How to install package modules(manually) in activeperl

Question

I'm working on an example in perl in oops concept.I'm unable to install the perl package modules.

This file is saved with student.pm

 package Student;
 require Exporter;
 use vars qw(@ISA @EXPORT);
 @ISA = qw(Exporter);
 our @EXPORT =('new'); 
 sub new   
 {  
     my $class = shift;  
     my $self = {  
         _name => shift,  
         _rank  => shift,     
     };  

     print "Student's name is $self->{_name}\n";  
     print "Student's rank is $self->{_rank}\n";  

     bless $self, $class;  
     return $self;  
 }  

 1;

This file is saves with person.pl

  use Student; 
  $object = new Student( "Ram", "3th");

I'm getting error message like this Can't locate Student.pm in @INC (you may need to install the Student module) (@INC contains: C:/Perl64/site/lib C:/Perl64/lib)........

Try include the current directory in the module search path: `use lib '.'`. See also [Doesn't Perl include current directory in @INC by default?](https://stackoverflow.com/q/46549671/2173773) — Håkon Hægland, Jun 18 '19 at 14:08
@HåkonHægland: You should expand that into an answer. I bet it's the correct solution. — Dave Cross, Jun 18 '19 at 16:16
@Håkon Hægland, You should read the page you linked, seeing as it explains that `use lib '.';` is wrong. — ikegami, Jun 18 '19 at 19:43

score 2 · Accepted Answer · edited Jun 18 '19 at 19:42

2

To load a module in the current directory, add the current directory to the module search path @INC:

use strict;
use warnings;
use FindBin qw( $RealBin );  # The script's directory.
use lib $RealBin;            # Look for modules there.
use Student; 
my $object = Student->new( "Ram", "3th");

Also note that the module name should be Student.pm and not student.pm. Case is significant.

 package Student;
 use Exporter qw(import);
 our @EXPORT = qw(); 
 sub new   {  
     my $class = shift;  
     my $self = {  
         _name => shift,  
         _rank  => shift,     
     };  

     print "Student's name is $self->{_name}\n";  
     print "Student's rank is $self->{_rank}\n";  

     bless $self, $class;  
     return $self;  
 }  

 1;

NOTES:

new Student is the old way of instantiating an object (using so-called indirect object notation). The recommended way is now Student->new(...)
our @EXPORT =('new'): You do not need to export new and it is usually a mistake to do so. Since object creation should be qualified by the module name, it does not make sense to export new.
require Exporter; use vars qw(@ISA @EXPORT); @ISA = qw(Exporter); is old style. Better to write use Exporter qw(import).

edited Jun 18 '19 at 19:42

ikegami

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answered Jun 18 '19 at 16:40

Håkon Hægland

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2

Re "*Case is significant.*", Technically, `use Student;` + `package Student;` + 'student.pm` will work on a case-insensitive file system. But I agree that the file *should* be named `Student.pm` even if it's not required. – ikegami Jun 18 '19 at 19:41
If both files are in different directories, is there any changes to be made from the above program. – Ekanvitha Jun 20 '19 at 10:04
@Ekanvitha Yes if for example `Student.pm` is in directory `lib` relative to `person.pl` you need `use lib "${RealBin}/lib"` – Håkon Hægland Jun 20 '19 at 10:07
I have saved student.pm in D:\Ekanvitha\modules and Student.pl in D:\Ekanvitha\perl. I have added like this use lib " ${RealBin}\Ekanvitha\modules"; error is displaying as Useless use of \E at D:\Ekanvitha\perl\student.pl line 6. Unrecognized escape \m passed through at D:\Ekanvitha\perl\student.pl line 6. Global symbol "$RealBin" requires explicit package name (did you forget to declare "my $RealBin"?) at D:\Ekanvitha\perl\student.pl line 6. BEGIN not safe after errors--compilation aborted at D:\Ekanvitha\perl\student.pl line 6. – Ekanvitha Jun 20 '19 at 11:14
@Ekanvitha If you use backslashes in the path, you would need to escape them. Alternatively, you could try `use lib ($RealBin . '\..\modules');` since single quotes do not interpret backslash escape sequences – Håkon Hægland Jun 20 '19 at 11:34
I'm facing this error -Global symbol "$RealBin" requires explicit package name (did you forget to declare "my $RealBin"?) at D:\Ekanvitha\perl\student.pl line 6. BEGIN not safe after errors--compilation aborted at D:\Ekanvitha\perl\student.pl line 6. – Ekanvitha Jun 20 '19 at 11:51
@Ekanvitha Could you send me the code you are working on? Then I will have a look at it. You can find my email in my profile. – Håkon Hægland Jun 20 '19 at 11:55

How to install package modules(manually) in activeperl

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