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readline: migrate ansi/vt100 logic from tty to readline
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The overall goal here is to make readline more interoperable with other node
Streams like say a net.Socket instance, in "terminal" mode.

See #2922 for all the details.
Closes #2922.
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TooTallNate committed Mar 26, 2012
1 parent ab518ae commit aad12d0
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71 changes: 52 additions & 19 deletions doc/api/readline.markdown
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Expand Up @@ -3,43 +3,77 @@
Stability: 3 - Stable

To use this module, do `require('readline')`. Readline allows reading of a
stream (such as STDIN) on a line-by-line basis.
stream (such as `process.stdin`) on a line-by-line basis.

Note that once you've invoked this module, your node program will not
terminate until you've paused the interface. Here's how to allow your
program to gracefully pause:

var rl = require('readline');

var i = rl.createInterface(process.stdin, process.stdout, null);
i.question("What do you think of node.js?", function(answer) {
var i = rl.createInterface({
input: process.stdin,
output: process.stdout
});

i.question("What do you think of node.js? ", function(answer) {
// TODO: Log the answer in a database
console.log("Thank you for your valuable feedback.");
console.log("Thank you for your valuable feedback:", answer);

i.pause();
});

## rl.createInterface(input, output, completer)
## rl.createInterface(options)

Creates a readline `Interface` instance. Accepts an "options" Object that takes
the following values:

- `input` - the readable stream to listen to (Required).

- `output` - the writable stream to write readline data to (Required).

- `completer` - an optional function that is used for Tab autocompletion. See
below for an example of using this.

- `terminal` - pass `true` if the `input` and `output` streams should be treated
like a TTY, and have ANSI/VT100 escape codes written to it. Defaults to
checking `isTTY` on the `output` stream upon instantiation.

The `completer` function is given a the current line entered by the user, and
is supposed to return an Array with 2 entries:

Takes two streams and creates a readline interface. The `completer` function
is used for autocompletion. When given a substring, it returns `[[substr1,
substr2, ...], originalsubstring]`.
1. An Array with matching entries for the completion.

2. The substring that was used for the matching.

Which ends up looking something like:
`[[substr1, substr2, ...], originalsubstring]`.

Also `completer` can be run in async mode if it accepts two arguments:

function completer(linePartial, callback) {
callback(null, [['123'], linePartial]);
}
function completer(linePartial, callback) {
callback(null, [['123'], linePartial]);
}

`createInterface` is commonly used with `process.stdin` and
`process.stdout` in order to accept user input:

var readline = require('readline'),
rl = readline.createInterface(process.stdin, process.stdout);
var readline = require('readline');
var rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});

Once you have a readline instance, you most commonly listen for the `"line"` event.

If `terminal` is `true` for this instance then the `output` stream will get the
best compatability if it defines an `output.columns` property, and fires
a `"resize"` event on the `output` if/when the columns ever change
(`process.stdout` does this automatically when it is a TTY).

## Class: Interface

The class that represents a readline interface with a stdin and stdout
The class that represents a readline interface with an input and output
stream.

### rl.setPrompt(prompt, length)
Expand Down Expand Up @@ -72,18 +106,17 @@ Example usage:

### rl.pause()

Pauses the readline `in` stream, allowing it to be resumed later if needed.
Pauses the readline `input` stream, allowing it to be resumed later if needed.

### rl.resume()

Resumes the readline `in` stream.
Resumes the readline `input` stream.

### rl.write()

Writes to tty.
Writes to `output` stream.

This will also resume the `in` stream used with `createInterface` if it has
been paused.
This will also resume the `input` stream if it has been paused.

### Event: 'line'

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69 changes: 52 additions & 17 deletions doc/api/repl.markdown
Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
# REPL

A Read-Eval-Print-Loop (REPL) is available both as a standalone program and easily
includable in other programs. REPL provides a way to interactively run
JavaScript and see the results. It can be used for debugging, testing, or
A Read-Eval-Print-Loop (REPL) is available both as a standalone program and
easily includable in other programs. The REPL provides a way to interactively
run JavaScript and see the results. It can be used for debugging, testing, or
just trying things out.

By executing `node` without any arguments from the command-line you will be
Expand All @@ -19,26 +19,39 @@ dropped into the REPL. It has simplistic emacs line-editing.
2
3

For advanced line-editors, start node with the environmental variable `NODE_NO_READLINE=1`.
This will start the REPL in canonical terminal settings which will allow you to use with `rlwrap`.
For advanced line-editors, start node with the environmental variable
`NODE_NO_READLINE=1`. This will start the main and debugger REPL in canonical
terminal settings which will allow you to use with `rlwrap`.

For example, you could add this to your bashrc file:

alias node="env NODE_NO_READLINE=1 rlwrap node"


## repl.start([prompt], [stream], [eval], [useGlobal], [ignoreUndefined])
## repl.start(options)

Returns and starts a REPL with `prompt` as the prompt and `stream` for all I/O.
`prompt` is optional and defaults to `> `. `stream` is optional and defaults to
`process.stdin`. `eval` is optional too and defaults to async wrapper for
`eval()`.
Returns and starts a `REPLServer` instance. Accepts an "options" Object that
takes the following values:

If `useGlobal` is set to true, then the repl will use the global object,
instead of running scripts in a separate context. Defaults to `false`.
- `prompt` - the prompt and `stream` for all I/O. Defaults to `> `.

If `ignoreUndefined` is set to true, then the repl will not output return value
of command if it's `undefined`. Defaults to `false`.
- `input` - the readable stream to listen to. Defaults to `process.stdin`.

