convert string into an integer

Does your data literally look like mserver_2 or mswerver_10? And you're trying to parse that string to get just the digits after the underscore? If so, you can use getfield to split the string and take just the second field:

set test_string mserver_9
set digit [getfield $test_string "_" 2]
log local0. $digit

This logs 9. If this isn't what you meant, can you clarify?

Thanks,

Aaron