1 /*
2 Package color is an ANSI color package to output colorized or SGR defined
3 output to the standard output. The API can be used in several way, pick one
4 that suits you.
5 6 Use simple and default helper functions with predefined foreground colors:
7 8 color.Cyan("Prints text in cyan.")
9 10 // a newline will be appended automatically
11 color.Blue("Prints %s in blue.", "text")
12 13 // More default foreground colors..
14 color.Red("We have red")
15 color.Yellow("Yellow color too!")
16 color.Magenta("And many others ..")
17 18 // Hi-intensity colors
19 color.HiGreen("Bright green color.")
20 color.HiBlack("Bright black means gray..")
21 color.HiWhite("Shiny white color!")
22 23 However, there are times when custom color mixes are required. Below are some
24 examples to create custom color objects and use the print functions of each
25 separate color object.
26 27 // Create a new color object
28 c := color.New(color.FgCyan).Add(color.Underline)
29 c.Println("Prints cyan text with an underline.")
30 31 // Or just add them to New()
32 d := color.New(color.FgCyan, color.Bold)
33 d.Printf("This prints bold cyan %s\n", "too!.")
34 35 36 // Mix up foreground and background colors, create new mixes!
37 red := color.New(color.FgRed)
38 39 boldRed := red.Add(color.Bold)
40 boldRed.Println("This will print text in bold red.")
41 42 whiteBackground := red.Add(color.BgWhite)
43 whiteBackground.Println("Red text with White background.")
44 45 // Use your own io.Writer output
46 color.New(color.FgBlue).Fprintln(myWriter, "blue color!")
47 48 blue := color.New(color.FgBlue)
49 blue.Fprint(myWriter, "This will print text in blue.")
50 51 You can create PrintXxx functions to simplify even more:
52 53 // Create a custom print function for convenient
54 red := color.New(color.FgRed).PrintfFunc()
55 red("warning")
56 red("error: %s", err)
57 58 // Mix up multiple attributes
59 notice := color.New(color.Bold, color.FgGreen).PrintlnFunc()
60 notice("don't forget this...")
61 62 You can also FprintXxx functions to pass your own io.Writer:
63 64 blue := color.New(FgBlue).FprintfFunc()
65 blue(myWriter, "important notice: %s", stars)
66 67 // Mix up with multiple attributes
68 success := color.New(color.Bold, color.FgGreen).FprintlnFunc()
69 success(myWriter, don't forget this...")
70 71 Or create SprintXxx functions to mix strings with other non-colorized strings:
72 73 yellow := New(FgYellow).SprintFunc()
74 red := New(FgRed).SprintFunc()
75 76 fmt.Printf("this is a %s and this is %s.\n", yellow("warning"), red("error"))
77 78 info := New(FgWhite, BgGreen).SprintFunc()
79 fmt.Printf("this %s rocks!\n", info("package"))
80 81 Windows support is enabled by default. All Print functions work as intended.
82 However, only for color.SprintXXX functions, user should use fmt.FprintXXX and
83 set the output to color.Output:
84 85 fmt.Fprintf(color.Output, "Windows support: %s", color.GreenString("PASS"))
86 87 info := New(FgWhite, BgGreen).SprintFunc()
88 fmt.Fprintf(color.Output, "this %s rocks!\n", info("package"))
89 90 Using with existing code is possible. Just use the Set() method to set the
91 standard output to the given parameters. That way a rewrite of an existing
92 code is not required.
93 94 // Use handy standard colors.
95 color.Set(color.FgYellow)
96 97 fmt.Println("Existing text will be now in Yellow")
98 fmt.Printf("This one %s\n", "too")
99 100 color.Unset() // don't forget to unset
101 102 // You can mix up parameters
103 color.Set(color.FgMagenta, color.Bold)
104 defer color.Unset() // use it in your function
105 106 fmt.Println("All text will be now bold magenta.")
107 108 There might be a case where you want to disable color output (for example to
109 pipe the standard output of your app to somewhere else). `Color` has support to
110 disable colors both globally and for single color definition. For example
111 suppose you have a CLI app and a `--no-color` bool flag. You can easily disable
112 the color output with:
113 114 var flagNoColor = flag.Bool("no-color", false, "Disable color output")
115 116 if *flagNoColor {
117 color.NoColor = true // disables colorized output
118 }
119 120 You can also disable the color by setting the NO_COLOR environment variable to any value.
121 122 It also has support for single color definitions (local). You can
123 disable/enable color output on the fly:
124 125 c := color.New(color.FgCyan)
126 c.Println("Prints cyan text")
127 128 c.DisableColor()
129 c.Println("This is printed without any color")
130 131 c.EnableColor()
132 c.Println("This prints again cyan...")
133 */
134 package color
135