had been defined it will be overwritten while loading the modulefile. A subsequent unload will unset the environment variable - the previous value cannot be restored! (Unless you handle it explicitly ... see below.)

source-sh shell script [arg...]
    Evaluate with shell the designated script with defined arguments to find out the environment changes it does. Those changes obtained by comparing environment prior and after script evaluation are then translated into corresponding modulefile commands, which are then applied during modulefile evaluation as if they were directly written in it.

    When modulefile is unloaded, environment changes done are reserved by evaluating in the unload context the resulting modulefile commands, which were recorded in the MODULES_LMSOURCESH environment variable at load time.

    Changes on environment variables, shell aliases, shell functions and current working directory are tracked.

    Shell could be specified as a command name or a fully qualified pathname. The following shells are supported: sh, dash, csh, tcsh, bash, ksh, ksh93, zsh and fish.

system string
    Run string command through shell. On Unix, command is passed to the /bin/sh shell whereas on Windows it is passed to cmd.exe. modulecmd.tcl redirects stdout to stderr since stdout would be parsed by the evaluating shell. The exit status of the executed command is returned.

uname field
    Provide lookup of system information. Most field information are retrieved from the tcl_platform array (see the tclvars(n) man page). Uname will return the string unknown if information is unavailable for the field.

    uname will invoke the uname(1) command in order to get the operating system version and domainname(1) to figure out the name of the domain.

    field values are:

•   sysname: the operating system name

•   nodename: the hostname

•   domain: the name of the domain

•   release: the operating system release

•   version: the operating system version

•   machine: a standard name that identifies the system's hardware

unset-alias alias-name
    Unsets an alias with the name alias-name in the user's environment.

unset-function function-name
    Removes a function with the name function-name from the user's environment.

unsetenv variable [value]
    Unsets environment variable. However, if there is an optional value, then when unloading a module, it will set variable to value. The unsetenv command changes the process' environment like setenv.

versioncmp version1 version2
    Compare version string version1 against version string version2. Returns -1, 0 or 1 respectively if version1 is less than, equal to or greater than version2.

x-resource [resource-string|filename]
    Merge resources into the X11 resource database. The resources are used to control look and behavior of X11 applications. The command will attempt to read resources from filename. If the argument isn't a valid file name, then string will be interpreted as a resource. Either filename or resource-string is then passed down to be xrdb(1) command.

    modulefiles that use this command, should in most cases contain one or more x-resource lines, each defining one X11 resource. The DISPLAY environment variable should be properly set and the X11 server should be accessible. If x-resource can't manipulate the X11 resource database, the modulefile will exit with an error message.

    Examples:

    x-resource /u2/staff/leif/.xres/Ileaf The content of the Ileaf file is merged into the X11 resource database.

    x-resource [glob ~/.xres/ileaf] The Tcl glob function is used to have the modulefile read different resource files for different users.

    x-resource {Ileaf.popup.saveUnder: True} Merge the Ileaf resource into the X11 resource database.

MODULES VARIABLES

ModulesCurrentModulefile
    The ModulesCurrentModulefile variable contains the full pathname of the modulefile being interpreted.

ModuleTool
    The ModuleTool variable contains the name of the module implementation currently in use. The value of this variable is set to Modules for this implementation.

ModuleToolVersion
    The ModuleToolVersion variable contains the version of the module implementation currently in use. The value of this variable is set to 4.7.0 for this version of Modules.

LOCATING MODULEFILES

Every directory in MODULEPATH is searched to find the modulefile. A directory in MODULEPATH can have an arbitrary number of sub-directories. If the user names a modulefile to be loaded which is actually a directory, the directory is opened and a search begins for an actual modulefile. First, modulecmd.tcl looks for a file with the name .modulerc in the directory. If this file exists, its contents will be evaluated as if it was a modulefile to be loaded. You may place module-version, module-alias and module-virtual commands inside this file.

Additionally, before seeking for .modulerc files in the module directory, the global modulerc file and the .modulerc file found at the root of the modulepath directory are sourced, too. If a named version default now exists for the modulefile to be loaded, the assigned modulefile now will be sourced. Otherwise the file .version is looked up in the module directory.

