perl function endnetent

The endnetent function in Perl is used to free system resources associated with the network file that were previously allocated by the getnetent function. Here's an example of how to use endnetent:

use Socket;
use POSIX qw(getnetent endnetent);

my $netname = 'loopback';
my $netaddr;

while (my ($name, $net, $host, $mask, $snum, $enum) = getnetent()) {
  if ($name eq $netname) {
    $netaddr = inet_ntoa($net);
    last;
  }
}

endnetent();

print "Address for $netname network: $netaddr\n";

In this example, the getnetent function is used in a loop to iterate over each entry in the system's network file. For each network entry, the script checks if its name matches the value of $netname. If a matching network is found, its address is converted to a string using the inet_ntoa function and stored in the $netaddr variable. The loop is then exited using the last keyword.

After the loop has finished, the endnetent function is called to free system resources associated with the network file. Finally, the script prints the address corresponding to the network specified by $netname.

The endnetent function is typically used after calling getnetent, getnetbyaddr, or getnetbyname to ensure that system resources are properly freed. If you forget to call endnetent, it may cause resource leaks or other issues.