What is export in Perl?
Export allows to export the functions and variables of modules to user’s namespace using the standard import method. @EXPORT contains list of symbols (subroutines and variables) of the module to be exported into the caller namespace. @EXPORT_OK does export of symbols on demand basis.
How do I export a variable in Perl?
For a module to export one or more identifiers into a caller’s namespace, it must: use the Exporter module, which is part of the standard Perl distribution, declare the module to inherit Exporter’s capabilities, by setting the variable @ISA (see Section 7.3. 1) to equal (‘Exporter’), and.
How do I import a package into Perl?
Perl import Function
- Description. This function is an ordinary method (subroutine) defined (or inherited) by modules that wish to export names to another module.
- Syntax. Following is the simple syntax for this function − import LIST.
- Return Value. This function does not return any value.
- Example.
What is difference between use and require in Perl?
use is evaluated at compile-time, require at run-time. use implicitly calls the import method of the module being loaded, require does not. use excepts arguments in addition to the bareword (to be passed to import), require does not.
What is Isa in Perl?
A Class is Simply a Package Each package contains a special array called @ISA . The @ISA array contains a list of that class’s parent classes, if any. This array is examined when Perl does method resolution, which we will cover later. It is possible to manually set @ISA , and you may see this in older Perl code.
What is the difference between export and Export_ok?
The difference is really a matter of who controls what gets into the use r’s namespace: if you use @EXPORT then the module being use d does, if you use @EXPORT_OK then the code doing the import controls their own namespace.
What is use lib in Perl?
It is typically used to add extra directories to Perl’s search path so that later do, require, and use statements will find library files that aren’t located in Perl’s default search path. Parameters to use lib are prepended to the beginning of Perl’s search path.
What is inheritance in Perl?
Inheritance simply means that properties and methods of a parent class will be available to the child classes. Perl searches the class of the specified object for the given method or attribute, i.e., variable. Perl searches the classes defined in the object class’s @ISA array.