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Package color

import "github.com/fatih/color"
Overview
Index

Overview ▾

Package color is an ANSI color package to output colorized or SGR defined output to the standard output. The API can be used in several way, pick one that suits you.

Use simple and default helper functions with predefined foreground colors:

color.Cyan("Prints text in cyan.")

// a newline will be appended automatically
color.Blue("Prints %s in blue.", "text")

// More default foreground colors..
color.Red("We have red")
color.Yellow("Yellow color too!")
color.Magenta("And many others ..")

// Hi-intensity colors
color.HiGreen("Bright green color.")
color.HiBlack("Bright black means gray..")
color.HiWhite("Shiny white color!")

However there are times where custom color mixes are required. Below are some examples to create custom color objects and use the print functions of each separate color object.

// Create a new color object
c := color.New(color.FgCyan).Add(color.Underline)
c.Println("Prints cyan text with an underline.")

// Or just add them to New()
d := color.New(color.FgCyan, color.Bold)
d.Printf("This prints bold cyan %s\n", "too!.")

// Mix up foreground and background colors, create new mixes!
red := color.New(color.FgRed)

boldRed := red.Add(color.Bold)
boldRed.Println("This will print text in bold red.")

whiteBackground := red.Add(color.BgWhite)
whiteBackground.Println("Red text with White background.")

// Use your own io.Writer output
color.New(color.FgBlue).Fprintln(myWriter, "blue color!")

blue := color.New(color.FgBlue)
blue.Fprint(myWriter, "This will print text in blue.")

You can create PrintXxx functions to simplify even more:

// Create a custom print function for convenient
red := color.New(color.FgRed).PrintfFunc()
red("warning")
red("error: %s", err)

// Mix up multiple attributes
notice := color.New(color.Bold, color.FgGreen).PrintlnFunc()
notice("don't forget this...")

You can also FprintXxx functions to pass your own io.Writer:

blue := color.New(FgBlue).FprintfFunc()
blue(myWriter, "important notice: %s", stars)

// Mix up with multiple attributes
success := color.New(color.Bold, color.FgGreen).FprintlnFunc()
success(myWriter, don't forget this...")

Or create SprintXxx functions to mix strings with other non-colorized strings:

yellow := New(FgYellow).SprintFunc()
red := New(FgRed).SprintFunc()

fmt.Printf("this is a %s and this is %s.\n", yellow("warning"), red("error"))

info := New(FgWhite, BgGreen).SprintFunc()
fmt.Printf("this %s rocks!\n", info("package"))

Windows support is enabled by default. All Print functions work as intended. However only for color.SprintXXX functions, user should use fmt.FprintXXX and set the output to color.Output:

fmt.Fprintf(color.Output, "Windows support: %s", color.GreenString("PASS"))

info := New(FgWhite, BgGreen).SprintFunc()
fmt.Fprintf(color.Output, "this %s rocks!\n", info("package"))

Using with existing code is possible. Just use the Set() method to set the standard output to the given parameters. That way a rewrite of an existing code is not required.

// Use handy standard colors.
color.Set(color.FgYellow)

fmt.Println("Existing text will be now in Yellow")
fmt.Printf("This one %s\n", "too")

color.Unset() // don't forget to unset

// You can mix up parameters
color.Set(color.FgMagenta, color.Bold)
defer color.Unset() // use it in your function

fmt.Println("All text will be now bold magenta.")

There might be a case where you want to disable color output (for example to pipe the standard output of your app to somewhere else). `Color` has support to disable colors both globally and for single color definition. For example suppose you have a CLI app and a `--no-color` bool flag. You can easily disable the color output with:

var flagNoColor = flag.Bool("no-color", false, "Disable color output")

if *flagNoColor {
	color.NoColor = true // disables colorized output
}

It also has support for single color definitions (local). You can disable/enable color output on the fly:

c := color.New(color.FgCyan)
c.Println("Prints cyan text")

c.DisableColor()
c.Println("This is printed without any color")

c.EnableColor()
c.Println("This prints again cyan...")

