Manpages - Module_Load_Conditional.3perl

> BOOL ] ); =check_install allows you to verify if a certain module is installed or not. You may call it with the following arguments:

module

The name of the module you wish to verify Ω- this is a required key

version

The version this module needs to be Ω- this is optional

verbose

Whether or not to be verbose about what it is doing Ω- it will default to $Module::Load::Conditional::VERBOSE

It will return undef if it was not able to find where the module was installed, or a hash reference with the following keys if it was able to find the file:

file

Full path to the file that contains the module

dir

Directory, or more exact the @INC entry, where the module was loaded from.

version

The version number of the installed module - this will be undef if the module had no (or unparsable) version number, or if the variable $Module::Load::Conditional::FIND_VERSION was set to true. (See the GLOBAL VARIABLES section below for details)

uptodate

A boolean value indicating whether or not the module was found to be at least the version you specified. If you did not specify a version, uptodate will always be true if the module was found. If no parsable version was found in the module, uptodate will also be true, since check_install had no way to verify clearly. See also $Module::Load::Conditional::DEPRECATED, which affects the outcome of this value.

[verbose > BOOL, nocache => BOOL, autoload => BOOL] ) =can_load will take a list of modules, optionally with version numbers and determine if it is able to load them. If it can load ALL of them, it will. If one or more are unloadable, none will be loaded.

This is particularly useful if you have More Than One Way (tm) to solve a problem in a program, and only wish to continue down a path if all modules could be loaded, and not load them if they couldn’t.

This function uses the load function or the autoload_remote function from Module::Load under the hood.

can_load takes the following arguments:

modules

This is a hashref of module/version pairs. The version indicates the minimum version to load. If no version is provided, any version is assumed to be good enough.

verbose

This controls whether warnings should be printed if a module failed to load. The default is to use the value of $Module::Load::Conditional::VERBOSE.

nocache

can_load keeps its results in a cache, so it will not load the same module twice, nor will it attempt to load a module that has already failed to load before. By default, can_load will check its cache, but you can override that by setting nocache to true.

autoload

This controls whether imports the functions of a loaded modules to the caller package. The default is no importing any functions. See the autoload function and the autoload_remote function from Module::Load for details.

requires can tell you what other modules a particular module requires. This is particularly useful when you’re intending to write a module for public release and are listing its prerequisites.

requires takes but one argument: the name of a module. It will then first check if it can actually load this module, and return undef if it can’t. Otherwise, it will return a list of modules and pragmas that would have been loaded on the module’s behalf.

Note: The list require returns has originated from your current perl and your current install.

This controls whether Module::Load::Conditional will issue warnings and explanations as to why certain things may have failed. If you set it to 0, Module::Load::Conditional will not output any warnings. The default is 0;

This controls whether Module::Load::Conditional will try to parse (and eval) the version from the module you’re trying to load.

If you don’t wish to do this, set this variable to false. Understand then that version comparisons are not possible, and Module::Load::Conditional can not tell you what module version you have installed. This may be desirable from a security or performance point of view. Note that $FIND_VERSION code runs safely under taint mode.

The default is 1;

This controls whether Module::Load::Conditional checks your %INC hash to see if a module is available. By default, only @INC is scanned to see if a module is physically on your filesystem, or available via an @INC-hook. Setting this variable to true will trust any entries in %INC and return them for you.

The default is 0;

This controls whether Module::Load::Conditional sanitises @INC by removing “.”. The current default setting is 0, but this may change in a future release.

This holds the cache of the can_load function. If you explicitly want to remove the current cache, you can set this variable to undef

This holds a string of the last error that happened during a call to can_load. It is useful to inspect this when can_load returns undef.

This controls whether Module::Load::Conditional checks if a dual-life core module has been deprecated. If this is set to true check_install will return false to uptodate, if a dual-life module is found to be loaded from $Config{privlibexp}

The default is 0;