upload.exp

#!/usr/bin/expect
set arg1 [lindex $argv 0]
set arg2 [lindex $argv 1]
set arg3 [lindex $argv 2]
set timeout 1000
spawn sftp "$arg2"
expect {
  yes {
    send "yes\r"
    exp_continue
  }
  ass {
    send "$arg3\r"
    exp_continue
  }
  sftp {
    send "put $arg1\r"
    expect {
      100% {
        send "quit\r"
        exp_continue
      }
    }
  }
}