Index ▾

Variables
func Black(format string, a ...interface{})
func BlackString(format string, a ...interface{}) string
func Blue(format string, a ...interface{})
func BlueString(format string, a ...interface{}) string
func Cyan(format string, a ...interface{})
func CyanString(format string, a ...interface{}) string
func Green(format string, a ...interface{})
func GreenString(format string, a ...interface{}) string
func HiBlack(format string, a ...interface{})
func HiBlackString(format string, a ...interface{}) string
func HiBlue(format string, a ...interface{})
func HiBlueString(format string, a ...interface{}) string
func HiCyan(format string, a ...interface{})
func HiCyanString(format string, a ...interface{}) string
func HiGreen(format string, a ...interface{})
func HiGreenString(format string, a ...interface{}) string
func HiMagenta(format string, a ...interface{})
func HiMagentaString(format string, a ...interface{}) string
func HiRed(format string, a ...interface{})
func HiRedString(format string, a ...interface{}) string
func HiWhite(format string, a ...interface{})
func HiWhiteString(format string, a ...interface{}) string
func HiYellow(format string, a ...interface{})
func HiYellowString(format string, a ...interface{}) string
func Magenta(format string, a ...interface{})
func MagentaString(format string, a ...interface{}) string
func Red(format string, a ...interface{})
func RedString(format string, a ...interface{}) string
func Unset()
func White(format string, a ...interface{})
func WhiteString(format string, a ...interface{}) string
func Yellow(format string, a ...interface{})
func YellowString(format string, a ...interface{}) string
type Attribute
type Color
    func New(value ...Attribute) *Color
    func Set(p ...Attribute) *Color
    func (c *Color) Add(value ...Attribute) *Color
    func (c *Color) DisableColor()
    func (c *Color) EnableColor()
    func (c *Color) Equals(c2 *Color) bool
    func (c *Color) Fprint(w io.Writer, a ...interface{}) (n int, err error)
    func (c *Color) FprintFunc() func(w io.Writer, a ...interface{})
    func (c *Color) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error)
    func (c *Color) FprintfFunc() func(w io.Writer, format string, a ...interface{})
    func (c *Color) Fprintln(w io.Writer, a ...interface{}) (n int, err error)
    func (c *Color) FprintlnFunc() func(w io.Writer, a ...interface{})
    func (c *Color) Print(a ...interface{}) (n int, err error)
    func (c *Color) PrintFunc() func(a ...interface{})
    func (c *Color) Printf(format string, a ...interface{}) (n int, err error)
    func (c *Color) PrintfFunc() func(format string, a ...interface{})
    func (c *Color) Println(a ...interface{}) (n int, err error)
    func (c *Color) PrintlnFunc() func(a ...interface{})
    func (c *Color) Set() *Color
    func (c *Color) Sprint(a ...interface{}) string
    func (c *Color) SprintFunc() func(a ...interface{}) string
    func (c *Color) Sprintf(format string, a ...interface{}) string
    func (c *Color) SprintfFunc() func(format string, a ...interface{}) string
    func (c *Color) Sprintln(a ...interface{}) string
    func (c *Color) SprintlnFunc() func(a ...interface{}) string

Package files

color.go doc.go

Variables

var (
    // NoColor defines if the output is colorized or not. It's dynamically set to
    // false or true based on the stdout's file descriptor referring to a terminal
    // or not. This is a global option and affects all colors. For more control
    // over each color block use the methods DisableColor() individually.
    NoColor = os.Getenv("TERM") == "dumb" ||
        (!isatty.IsTerminal(os.Stdout.Fd()) && !isatty.IsCygwinTerminal(os.Stdout.Fd()))

    // Output defines the standard output of the print functions. By default
    // os.Stdout is used.
    Output = colorable.NewColorableStdout()

    // Error defines a color supporting writer for os.Stderr.
    Error = colorable.NewColorableStderr()
)

func Black

func Black(format string, a ...interface{})

Black is a convenient helper function to print with black foreground. A newline is appended to format by default.

func BlackString

func BlackString(format string, a ...interface{}) string

BlackString is a convenient helper function to return a string with black foreground.

func Blue

func Blue(format string, a ...interface{})

Blue is a convenient helper function to print with blue foreground. A newline is appended to format by default.

func BlueString

func BlueString(format string, a ...interface{}) string

BlueString is a convenient helper function to return a string with blue foreground.

func Cyan

func Cyan(format string, a ...interface{})

Cyan is a convenient helper function to print with cyan foreground. A newline is appended to format by default.

func CyanString

func CyanString(format string, a ...interface{}) string

CyanString is a convenient helper function to return a string with cyan foreground.

func Green

func Green(format string, a ...interface{})

Green is a convenient helper function to print with green foreground. A newline is appended to format by default.

func GreenString

func GreenString(format string, a ...interface{}) string

GreenString is a convenient helper function to return a string with green foreground.

func HiBlack

func HiBlack(format string, a ...interface{})

HiBlack is a convenient helper function to print with hi-intensity black foreground. A newline is appended to format by default.

func HiBlackString

func HiBlackString(format string, a ...interface{}) string

HiBlackString is a convenient helper function to return a string with hi-intensity black foreground.

func HiBlue

func HiBlue(format string, a ...interface{})

HiBlue is a convenient helper function to print with hi-intensity blue foreground. A newline is appended to format by default.

func HiBlueString

func HiBlueString(format string, a ...interface{}) string

HiBlueString is a convenient helper function to return a string with hi-intensity blue foreground.

func HiCyan

func HiCyan(format string, a ...interface{})

