pop3.exp - connects to pop3 server using telnet

pop3.exp

#!/usr/bin/expect

proc help {} {
  global argv0
  puts ""
  puts "pop3.exp - connects to pop3 server using telnet"
  puts ""
  puts "usage: $argv0 <host> <user>"
  puts "       it will prompt for password"
  puts ""
}

set maskpw 1    ;# set to 1 to mask password using asterisks
set interact 1  ;# set to 1 to enable user control after login
set timeout 60
log_user 0

set host [lindex $argv 0]
set user [lindex $argv 1]
set port "110"

if {[llength $argv] == 0} { help; exit 0 }
if { $host == "" || $user == "" } { help; exit 1 }

set buf ""; set output ""
if {[catch {eval spawn telnet $host $port} err]} {
  send_user "ERROR: $bin $host $port $err\n"
  continue
}
expect {
  "Trying *" { set buf "$expect_out(buffer)" }
  "Connection to *" { set buf "expect_out(buffer)" }
  "telnet: could not resolve *" { send_user "$expect_out(buffer)\n"; exit 1 }
  send_user "$buf\n"
}
expect { 
  -re "\\+OK (POP3|Server) ready" { send_user "$expect_out(buffer)\n"; send "USER $user\r" }
  "*Connection closed*" { send_user "$expect_out(buffer)\n"; exit 1 }
}
expect "+OK" {
  send_user "$expect_out(buffer)\n" 
  send_user "\nEnter password: "
  if { $maskpw == 1 } { stty -echo }
  expect_user -re "(.*)\n"
  stty echo
  send "PASS $expect_out(1,string)\r"
}
expect {
  "PASS *" {
    set buf "$expect_out(buffer)"
    if { $maskpw == 1 } {
      set regex {^[\r\n]{2}?PASS (\S*)[\r\n]{2}?.*}
      set passlen "[string length [regsub $regex $buf "\\1"]]"
      set output "[regsub $regex $buf [string repeat * $passlen]]"
      send_user "$output"
    } else {
      send_user "$buf"
    }
  }
  "*Connection closed*" { send_user "$expect_out(buffer)\n"; exit 1 }
}
expect {
  -re "\\+OK (server ready|Logged in)" {
    send_user "\n$expect_out(buffer)\n"
    if { $interact == 0 } {
      send "QUIT\r"
    } else {
      send_user "\nENABLING INTERACT...\n"
      send_user "POP COMMANDS: STAT, LIST, RETR n, DELE n, RSET, TOP msg n, QUIT\n"
      log_user 1
      interact
      exit 0
    }
  }
  -ex "-ERR LOGIN failed" { send_user -- "$expect_out(buffer)\n"; exit 1 }
  "*Connection closed*" { send_user "$expect_out(buffer)\n"; exit 1 }
}
expect {
  "+OK *" {
    send_user "$expect_out(buffer)\n"
    send_user "LOGIN SUCCESS: $host $user\n"
    exit 0
  }
}