- `output` - the writable stream to write readline data to. Defaults to
`process.stdout`.

- `terminal` - pass `true` if the `stream` should be treated like a TTY, and
have ANSI/VT100 escape codes written to it. Defaults to checking `isTTY`
on the `output` stream upon instantiation.

- `eval` - function that will be used to eval each given line. Defaults to
an async wrapper for `eval()`. See below for an example of a custom `eval`.

- `useGlobal` - if set to `true`, then the repl will use the `global` object,
instead of running scripts in a separate context. Defaults to `false`.

- `ignoreUndefined` - if set to `true`, then the repl will not output the
return value of command if it's `undefined`. Defaults to `false`.

You can use your own `eval` function if it has following signature:

Expand All @@ -56,16 +69,32 @@ Here is an example that starts a REPL on stdin, a Unix socket, and a TCP socket:

connections = 0;

repl.start("node via stdin> ");
repl.start({
prompt: "node via stdin> ",
input: process.stdin,
output: process.stdout
});

net.createServer(function (socket) {
connections += 1;
repl.start("node via Unix socket> ", socket);
repl.start({
prompt: "node via Unix socket> ",
input: socket,
output: socket
}).on('exit', function() {
socket.end();
})
}).listen("/tmp/node-repl-sock");

net.createServer(function (socket) {
connections += 1;
repl.start("node via TCP socket> ", socket);
repl.start({
prompt: "node via TCP socket> ",
input: socket,
output: socket
}).on('exit', function() {
socket.end();
});
}).listen(5001);

Running this program from the command line will start a REPL on stdin. Other
Expand All @@ -76,6 +105,12 @@ TCP sockets.
By starting a REPL from a Unix socket-based server instead of stdin, you can
connect to a long-running node process without restarting it.

For an example of running a "full-featured" (`terminal`) REPL over
a `net.Server` and `net.Socket` instance, see: https://gist.github.com/2209310

For an example of running a REPL instance over `curl(1)`,
see: https://gist.github.com/2053342

### Event: 'exit'

`function () {}`
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74 changes: 59 additions & 15 deletions doc/api/tty.markdown
Original file line number Diff line number Diff line change
Expand Up @@ -2,20 +2,18 @@

Stability: 3 - Stable

Use `require('tty')` to access this module.

Example:

var tty = require('tty');
process.stdin.resume();
tty.setRawMode(true);
process.stdin.on('keypress', function(char, key) {
if (key && key.ctrl && key.name == 'c') {
console.log('graceful exit');
process.exit()
}
});
The `tty` module houses the `tty.ReadStream` and `tty.WriteStream` classes. In
most cases, you will not need to use this module directly.

When node detects that it is being run inside a TTY context, then `process.stdin`
will be a `tty.ReadStream` instance and `process.stdout` will be
a `tty.WriteStream` instance. The preferred way to check if node is being run in
a TTY context is to check `process.stdout.isTTY`:

$ node -p -e "Boolean(process.stdout.isTTY)"
true
$ node -p -e "Boolean(process.stdout.isTTY)" | cat
false


## tty.isatty(fd)
Expand All @@ -26,5 +24,51 @@ terminal.

## tty.setRawMode(mode)

`mode` should be `true` or `false`. This sets the properties of the current
process's stdin fd to act either as a raw device or default.
Deprecated. Use `tty.ReadStream#setRawMode()` instead.


## Class: ReadStream

A `net.Socket` subclass that represents the readable portion of a tty. In normal
circumstances, `process.stdin` will be the only `tty.ReadStream` instance in any
node program (only when `isatty(0)` is true).

### rs.isRaw

A `Boolean` that is initialized to `false`. It represents the current "raw" state
of the `tty.ReadStream` instance.

### rs.setRawMode(mode)

`mode` should be `true` or `false`. This sets the properties of the
`tty.ReadStream` to act either as a raw device or default. `isRaw` will be set
to the resulting mode.


## Class WriteStream

A `net.Socket` subclass that represents the writable portion of a tty. In normal
circumstances, `process.stdout` will be the only `tty.WriteStream` instance
ever created (and only when `isatty(1)` is true).

### ws.columns

A `Number` that gives the number of columns the TTY currently has. This property
gets updated on "resize" events.

### ws.rows

A `Number` that gives the number of rows the TTY currently has. This property
gets updated on "resize" events.

### Event: 'resize'

`function () {}`

Emitted by `refreshSize()` when either of the `columns` or `rows` properties
has changed.

process.stdout.on('resize', function() {
console.log('screen size has changed!');
console.log(process.stdout.columns + 'x' + process.stdout.rows);
});
16 changes: 9 additions & 7 deletions lib/_debugger.js
Original file line number Diff line number Diff line change
Expand Up @@ -745,15 +745,17 @@ function Interface(stdin, stdout, args) {
this.stdout = stdout;
this.args = args;

var streams = {
stdin: stdin,
stdout: stdout
};

// Two eval modes are available: controlEval and debugEval
// But controlEval is used by default
this.repl = new repl.REPLServer('debug> ', streams,
this.controlEval.bind(this), false, true);
this.repl = repl.start({
prompt: 'debug> ',
input: this.stdin,
output: this.stdout,
terminal: !parseInt(process.env['NODE_NO_READLINE'], 10),
eval: this.controlEval.bind(this),
useGlobal: false,
ignoreUndefined: true
});

// Do not print useless warning
repl._builtinLibs.splice(repl._builtinLibs.indexOf('repl'), 1);
Expand Down
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