perl function local

In Perl, the local function is used to create a new value for a global variable that is local to the current block or subroutine. This means that any changes made to the variable within the scope of the local declaration will only affect that scope, and the original value of the global variable will be restored when the scope is exited.

Here's an example that demonstrates how to use local:

#!/usr/bin/perl

use strict;
use warnings;

# Define a global variable
my $global_var = "foo";

# Print the original value of the global variable
print "Original value of global_var: $global_var\n";

# Define a new value for the global variable within a local scope
{
    local $global_var = "bar";
    # Print the new value of the global variable
    print "New value of global_var: $global_var\n";
}

# Print the original value of the global variable again
print "Original value of global_var: $global_var\n";

In this example, we define a global variable $global_var and assign it the value "foo". We then print the original value of $global_var.

Next, we define a new value for $global_var within a local scope using the local function. We set $global_var to "bar" within this scope. We then print the new value of $global_var within the scope.

Finally, we exit the local scope and print the original value of $global_var again. This demonstrates that the original value of $global_var is restored outside of the local scope.

When we run this script, it will output the following:

Original value of global_var: foo
New value of global_var: bar
Original value of global_var: foo

As we can see, the original value of $global_var is preserved outside of the local scope, and the new value set within the local scope only affects that scope.