HiCyan is a convenient helper function to print with hi-intensity cyan foreground. A newline is appended to format by default.

func HiCyanString

func HiCyanString(format string, a ...interface{}) string

HiCyanString is a convenient helper function to return a string with hi-intensity cyan foreground.

func HiGreen

func HiGreen(format string, a ...interface{})

HiGreen is a convenient helper function to print with hi-intensity green foreground. A newline is appended to format by default.

func HiGreenString

func HiGreenString(format string, a ...interface{}) string

HiGreenString is a convenient helper function to return a string with hi-intensity green foreground.

func HiMagenta

func HiMagenta(format string, a ...interface{})

HiMagenta is a convenient helper function to print with hi-intensity magenta foreground. A newline is appended to format by default.

func HiMagentaString

func HiMagentaString(format string, a ...interface{}) string

HiMagentaString is a convenient helper function to return a string with hi-intensity magenta foreground.

func HiRed

func HiRed(format string, a ...interface{})

HiRed is a convenient helper function to print with hi-intensity red foreground. A newline is appended to format by default.

func HiRedString

func HiRedString(format string, a ...interface{}) string

HiRedString is a convenient helper function to return a string with hi-intensity red foreground.

func HiWhite

func HiWhite(format string, a ...interface{})

HiWhite is a convenient helper function to print with hi-intensity white foreground. A newline is appended to format by default.

func HiWhiteString

func HiWhiteString(format string, a ...interface{}) string

HiWhiteString is a convenient helper function to return a string with hi-intensity white foreground.

func HiYellow

func HiYellow(format string, a ...interface{})

HiYellow is a convenient helper function to print with hi-intensity yellow foreground. A newline is appended to format by default.

func HiYellowString

func HiYellowString(format string, a ...interface{}) string

HiYellowString is a convenient helper function to return a string with hi-intensity yellow foreground.

func Magenta

func Magenta(format string, a ...interface{})

Magenta is a convenient helper function to print with magenta foreground. A newline is appended to format by default.

func MagentaString

func MagentaString(format string, a ...interface{}) string

MagentaString is a convenient helper function to return a string with magenta foreground.

func Red

func Red(format string, a ...interface{})

Red is a convenient helper function to print with red foreground. A newline is appended to format by default.

func RedString

func RedString(format string, a ...interface{}) string

RedString is a convenient helper function to return a string with red foreground.

func Unset

func Unset()

Unset resets all escape attributes and clears the output. Usually should be called after Set().

func White

func White(format string, a ...interface{})

White is a convenient helper function to print with white foreground. A newline is appended to format by default.

func WhiteString

func WhiteString(format string, a ...interface{}) string

WhiteString is a convenient helper function to return a string with white foreground.

func Yellow

func Yellow(format string, a ...interface{})

Yellow is a convenient helper function to print with yellow foreground. A newline is appended to format by default.

func YellowString

func YellowString(format string, a ...interface{}) string

YellowString is a convenient helper function to return a string with yellow foreground.

type Attribute

Attribute defines a single SGR Code

type Attribute int

Base attributes

const (
    Reset Attribute = iota
    Bold
    Faint
    Italic
    Underline
    BlinkSlow
    BlinkRapid
    ReverseVideo
    Concealed
    CrossedOut
)

Foreground text colors

const (
    FgBlack Attribute = iota + 30
    FgRed
    FgGreen
    FgYellow
    FgBlue
    FgMagenta
    FgCyan
    FgWhite
)

Foreground Hi-Intensity text colors

const (
    FgHiBlack Attribute = iota + 90
    FgHiRed
    FgHiGreen
    FgHiYellow
    FgHiBlue
    FgHiMagenta
    FgHiCyan
    FgHiWhite
)

Background text colors

const (
    BgBlack Attribute = iota + 40
    BgRed
    BgGreen
    BgYellow
    BgBlue
    BgMagenta
    BgCyan
    BgWhite
)

Background Hi-Intensity text colors

const (
    BgHiBlack Attribute = iota + 100
    BgHiRed
    BgHiGreen
    BgHiYellow
    BgHiBlue
    BgHiMagenta
    BgHiCyan
    BgHiWhite
)

type Color

Color defines a custom color object which is defined by SGR parameters.

type Color struct {
    // contains filtered or unexported fields
}

func New

func New(value ...Attribute) *Color

New returns a newly created color object.

func Set

func Set(p ...Attribute) *Color

Set sets the given parameters immediately. It will change the color of output with the given SGR parameters until color.Unset() is called.

func (*Color) Add

func (c *Color) Add(value ...Attribute) *Color

Add is used to chain SGR parameters. Use as many as parameters to combine and create custom color objects. Example: Add(color.FgRed, color.Underline).

func (*Color) DisableColor

func (c *Color) DisableColor()

