Perl tips - creating your own utility library using classes

- Creating your own library of utility functions

• Create a file MyUtils.pm
• For each new class in it, start with package MyUtils::MyClass.
• Create static class attributes using our $attr.
• Create methods using sub meth1{ my @args = @_; ... }. If this will be used as an object method (not static), remember to treat first entry of @_ as reference to object.
• Object is nothing but a normal data type (like hash or list) and is allocated in the new method (that you must define) and returned.
  
• The new method should be like sub new {my ($class, $otherargs) = @_; my ;...; my $ref_to_somedata; bless , $class; return $ref_to_somedata;}.
• Start with package MyUtils::MyClass::MySubClass to create a subclass.
  

Accessing your library MyUtils.pm

• First include use lib "path/to/dir/containing/MyUtils.pm"; use MyUtils; in the beginning of the .pl file.
• Use MyUtils::MyClass::meth1 to access static methods.
• Use $MyUtils::MyClass::attr to access static attribute $attr of the class (note the $).
• Use MyUtils::MyClass->new(...) to create an object.
• Use MyUtils::MyClass::MySubClass wherever you are using MyUtils::MyClass for subclasses.
  

Other useful stuff

• Use $ENV{env_variable} to access the value of environment variable $env_variable in Perl code, (useful for specifying "path/to/dir/" of .pm file).