# check if a password is valid

# this is just a subroutine, not a program

proc passwdchk {user password} {
   package require Expect

   log_user 0
   spawn -noecho su - $user /bin/yes
   set timeout -1
   expect "Password: "
   send "$password\r"
   expect "Sorry" {error}
}

# test it out
if {[catch {passwdchk [lindex $argv 0] [lindex $argv 1]}]} {
    puts "password is bad"
} else {
    puts "password is good"
}