Modifying a hash in some other file

[mehj123]

Hi friends,

Please clear my doubt. Suppose we have a hash variable in a file, and we are accessing the same hash and adding some more keys to the hash in some other script. Will this change be reflected in the first file? Is there a way to do this so that change is reflected without deleting the old file and creating the file again with the new value?

Thanks
Mehjabeen

[KevinADC]

if the hash variable is in a file, and a script changes the file, all other scripts that access that file will see the change. You would need to use a seperate file for each script if you want to change the actual file and not have the change seen by other scripts.

[mehj123]

if the hash variable is in a file, and a script changes the file, all other scripts that access that file will see the change. You would need to use a seperate file for each script if you want to change the actual file and not have the change seen by other scripts.

Thanks for the reply... But I am unable to get the changes. This is what I am trying to do

#!/usr/bin/perl
use strict;
use warnings;
require myfile.pl
%main::my_hash=(1=>"one",2=>"two");
foreach (keys %main::my_hash)
{
print "$_\t$main::my_hash{$_}\n";
}

and myfile.pl contains

%my_hash = ();
1;

The script prints the key value pairs. But the hash value is not being updated in the myfile.pl file. Or am I doing it wrongly??

Thanks
Mehjabeen

[KevinADC]

Thanks for the reply... But I am unable to get the changes. This is what I am trying to do

#!/usr/bin/perl
use strict;
use warnings;
require myfile.pl
%main::my_hash=(1=>"one",2=>"two");
foreach (keys %main::my_hash)
{
print "$_\t$main::my_hash{$_}\n";
}

and myfile.pl contains

%my_hash = ();
1;

The script prints the key value pairs. But the hash value is not being updated in the myfile.pl file. Or am I doing it wrongly??

Thanks
Mehjabeen

The way you are doing it only changes the hash that is stored in memory when the program runs, you are not writing/changing anything in the actual file (myfile.pl). For that to work you would need to use a database module, like AnyDBM_File and perls tie() function. But really, that is not done much in perl programs anymore, most people prefer to use a databse like MySQL. So to answer your last question, yes, you are doing it wrong(ly).

[mehj123]

The way you are doing it only changes the hash that is stored in memory when the program runs, you are not writing/changing anything in the actual file (myfile.pl). For that to work you would need to use a database module, like AnyDBM_File and perls tie() function. But really, that is not done much in perl programs anymore, most people prefer to use a databse like MySQL. So to answer your last question, yes, you are doing it wrong(ly).

Thanks a lot for your reply.... :)