DisableColor disables the color output. Useful to not change any existing code and still being able to output. Can be used for flags like "--no-color". To enable back use EnableColor() method.

func (*Color) EnableColor

func (c *Color) EnableColor()

EnableColor enables the color output. Use it in conjunction with DisableColor(). Otherwise this method has no side effects.

func (*Color) Equals

func (c *Color) Equals(c2 *Color) bool

Equals returns a boolean value indicating whether two colors are equal.

func (*Color) Fprint

func (c *Color) Fprint(w io.Writer, a ...interface{}) (n int, err error)

Fprint formats using the default formats for its operands and writes to w. Spaces are added between operands when neither is a string. It returns the number of bytes written and any write error encountered. On Windows, users should wrap w with colorable.NewColorable() if w is of type *os.File.

func (*Color) FprintFunc

func (c *Color) FprintFunc() func(w io.Writer, a ...interface{})

FprintFunc returns a new function that prints the passed arguments as colorized with color.Fprint().

func (*Color) Fprintf

func (c *Color) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error)

Fprintf formats according to a format specifier and writes to w. It returns the number of bytes written and any write error encountered. On Windows, users should wrap w with colorable.NewColorable() if w is of type *os.File.

func (*Color) FprintfFunc

func (c *Color) FprintfFunc() func(w io.Writer, format string, a ...interface{})

FprintfFunc returns a new function that prints the passed arguments as colorized with color.Fprintf().

func (*Color) Fprintln

func (c *Color) Fprintln(w io.Writer, a ...interface{}) (n int, err error)

Fprintln formats using the default formats for its operands and writes to w. Spaces are always added between operands and a newline is appended. On Windows, users should wrap w with colorable.NewColorable() if w is of type *os.File.

func (*Color) FprintlnFunc

func (c *Color) FprintlnFunc() func(w io.Writer, a ...interface{})

FprintlnFunc returns a new function that prints the passed arguments as colorized with color.Fprintln().

func (*Color) Print

func (c *Color) Print(a ...interface{}) (n int, err error)

Print formats using the default formats for its operands and writes to standard output. Spaces are added between operands when neither is a string. It returns the number of bytes written and any write error encountered. This is the standard fmt.Print() method wrapped with the given color.

func (*Color) PrintFunc

func (c *Color) PrintFunc() func(a ...interface{})

PrintFunc returns a new function that prints the passed arguments as colorized with color.Print().

func (*Color) Printf

func (c *Color) Printf(format string, a ...interface{}) (n int, err error)

Printf formats according to a format specifier and writes to standard output. It returns the number of bytes written and any write error encountered. This is the standard fmt.Printf() method wrapped with the given color.

func (*Color) PrintfFunc

func (c *Color) PrintfFunc() func(format string, a ...interface{})

PrintfFunc returns a new function that prints the passed arguments as colorized with color.Printf().

func (*Color) Println

func (c *Color) Println(a ...interface{}) (n int, err error)

Println formats using the default formats for its operands and writes to standard output. Spaces are always added between operands and a newline is appended. It returns the number of bytes written and any write error encountered. This is the standard fmt.Print() method wrapped with the given color.

func (*Color) PrintlnFunc

func (c *Color) PrintlnFunc() func(a ...interface{})

PrintlnFunc returns a new function that prints the passed arguments as colorized with color.Println().

func (*Color) Set

func (c *Color) Set() *Color

Set sets the SGR sequence.

func (*Color) Sprint

func (c *Color) Sprint(a ...interface{}) string

Sprint is just like Print, but returns a string instead of printing it.

func (*Color) SprintFunc

func (c *Color) SprintFunc() func(a ...interface{}) string

SprintFunc returns a new function that returns colorized strings for the given arguments with fmt.Sprint(). Useful to put into or mix into other string. Windows users should use this in conjunction with color.Output, example:

put := New(FgYellow).SprintFunc()
fmt.Fprintf(color.Output, "This is a %s", put("warning"))

func (*Color) Sprintf

func (c *Color) Sprintf(format string, a ...interface{}) string

Sprintf is just like Printf, but returns a string instead of printing it.

func (*Color) SprintfFunc

func (c *Color) SprintfFunc() func(format string, a ...interface{}) string

SprintfFunc returns a new function that returns colorized strings for the given arguments with fmt.Sprintf(). Useful to put into or mix into other string. Windows users should use this in conjunction with color.Output.

func (*Color) Sprintln

func (c *Color) Sprintln(a ...interface{}) string

Sprintln is just like Println, but returns a string instead of printing it.

func (*Color) SprintlnFunc

func (c *Color) SprintlnFunc() func(a ...interface{}) string

SprintlnFunc returns a new function that returns colorized strings for the given arguments with fmt.Sprintln(). Useful to put into or mix into other string. Windows users should use this in conjunction with color.Output.