If you've ever worked on a CLI application before, you probably know the struggle of working with ANSI escape codes. Often, you just want to quickly apply a style to a string, but you either have to interrupt your workflow to look up the escape sequence and codes, or you have to import a large package that does more than you need.
The ansi package is extremely lightweight 🪶 and has no external
dependencies 📦 It allows you to quickly apply styles to strings using
human-readable style blocks. Because the styles are defined inline,
there is no need to call a function for each style, making it easy to
apply/reset multiple styles to a single string.
With ansi, the mess at the top of this page becomes: 
Strings are formatted using "style blocks". A style block is delimited by square
brackets ([]) and contains a list of styles separated by colons. For example,
the style block [red:bold] applies the red and bold styles to any text
following the block.
Styles can be reset by using the corresponding reset code or by using the global
reset ([/]) to reset all styles.
import "github.com/pd93/ansi"
str := ansi.Parse("This is a [red:bold]red and bold[/] string")
fmt.Println(str)
// Or use the provided fmt package function wrappers
ansi.Println("This is a [red:bold]red and bold[/] string")If you need to print a literal string that conflicts with a valid style block,
you can escape the block by prepending it with a backslash (\). For example,
\[red] will print [red] instead of applying the red style.
// Note that we need to escape the escaping backslash otherwise it will be removed.
ansi.Println("This is \\[red:bold]an escaped style block\\[/]")
// We can avoid this in most situations by using a raw string (backticks) instead:
ansi.Println(`This is \[red:bold]an escaped style block\[/]`)For more info, check out the style reference below or take a look at our examples.
| Code | ANSI Code | Description |
|---|---|---|
/ |
0 |
Resets all styles |
| Code | ANSI Code | Description |
|---|---|---|
bold |
1 |
Sets the font weight to bold |
faint, dim |
2 |
Sets the text brightness to its faint/dim variant * |
italic |
3 |
Sets the font style to italic |
underline |
4 |
Sets the text decoration to underline |
blink |
5 |
Sets the text to blink in and out |
invert |
7 |
Inverts the foreground and background colors |
hidden |
8 |
Sets the text to be hidden |
strike |
9 |
Sets the text decoration to line-through |
*
faintanddimdo not work when using 8-bit (256) or 24-bit (RGB) color modes.
| Code | ANSI Code | Description |
|---|---|---|
/bold |
22 |
Resets the font weight ** |
/faint, /dim |
22 |
Resets the text brightness ** |
/italic |
23 |
Resets the font style |
/underline |
24 |
Resets the underline text decoration |
/blink |
25 |
Stops the text from blinking |
/invert |
27 |
Resets the text inversion |
/hidden |
28 |
Resets the text visibility |
/strike |
29 |
Resets the line-through text decoration |
** The
/bold,/faint, and/dimcodes all equal because they share an ANSI code. This means it is not possible to reset them individually.
| Code | ANSI Code | Description |
|---|---|---|
black |
30 |
Sets the text foreground to black |
red |
31 |
Sets the text foreground to red |
green |
32 |
Sets the text foreground to green |
yellow |
33 |
Sets the text foreground to yellow |
blue |
34 |
Sets the text foreground to blue |
magenta |
35 |
Sets the text foreground to magenta |
cyan |
36 |
Sets the text foreground to cyan |
white |
37 |
Sets the text foreground to white |
R,G,B |
38;2;R;G;B |
Sets the text foreground to the given 24-bit (RGB) color |
N |
38;5;N |
Sets the text foreground to the given 8-bit (256) color |
/fg |
39 |
Resets the text foreground to the default color |
| Code | ANSI Code | Description |
|---|---|---|
bg-black |
40 |
Sets the text background to black |
bg-red |
41 |
Sets the text background to red |
bg-green |
42 |
Sets the text background to green |
bg-yellow |
43 |
Sets the text background to yellow |
bg-blue |
44 |
Sets the text background to blue |
bg-magenta |
45 |
Sets the text background to magenta |
bg-cyan |
46 |
Sets the text background to cyan |
bg-white |
47 |
Sets the text background to white |
bg-R,G,B |
48;2;R;G;B |
Sets the text background to the given 24-bit (RGB) color |
bg-N |
48;5;N |
Sets the text background to the given 8-bit (256) color |
/bg |
49 |
Resets the text background to the default color |