Provided by: environment-modules_4.1.1-1_amd64 
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. If a
version number doesn't exist, then modulecmd.tcl will assume the modulefile is compatible
with the latest version. The current modulefile version is 1.0. Files without the magic
cookie will not be interpreted by modulecmd.tcl.
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 modulefiles is a simple bit of code that set or add entries to the PATH,
MANPATH, or other environment variables. Tcl has conditional statements that are evaluated
when the modulefile is loaded. 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.
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.
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.
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.)
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.
append-path [-d C|--delim C|--delim=C] [--duplicates] variable value...
See prepend-path.
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.
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. Elsewhere 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.
prereq modulefile...
See conflict.
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.
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.
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.
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.
module [sub-command] [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.
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 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 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 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 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 specified
Return the name of the modulefile specified on the command line.
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 elsewhere. 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 elsewhere. shelltypename can be: sh, csh, fish, tcl, perl,
python, ruby, lisp, cmake, r.
module-info alias name
Returns the full modulefile name to which the modulefile alias name is assigned
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-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 loaded modulefile
Returns the names of currently loaded modules matching passed modulefile. The
parameter modulefile might either be a full qualified modulefile with name and
version or just a directory which in case all loaded modulefiles from the directory
will be returned.
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 '.' 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-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-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).
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.
unset-alias alias-name
Unsets an alias with the name alias-name in the user's environment.
system string
Pass string to the Tcl built-in command exec(n). For the exec(n) call 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 tclvars(n) man page). Uname will return the string "unknown" if
information is unavailable for the field.
uname will invoke 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
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
The ModulesCurrentModulefile variable contains the full pathname of the modulefile being
interpreted.
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 is 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 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 the
directory. This will become the default modulefile in this case.
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 Tcl interpreted. 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, 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 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.
A modulefile whose name or element in its name starts with a '.' dot is considered hidden.
Hidden modulefile is not displayed or taken into account except if it is explicitly named.
By inheritance, a symbolic version-name assigned to a hidden modulefile is displayed or
taken into account only if explicitly named. Module alias targeting a hidden modulefile
appears like any other module alias.
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
MODULEPATH
Path of directories containing modulefiles.
SEE ALSO
module(1), Tcl(n), TclX(n), 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, 2016-2018 Xavier Delaruelle