README

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IMPORTANT

This library is somewhat not maintained anymore. But I'm glad that it did what I wanted the most. It moved people away from "ncurses" mindset and these days we see both re-implementations of termbox API in various languages and even possibly better libs with similar API design. If you're looking for a Go lib that provides terminal-based user interface facilities, I've heard that gdamore/tcell is good (never used it myself). Also for more complicated interfaces and/or computer games I recommend you to consider using HTML-based UI. Having said that, termbox still somewhat works. In fact I'm writing this line of text right now in godit (which is a text editor written using termbox-go). So, be aware. Good luck and have a nice day.

Termbox

Termbox is a library that provides a minimalistic API which allows the programmer to write text-based user interfaces. The library is crossplatform and has both terminal-based implementations on *nix operating systems and a winapi console based implementation for windows operating systems. The basic idea is an abstraction of the greatest common subset of features available on all major terminals and other terminal-like APIs in a minimalistic fashion. Small API means it is easy to implement, test, maintain and learn it, that's what makes the termbox a distinct library in its area.

Installation

Install and update this go package with go get -u github.com/nsf/termbox-go

Examples

For examples of what can be done take a look at various examples in the _demos directory. You can try them with go run: go run _demos/keyboard.go

There are also some interesting projects using termbox-go:

  • godit is an emacsish lightweight text editor written using termbox.
  • gotetris is an implementation of Tetris.
  • sokoban-go is an implementation of sokoban game.
  • hecate is a hex editor designed by Satan.
  • httopd is top for httpd logs.
  • mop is stock market tracker for hackers.
  • termui is a terminal dashboard.
  • termloop is a terminal game engine.
  • xterm-color-chart is a XTerm 256 color chart.
  • gocui is a minimalist Go library aimed at creating console user interfaces.
  • dry is an interactive cli to manage Docker containers.
  • pxl displays images in the terminal.
  • snake-game is an implementation of the Snake game.
  • gone is a CLI pomodoro® timer.
  • Spoof.go controllable movement spoofing from the cli.
  • rat lets you compose shell commands to build terminal applications.
  • httplab An interactive web server.
  • wot Wait time during command is completed.
  • 2048-go is 2048 in Go.
  • jv helps you view JSON on the command-line.
  • pinger helps you to monitor numerous hosts using ICMP ECHO_REQUEST.
  • vixl44 lets you create pixel art inside your terminal using vim movements.
  • zterm is a typing game inspired by http://zty.pe/.
  • gotypist is a fun touch-typing tutor following Steve Yegge's method.
  • cointop is an interactive terminal based UI application for tracking cryptocurrencies.
  • pexpo is a terminal sending ping tool written in Go.
  • jid is an interactive JSON drill down tool using filtering queries like jq.
  • nonograminGo is a nonogram (aka. picross) in Go.
  • tower-of-go is a tiny maze game that runs on the terminal.
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Documentation

Overview

    termbox is a library for creating cross-platform text-based interfaces

    Index

    Constants

    This section is empty.

    Variables

    View Source
    var (
    	IsInit bool = false
    )

      To know if termbox has been initialized or not

      Functions

      func AttributeToRGB

      func AttributeToRGB(attr Attribute) (uint8, uint8, uint8)

        AttributeToRGB converts an Attribute to the underlying rgb triplet. This is only useful if termbox is in Full RGB mode and the specified attribute is also an attribute with r, g, b specified

        func Clear

        func Clear(fg, bg Attribute) error

          Clears the internal back buffer.

          func Close

          func Close()

            Finalizes termbox library, should be called after successful initialization when termbox's functionality isn't required anymore.

            func Flush

            func Flush() error

              Synchronizes the internal back buffer with the terminal.

              func HideCursor

              func HideCursor()

                The shortcut for SetCursor(-1, -1).

                func Init

                func Init() error

                  Initializes termbox library. This function should be called before any other functions. After successful initialization, the library must be finalized using 'Close' function.

                  Example usage:

                  err := termbox.Init()
                  if err != nil {
                          panic(err)
                  }
                  defer termbox.Close()
                  

                  func Interrupt

                  func Interrupt()

                    Interrupt an in-progress call to PollEvent by causing it to return EventInterrupt. Note that this function will block until the PollEvent function has successfully been interrupted.

                    func SetBg

                    func SetBg(x, y int, bg Attribute)

                      Changes cell's background attributes in the internal back buffer at the specified position.

                      func SetCell

                      func SetCell(x, y int, ch rune, fg, bg Attribute)

                        Changes cell's parameters in the internal back buffer at the specified position.