If the .version file exists, it is opened and interpreted as Tcl code and takes precedence over a .modulerc file in the same directory. If the Tcl variable ModulesVersion is set by the .version file, modulecmd.tcl will use the name as if it specifies a modulefile in this directory. This will become the default modulefile in this case. ModulesVersion cannot refer to a modulefile located in a different directory.

If ModulesVersion is a directory, the search begins anew down that directory. If the name does not match any files located in the current directory, the search continues through the remaining directories in MODULEPATH.

Every .version and .modulerc file found is interpreted as Tcl code. The difference is that .version only applies to the current directory, and the .modulerc applies to the current directory and all subdirectories. Changes made in these files will affect the subsequently interpreted modulefile.

If no default version may be figured out, an implicit default is selected when this behavior is enabled (see MODULES_IMPLICIT_DEFAULT in module(1)). If disabled, module names should be fully qualified when no explicit default is defined for them, otherwise no default version is found and an error is returned. If enabled, then the highest numerically sorted modulefile, virtual module or module alias under the directory will be used. The dictionary comparison method of the lsort(n) Tcl command is used to achieve this sort. If highest numerically sorted element is an alias, search continues on its modulefile target.

For example, it is possible for a user to have a directory named X11 which simply contains a .version file specifying which version of X11 is to be loaded. Such a file would look like:

#%Module1.0
##
##  The desired version of X11
##
set ModulesVersion "R4"

The equivalent .modulerc would look like:

#%Module1.0
##
##  The desired version of X11
##
module-version "./R4" default

If the extended default mechanism is enabled (see MODULES_EXTENDED_DEFAULT in module(1)) the module version specified is matched against starting portion of existing module versions, where portion is a substring separated from the rest of version string by a . character.

When the implicit default mechanism and the Advanced module version specifiers are both enabled, a default and latest symbolic versions are automatically defined for each module name (also at each directory level in case of deep modulefile). Unless a symbolic version, alias, or regular module version already exists for these version names.

If user names a modulefile that cannot be found in the first modulepath directory, modulefile will be searched in next modulepath directory and so on until a matching modulefile is found. If search goes through a module alias or a symbolic version, this alias or symbol is resolved by first looking at the modulefiles in the modulepath where this alias or symbol is defined. If not found, resolution looks at the other modulepaths in their definition order.

When locating modulefiles, if a .modulerc, a .version, a directory or a modulefile cannot be read during the search it is simply ignored with no error message produced. Visibility of modulefiles can thus be adapted to the rights the user has been granted. Exception is made when trying to directly access a directory or a modulefile. In this case, the access issue is returned as an error message.

Depending on their name, their file permissions or the use of specific modulefile commands, modulefile, virtual module, module alias or symbolic version may be set hidden which impacts available modules search or module selection processes (see Hiding modulefiles section below).

HIDING MODULEFILES

A modulefile, virtual module, module alias or symbolic version whose name or element in their name starts with a dot character (.) or who are targeted by a module-hide command are considered hidden. Hidden modules are not displayed or taken into account except if they are explicitly named (e.g., foo/1.2.3 or foo/.2.0 not foo). If module has been hidden with the --soft option of the module-hide command set, it is not considered hidden if the root name of the query to search it matches module root name (e.g., searching foo will return a foo/1.2.3 modulefile targeted by a module-hide --soft command). If module has been hidden with the --hard option of the module-hide command set, it is always considered hidden thus it is never displayed nor taken into account even if it is explicitly named.

A modulefile, virtual module, module alias or symbolic version who are targeted by a module-hide --hard command and a module-forbid command or whose file access permissions are restricted are considered hard-hidden and forbidden. Such modules are not displayed or taken into account. When explicitly named for evaluation selection, such modules are unveiled to return an access error.

A symbolic version-name assigned to a hidden module is displayed or taken into account only if explicitly named and if module is not hard-hidden. Non-hidden module alias targeting a hidden modulefile appears like any other non-hidden module alias. Finally, a hidden symbolic version targeting a non-hidden module is displayed or taken into account only if not hard-hidden and explicitly named to refer to its non-hidden target.

