cubefs
color
Color lets you use colorized outputs in terms of ANSI Escape Codes in Go (Golang). It has support for Windows too! The API can be used in several ways, pick one that suits you.
Install
go get github.com/fatih/color
Examples
Standard colors
// Print with default helper functionscolor.Cyan("Prints text in cyan.")
// A newline will be appended automaticallycolor.Blue("Prints %s in blue.", "text")
// These are using the default foreground colorscolor.Red("We have red")color.Magenta("And many others ..")
Mix and reuse colors
// Create a new color objectc := 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 output (io.Writer)
// Use your own io.Writer outputcolor.New(color.FgBlue).Fprintln(myWriter, "blue color!")
blue := color.New(color.FgBlue)blue.Fprint(writer, "This will print text in blue.")
Custom print functions (PrintFunc)
// Create a custom print function for conveniencered := color.New(color.FgRed).PrintfFunc()red("Warning")red("Error: %s", err)
// Mix up multiple attributesnotice := color.New(color.Bold, color.FgGreen).PrintlnFunc()notice("Don't forget this...")
Custom fprint functions (FprintFunc)
blue := color.New(color.FgBlue).FprintfFunc()blue(myWriter, "important notice: %s", stars)
// Mix up with multiple attributessuccess := color.New(color.Bold, color.FgGreen).FprintlnFunc()success(myWriter, "Don't forget this...")
Insert into noncolor strings (SprintFunc)
// Create SprintXxx functions to mix strings with other non-colorized strings:yellow := color.New(color.FgYellow).SprintFunc()red := color.New(color.FgRed).SprintFunc()fmt.Printf("This is a %s and this is %s.\n", yellow("warning"), red("error"))
info := color.New(color.FgWhite, color.BgGreen).SprintFunc()fmt.Printf("This %s rocks!\n", info("package"))
// Use helper functionsfmt.Println("This", color.RedString("warning"), "should be not neglected.")fmt.Printf("%v %v\n", color.GreenString("Info:"), "an important message.")
// Windows supported too! Just don't forget to change the output to color.Outputfmt.Fprintf(color.Output, "Windows support: %s", color.GreenString("PASS"))
Plug into existing code
// Use handy standard colorscolor.Set(color.FgYellow)
fmt.Println("Existing text will now be in yellow")fmt.Printf("This one %s\n", "too")
color.Unset() // Don't forget to unset
// You can mix up parameterscolor.Set(color.FgMagenta, color.Bold)defer color.Unset() // Use it in your function
fmt.Println("All text will now be bold magenta.")
Disable/Enable color
There might be a case where you want to explicitly disable/enable color output. the
go-isatty
package will automatically disable color output for non-tty output streams
(for example if the output were piped directly to less
).
The color
package also disables color output if the NO_COLOR
environment
variable is set to a non-empty string.
Color
has support to disable/enable colors programmatically both globally and
for single color definitions. 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...")
GitHub Actions
To output color in GitHub Actions (or other CI systems that support ANSI colors), make sure to set color.NoColor = false
so that it bypasses the check for non-tty output streams.
Todo
- Save/Return previous values
- Evaluate fmt.Formatter interface
Credits
- Fatih Arslan
- Windows support via @mattn: colorable
License
The MIT License (MIT) - see LICENSE.md
for more details