{ "type": "module", "source": "doc/api/tty.md", "modules": [ { "textRaw": "TTY", "name": "tty", "introduced_in": "v0.10.0", "stability": 2, "stabilityText": "Stable", "desc": "
The tty
module provides the tty.ReadStream
and tty.WriteStream
classes.\nIn most cases, it will not be necessary or possible to use this module directly.\nHowever, it can be accessed using:
const tty = require('tty');\n
\nWhen Node.js detects that it is being run with a text terminal (\"TTY\")\nattached, process.stdin
will, by default, be initialized as an instance of\ntty.ReadStream
and both process.stdout
and process.stderr
will, by\ndefault be instances of tty.WriteStream
. The preferred method of determining\nwhether Node.js is being run within a TTY context is to check that the value of\nthe process.stdout.isTTY
property is true
:
$ node -p -e \"Boolean(process.stdout.isTTY)\"\ntrue\n$ node -p -e \"Boolean(process.stdout.isTTY)\" | cat\nfalse\n
\nIn most cases, there should be little to no reason for an application to\nmanually create instances of the tty.ReadStream
and tty.WriteStream
\nclasses.
The tty.ReadStream
class is a subclass of net.Socket
that represents the\nreadable side of a TTY. In normal circumstances process.stdin
will be the\nonly tty.ReadStream
instance in a Node.js process and there should be no\nreason to create additional instances.
A boolean
that is true
if the TTY is currently configured to operate as a\nraw device. Defaults to false
.
A boolean
that is always true
for tty.ReadStream
instances.
Allows configuration of tty.ReadStream
so that it operates as a raw device.
When in raw mode, input is always available character-by-character, not\nincluding modifiers. Additionally, all special processing of characters by the\nterminal is disabled, including echoing input characters.\nNote that CTRL
+C
will no longer cause a SIGINT
when in this mode.
The tty.WriteStream
class is a subclass of net.Socket
that represents\nthe writable side of a TTY. In normal circumstances, process.stdout
and\nprocess.stderr
will be the only tty.WriteStream
instances created for a\nNode.js process and there should be no reason to create additional instances.
The 'resize'
event is emitted whenever either of the writeStream.columns
\nor writeStream.rows
properties have changed. No arguments are passed to the\nlistener callback when called.
process.stdout.on('resize', () => {\n console.log('screen size has changed!');\n console.log(`${process.stdout.columns}x${process.stdout.rows}`);\n});\n
"
}
],
"methods": [
{
"textRaw": "writeStream.clearLine(dir)",
"type": "method",
"name": "clearLine",
"meta": {
"added": [
"v0.7.7"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`dir` {number}",
"name": "dir",
"type": "number",
"options": [
{
"textRaw": "`-1` - to the left from cursor",
"name": "-1",
"desc": "to the left from cursor"
},
{
"textRaw": "`1` - to the right from cursor",
"name": "1",
"desc": "to the right from cursor"
},
{
"textRaw": "`0` - the entire line",
"name": "0",
"desc": "the entire line"
}
]
}
]
}
],
"desc": "writeStream.clearLine()
clears the current line of this WriteStream
in a\ndirection identified by dir
.
writeStream.clearScreenDown()
clears this WriteStream
from the current\ncursor down.
writeStream.cursorTo()
moves this WriteStream
's cursor to the specified\nposition.
Returns:
\n1
for 2,4
for 16,8
for 256,24
for 16,777,216\ncolors supported.Use this to determine what colors the terminal supports. Due to the nature of\ncolors in terminals it is possible to either have false positives or false\nnegatives. It depends on process information and the environment variables that\nmay lie about what terminal is used.\nTo enforce a specific behavior without relying on process.env
it is possible\nto pass in an object with different settings.
Use the NODE_DISABLE_COLORS
environment variable to enforce this function to\nalways return 1.
writeStream.getWindowSize()
returns the size of the TTY\ncorresponding to this WriteStream
. The array is of the type\n[numColumns, numRows]
where numColumns
and numRows
represent the number\nof columns and rows in the corresponding TTY.
Returns true
if the writeStream
supports at least as many colors as provided\nin count
. Minimum support is 2 (black and white).
This has the same false positives and negatives as described in\nwriteStream.getColorDepth()
.
process.stdout.hasColors();\n// Returns true or false depending on if `stdout` supports at least 16 colors.\nprocess.stdout.hasColors(256);\n// Returns true or false depending on if `stdout` supports at least 256 colors.\nprocess.stdout.hasColors({ TMUX: '1' });\n// Returns true.\nprocess.stdout.hasColors(2 ** 24, { TMUX: '1' });\n// Returns false (the environment setting pretends to support 2 ** 8 colors).\n
"
},
{
"textRaw": "writeStream.moveCursor(dx, dy)",
"type": "method",
"name": "moveCursor",
"meta": {
"added": [
"v0.7.7"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`dx` {number}",
"name": "dx",
"type": "number"
},
{
"textRaw": "`dy` {number}",
"name": "dy",
"type": "number"
}
]
}
],
"desc": "writeStream.moveCursor()
moves this WriteStream
's cursor relative to its\ncurrent position.
A number
specifying the number of columns the TTY currently has. This property\nis updated whenever the 'resize'
event is emitted.
A boolean
that is always true
.
A number
specifying the number of rows the TTY currently has. This property\nis updated whenever the 'resize'
event is emitted.
The tty.isatty()
method returns true
if the given fd
is associated with\na TTY and false
if it is not, including whenever fd
is not a non-negative\ninteger.