The automatic version symbols (e.g., default and latest) are unaffected by hiding. Moreover when a regular default or latest version is set hidden, the corresponding automatic version symbol takes the left spot. For instance, if foo/default which targets foo/1.2.3 is set hard-hidden, the default automatic version symbol will be set onto foo/2.1.3, the highest available version of foo.

When loading a modulefile or a virtual module targeted by a module-hide --hidden-loaded command, this module inherits the hidden-loaded tag. Hidden loaded modules are not reported among list sub-command results.

If the --all is set on avail, aliases, whatis or search sub-commands, hidden modules are taken into account in search. Hard-hidden modules are unaffected by this option.

If the --all is set on list sub-command, hidden loaded modules are included in result output.

ADVANCED MODULE VERSION SPECIFIERS

When the advanced module version specifiers mechanism is enabled (see MODULES_ADVANCED_VERSION_SPEC in module(1)), the specification of modulefile passed on Modules specific Tcl commands changes. After the module name a version constraint prefixed by the @ character may be added. It could be directly appended to the module name or separated from it with a space character.

Constraints can be expressed to refine the selection of module version to:

•   a single version with the @version syntax, for instance foo@1.2.3 syntax will select module foo/1.2.3

•   a list of versions with the @version1,version2,... syntax, for instance foo@1.2.3,1.10 will match modules foo/1.2.3 and foo/1.10

•   a range of versions with the @version1:, @:version2 and @version1:version2 syntaxes, for instance foo@1.2: will select all versions of module foo greater than or equal to 1.2, foo@:1.3 will select all versions less than or equal to 1.3 and foo@1.2:1.3 matches all versions between 1.2 and 1.3 including 1.2 and 1.3 versions

    Advanced specification of single version or list of versions may benefit from the activation of the extended default mechanism (see MODULES_EXTENDED_DEFAULT in module(1)) to use an abbreviated notation like @1 to refer to more precise version numbers like 1.2.3. Range of versions on its side natively handles abbreviated versions.

    In order to be specified in a range of versions or compared to a range of versions, the version major element should corresponds to a number. For instance 10a, 1.2.3, 1.foo are versions valid for range comparison whereas default or foo.2 versions are invalid for range comparison.

    If the implicit default mechanism is also enabled (see MODULES_IMPLICIT_DEFAULT in module(1)), a default and latest symbolic versions are automatically defined for each module name (also at each directory level for deep modulefiles). These automatic version symbols are defined unless a symbolic version, alias, or regular module version already exists for these default or latest version names. Using the mod@latest (or mod/latest) syntax ensures highest available version will be selected.

MODULEFILE SPECIFIC HELP

Users can request help about a specific modulefile through the module(1) command. The modulefile can print helpful information or start help oriented programs by defining a ModulesHelp subroutine. The subroutine will be called when the module help modulefile command is used.

MODULEFILE SPECIFIC TEST

Users can request test of a specific modulefile through the module(1) command. The modulefile can perform some sanity checks on its definition or on its underlying programs by defining a ModulesTest subroutine. The subroutine will be called when the module test modulefile command is used. The subroutine should return 1 in case of success. If no or any other value is returned, test is considered failed.

MODULEFILE DISPLAY

The module display modulefile command will detail all changes that will be made to the environment. After displaying all of the environment changes modulecmd.tcl will call the ModulesDisplay subroutine. The ModulesDisplay subroutine is a good place to put additional descriptive information about the modulefile.

ENVIRONMENT

See the ENVIRONMENT section in the module(1) man page.

SEE ALSO

module(1), ml(1), Tcl(n), TclX(n), id(1), xrdb(1), exec(n), uname(1), domainname(1), tclvars(n), lsort(n)

NOTES

Tcl was developed by John Ousterhout at the University of California at Berkeley.

TclX was developed by Karl Lehenbauer and Mark Diekhans.

COPYRIGHT
1996-1999 John L. Furlani & Peter W. Osel, 1998-2017 R.K.Owen, 2002-2004 Mark Lakata, 2004-2017 Kent Mein, 2016-2021 Xavier Delaruelle