number of users logged in using multiple terminals

[divyashree]

I want to count the number of users who have logged in multiple terminals ?
How will I get this ?

I always get the total number of users. How will I get the uniq number of users with multiple logins ?

[Schmidt]

`users` -  print the user names of users currently logged in to the current host

[divyashree]

`users` -  print the user names of users currently logged in to the current host

No I want to count the number users whose names are repeated only.

[Schmidt]

It's also quite simple I suppose. That's a useful command, which could be used in a script:

$  who | grep $WANTED_USERNAME | awk '{print $2; }'

would show you all terminals on which $WANTED_USER is currently logged in.

So, a way to solve your task is to walk over all usernames, registered in system and check what users occupy multiple terminals. Here a small script, written from scratch:

#!/usr/bin/perl

use strict;

open my $passwd_fd, '<', '/etc/passwd';
my @usernames = grep { s/:.*\s*$//; } <$passwd_fd>;

my $cmd;
my $ttys;
my $cnt;
foreach my $user(@usernames) {
	$cnt = 0;
	$cmd = "who | grep '$user' | awk '{ print \$2; }'";
	$ttys = qx/$cmd/;
	if($ttys) {
		$cnt = qx/echo -n '$ttys' | wc -l/;
	}
	if($cnt > 1) {
		print "User '$user' is logged on multiple terminals:\n".$ttys;
	}
}