                        func SetChar

                        func SetChar(x, y int, ch rune)

                          Changes cell's character (rune) in the internal back buffer at the specified position.

                          func SetCursor

                          func SetCursor(x, y int)

                            Sets the position of the cursor. See also HideCursor().

                            func SetFg

                            func SetFg(x, y int, fg Attribute)

                              Changes cell's foreground attributes in the internal back buffer at the specified position.

                              func Size

                              func Size() (width int, height int)

                                Returns the size of the internal back buffer (which is mostly the same as terminal's window size in characters). But it doesn't always match the size of the terminal window, after the terminal size has changed, the internal back buffer will get in sync only after Clear or Flush function calls.

                                func Sync

                                func Sync() error

                                  Sync comes handy when something causes desync between termbox's understanding of a terminal buffer and the reality. Such as a third party process. Sync forces a complete resync between the termbox and a terminal, it may not be visually pretty though.

                                  Types

                                  type Attribute

                                  type Attribute uint64
                                  const (
                                  	ColorDefault Attribute = iota
                                  	ColorBlack
                                  	ColorRed
                                  	ColorGreen
                                  	ColorYellow
                                  	ColorBlue
                                  	ColorMagenta
                                  	ColorCyan
                                  	ColorWhite
                                  	ColorDarkGray
                                  	ColorLightRed
                                  	ColorLightGreen
                                  	ColorLightYellow
                                  	ColorLightBlue
                                  	ColorLightMagenta
                                  	ColorLightCyan
                                  	ColorLightGray
                                  )

                                    Cell colors, you can combine a color with multiple attributes using bitwise OR ('|').

                                    const (
                                    	AttrBold Attribute = 1 << (iota + 9)
                                    	AttrBlink
                                    	AttrHidden
                                    	AttrDim
                                    	AttrUnderline
                                    	AttrCursive
                                    	AttrReverse
                                    )

                                      Cell attributes, it is possible to use multiple attributes by combining them using bitwise OR ('|'). Although, colors cannot be combined. But you can combine attributes and a single color.

                                      It's worth mentioning that some platforms don't support certain attributes. For example windows console doesn't support AttrUnderline. And on some terminals applying AttrBold to background may result in blinking text. Use them with caution and test your code on various terminals.

                                      func RGBToAttribute

                                      func RGBToAttribute(r uint8, g uint8, b uint8) Attribute

                                        RGBToAttribute is used to convert an rgb triplet into a termbox attribute. This attribute can only be applied when termbox is in Full RGB mode, otherwise it'll be ignored and no color will be drawn. R, G, B have to be in the range of 0 and 255.

                                        type Cell

                                        type Cell struct {
                                        	Ch rune
                                        	Fg Attribute
                                        	Bg Attribute
                                        }

                                          A cell, single conceptual entity on the screen. The screen is basically a 2d array of cells. 'Ch' is a unicode character, 'Fg' and 'Bg' are foreground and background attributes respectively.

                                          func CellBuffer

                                          func CellBuffer() []Cell

                                            Returns a slice into the termbox's back buffer. You can get its dimensions using 'Size' function. The slice remains valid as long as no 'Clear' or 'Flush' function calls were made after call to this function.

                                            func GetCell

                                            func GetCell(x, y int) Cell

                                              Returns the specified cell from the internal back buffer.

                                              type Event

                                              type Event struct {
                                              	Type   EventType // one of Event* constants
                                              	Mod    Modifier  // one of Mod* constants or 0
                                              	Key    Key       // one of Key* constants, invalid if 'Ch' is not 0
                                              	Ch     rune      // a unicode character
                                              	Width  int       // width of the screen
                                              	Height int       // height of the screen
                                              	Err    error     // error in case if input failed
                                              	MouseX int       // x coord of mouse
                                              	MouseY int       // y coord of mouse
                                              	N      int       // number of bytes written when getting a raw event
                                              }

                                                This type represents a termbox event. The 'Mod', 'Key' and 'Ch' fields are valid if 'Type' is EventKey. The 'Width' and 'Height' fields are valid if 'Type' is EventResize. The 'Err' field is valid if 'Type' is EventError.

