perl function endgrent

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

use POSIX qw(getgrgid endgrent);

my $gid = 1000;
my $group;

while (my $g = getgrent()) {
  if ($g->gid == $gid) {
    $group = $g->name;
    last;
  }
}

endgrent();

print "Group for GID $gid: $group\n";

In this example, the getgrent function is used in a loop to iterate over each entry in the system's group file. For each group entry, the script checks if its GID matches the value of $gid. If a matching group is found, its name is stored in the $group variable and the loop is exited using the last keyword.

After the loop has finished, the endgrent function is called to free system resources associated with the group file. Finally, the script prints the name of the group corresponding to the GID specified by $gid.

The endgrent function is typically used after calling getgrent, getgrgid, or getgrnam to ensure that system resources are properly freed. If you forget to call endgrent, it may cause resource leaks or other issues.