Lispect
=======

- A text-terminal automation tool similar to [expect(1)] of UNIX and Linux
- It runs on Windows 10 and later, and Linux
- The script is written in the subset of [ISLisp] ([gmnlisp])

[expect(1)]: https://linux.die.net/man/1/expect

**example.lsp**

```example.lsp
(block main
  (if (< (length args) 2)
    (progn
      (format (error-output) "Usage: ~A ~A HOSTNAME PASSWORD~%" $EXECUTABLE_NAME $PROGRAM_NAME)
      (return-from main nil)
      )
    )
  (defglobal host (car args))
  (defglobal password (cadr args))

  (spawn "ssh" host)
  (expect*
    ("[fingerprint])?"
     (sendln "yes")
     (expect "password: ")
     (sendln password)
     )
    ("password: "
     (sendln password)
     )
    ("Connection refused"
     (return-from main nil)
     )
    (30
     (format (error-output) "TIME OUT~%")
     (return-from main nil)
     )
    )
  (expect "$ ")
  (sendln "echo YOU CAN CALL SOME COMMAND HERE")
  (expect "$ ")
  (sendln "exit")
  )
```

### Functions and variables

Parameters enclosed in curly braces {...} are optional and can be omitted.

- `(send {'interval MS} "STRING")`
    - Send STRING to the terminal
    - Specify the `'interval MS` option to make the program wait MS milliseconds before outputting each character
- `(sendln {'interval MS} "STRING")`
    - send STRING and Enter-key to the terminal
- `(expect {'timeout SEC} "STRING-0" "STRING-1" ...)`
    - Wait until STRINGs are found on the terminal
    - When STRING-n is found on the terminal, it will return n
    - If a timeout occurs after SEC seconds have elapsed, it returns -1
- `(expect* ("STRING-0" COMMANDS-0...) ("STRING-1"...)... (SEC COMMANDS-FOR-TIMEOUT...))`
    - When STRING-n is found on the terminal, COMMANDS-n will be executed
    - After SEC seconds have elapsed, COMMANDS-FOR-TIMEOUT will be executed
- `(spawn "COMMANDNAME" "ARG-1" ...)`
    - Start the executable file
- `args`
    - The list of command line arguments
- `$PROGRAM_NAME`
    - The path of the script
- `$EXECUTABLE_NAME`
    - The path of the executable of lispect

Other functions are defined on [ISLisp]

### Comparison with [Expect-lua] and [expect(1)]

|                       | [Expect-lua]          | Lispect       |[expect(1)]
|-----------------------|-----------------------|---------------|-----------
| Started               | 2017                  | 2024          | 1990?
| Script                | Lua ([GophaLua])      | ISLisp ([gmnlisp]) | tcl
| Windows 7/8           | Supported             | Not Supported | Not Supported
| Windows 10/11         | Supported             | Supported     | Not Supported
| Linux                 | Not Supported         | Supported     | Supported
| Mechanisms            | [ReadConsoleOutputW]  |[PseudoConsole]| PseudoConsole
| Read Misses           | Possible[^1]          | Unlikely      | Never
| Stdout Redirection    | Unavailable           | Available     | Available
| Status                | Stable                |Work in Progress| Stable

[^1]: When the output is too excessive, there might be some dropped data

[ReadConsoleOutputW]: https://github.com/hymkor/expect/issues/34
[PseudoConsole]: https://learn.microsoft.com/en-us/windows/console/creating-a-pseudoconsole-session
[Expect-lua]: https://github.com/hymkor/expect

### Technologies used

- [Creating a Pseudoconsole session - Windows Console | Microsoft Learn](https://learn.microsoft.com/en-us/windows/console/creating-a-pseudoconsole-session)
- [aymanbagabas/go-pty: Cross platform Go Pty interface](https://github.com/aymanbagabas/go-pty)
- [hymkor/gmnlisp: gmnlisp - the subset of ISLisp][gmnlisp]

[ISLisp]: http://islisp.org
[gmnlisp]: https://github.com/hymkor/gmnlisp
[GophaLua]: https://github.com/yuin/gopher-lua