                                                func ParseEvent

                                                func ParseEvent(data []byte) Event

                                                  After getting a raw event from PollRawEvent function call, you can parse it again into an ordinary one using termbox logic. That is parse an event as termbox would do it. Returned event in addition to usual Event struct fields sets N field to the amount of bytes used within 'data' slice. If the length of 'data' slice is zero or event cannot be parsed for some other reason, the function will return a special event type: EventNone.

                                                  IMPORTANT: EventNone may contain a non-zero N, which means you should skip these bytes, because termbox cannot recognize them.

                                                  NOTE: This API is experimental and may change in future.

                                                  func PollEvent

                                                  func PollEvent() Event

                                                    Wait for an event and return it. This is a blocking function call.

                                                    func PollRawEvent

                                                    func PollRawEvent(data []byte) Event

                                                      Wait for an event and return it. This is a blocking function call. Instead of EventKey and EventMouse it returns EventRaw events. Raw event is written into `data` slice and Event's N field is set to the amount of bytes written. The minimum required length of the 'data' slice is 1. This requirement may vary on different platforms.

                                                      NOTE: This API is experimental and may change in future.

                                                      type EventType

                                                      type EventType uint8
                                                      const (
                                                      	EventKey EventType = iota
                                                      	EventResize
                                                      	EventMouse
                                                      	EventError
                                                      	EventInterrupt
                                                      	EventRaw
                                                      	EventNone
                                                      )

                                                        Event type. See Event.Type field.

                                                        type InputMode

                                                        type InputMode int
                                                        const (
                                                        	InputEsc InputMode = 1 << iota
                                                        	InputAlt
                                                        	InputMouse
                                                        	InputCurrent InputMode = 0
                                                        )

                                                          Input mode. See SetInputMode function.

                                                          func SetInputMode

                                                          func SetInputMode(mode InputMode) InputMode

                                                            Sets termbox input mode. Termbox has two input modes:

                                                            1. Esc input mode. When ESC sequence is in the buffer and it doesn't match any known sequence. ESC means KeyEsc. This is the default input mode.

                                                            2. Alt input mode. When ESC sequence is in the buffer and it doesn't match any known sequence. ESC enables ModAlt modifier for the next keyboard event.

                                                            Both input modes can be OR'ed with Mouse mode. Setting Mouse mode bit up will enable mouse button press/release and drag events.

                                                            If 'mode' is InputCurrent, returns the current input mode. See also Input* constants.

                                                            type Key

                                                            type Key uint16
                                                            const (
                                                            	KeyF1 Key = 0xFFFF - iota
                                                            	KeyF2
                                                            	KeyF3
                                                            	KeyF4
                                                            	KeyF5
                                                            	KeyF6
                                                            	KeyF7
                                                            	KeyF8
                                                            	KeyF9
                                                            	KeyF10
                                                            	KeyF11
                                                            	KeyF12
                                                            	KeyInsert
                                                            	KeyDelete
                                                            	KeyHome
                                                            	KeyEnd
                                                            	KeyPgup
                                                            	KeyPgdn
                                                            	KeyArrowUp
                                                            	KeyArrowDown
                                                            	KeyArrowLeft
                                                            	KeyArrowRight
                                                            
                                                            	MouseLeft
                                                            	MouseMiddle
                                                            	MouseRight
                                                            	MouseRelease
                                                            	MouseWheelUp
                                                            	MouseWheelDown
                                                            )

                                                              Key constants, see Event.Key field.

                                                              const (
                                                              	KeyCtrlTilde      Key = 0x00
                                                              	KeyCtrl2          Key = 0x00
                                                              	KeyCtrlSpace      Key = 0x00
                                                              	KeyCtrlA          Key = 0x01
                                                              	KeyCtrlB          Key = 0x02
                                                              	KeyCtrlC          Key = 0x03
                                                              	KeyCtrlD          Key = 0x04
                                                              	KeyCtrlE          Key = 0x05
                                                              	KeyCtrlF          Key = 0x06
                                                              	KeyCtrlG          Key = 0x07
                                                              	KeyBackspace      Key = 0x08
                                                              	KeyCtrlH          Key = 0x08
                                                              	KeyTab            Key = 0x09
                                                              	KeyCtrlI          Key = 0x09
                                                              	KeyCtrlJ          Key = 0x0A
                                                              	KeyCtrlK          Key = 0x0B
                                                              	KeyCtrlL          Key = 0x0C
                                                              	KeyEnter          Key = 0x0D
                                                              	KeyCtrlM          Key = 0x0D
                                                              	KeyCtrlN          Key = 0x0E
                                                              	KeyCtrlO          Key = 0x0F
                                                              	KeyCtrlP          Key = 0x10
                                                              	KeyCtrlQ          Key = 0x11
                                                              	KeyCtrlR          Key = 0x12
                                                              	KeyCtrlS          Key = 0x13
                                                              	KeyCtrlT          Key = 0x14
                                                              	KeyCtrlU          Key = 0x15
                                                              	KeyCtrlV          Key = 0x16
                                                              	KeyCtrlW          Key = 0x17
                                                              	KeyCtrlX          Key = 0x18
                                                              	KeyCtrlY          Key = 0x19
                                                              	KeyCtrlZ          Key = 0x1A
                                                              	KeyEsc            Key = 0x1B
                                                              	KeyCtrlLsqBracket Key = 0x1B
                                                              	KeyCtrl3          Key = 0x1B
                                                              	KeyCtrl4          Key = 0x1C
                                                              	KeyCtrlBackslash  Key = 0x1C
                                                              	KeyCtrl5          Key = 0x1D
                                                              	KeyCtrlRsqBracket Key = 0x1D
                                                              	KeyCtrl6          Key = 0x1E
                                                              	KeyCtrl7          Key = 0x1F
                                                              	KeyCtrlSlash      Key = 0x1F
                                                              	KeyCtrlUnderscore Key = 0x1F
                                                              	KeySpace          Key = 0x20
                                                              	KeyBackspace2     Key = 0x7F
                                                              	KeyCtrl8          Key = 0x7F
                                                              )

                                                              type Modifier

                                                              type Modifier uint8
                                                              const (
                                                              	ModAlt Modifier = 1 << iota
                                                              	ModMotion
                                                              )

                                                                Alt modifier constant, see Event.Mod field and SetInputMode function.

                                                                type OutputMode

                                                                type OutputMode int
                                                                const (
                                                                	OutputCurrent OutputMode = iota
                                                                	OutputNormal
                                                                	Output256
                                                                	Output216
                                                                	OutputGrayscale
                                                                	OutputRGB
                                                                )

                                                                  Output mode. See SetOutputMode function.

                                                                  func SetOutputMode

                                                                  func SetOutputMode(mode OutputMode) OutputMode

                                                                    Sets the termbox output mode. Termbox has four output options:

                                                                    1. OutputNormal => [1..8]

                                                                    This mode provides 8 different colors:
                                                                        black, red, green, yellow, blue, magenta, cyan, white
                                                                    Shortcut: ColorBlack, ColorRed, ...
                                                                    Attributes: AttrBold, AttrUnderline, AttrReverse
                                                                    
                                                                    Example usage:
                                                                        SetCell(x, y, '@', ColorBlack | AttrBold, ColorRed);
                                                                    

                                                                    2. Output256 => [1..256]

                                                                    In this mode you can leverage the 256 terminal mode:
                                                                    0x01 - 0x08: the 8 colors as in OutputNormal
                                                                    0x09 - 0x10: Color* | AttrBold
                                                                    0x11 - 0xe8: 216 different colors
                                                                    0xe9 - 0x1ff: 24 different shades of grey
                                                                    
                                                                    Example usage:
                                                                        SetCell(x, y, '@', 184, 240);
                                                                        SetCell(x, y, '@', 0xb8, 0xf0);
                                                                    

                                                                    3. Output216 => [1..216]

                                                                    This mode supports the 3rd range of the 256 mode only.
                                                                    But you don't need to provide an offset.
                                                                    

                                                                    4. OutputGrayscale => [1..26]

                                                                    This mode supports the 4th range of the 256 mode
                                                                    and black and white colors from 3th range of the 256 mode
                                                                    But you don't need to provide an offset.
                                                                    

                                                                    In all modes, 0x00 represents the default color.

                                                                    `go run _demos/output.go` to see its impact on your terminal.

                                                                    If 'mode' is OutputCurrent, it returns the current output mode.

                                                                    Note that this may return a different OutputMode than the one requested, as the requested mode may not be available on the target platform.

                                                                    Directories

                                                                    Path Synopsis