A lightweight Go library for terminal text colorization using ANSI escape codes.

• Simple and intuitive API
• Support for multiple color schemes (basic, bright, background colors)
• Memory efficient with sync.Pool buffer management
• High-performance operations with zero external dependencies
• Compatible with any io.Writer interface

go get github.com/yanun0323/colorize

package main

import (
    "fmt"
    "strings"

    "github.com/yanun0323/colorize"
)

func main() {
    // Basic string colorization
    fmt.Println(colorize.String(colorize.ColorRed, "Error message"))
    fmt.Println(colorize.Sprint(colorize.ColorGreen, "Success:", " operation completed"))
    fmt.Println(colorize.Sprintf(colorize.ColorBlue, "User %s logged in", "john"))

    // Write to buffer
    var buf strings.Builder
    colorize.Fprint(&buf, colorize.ColorYellow, "Warning:", " low disk space")
    colorize.Fprintf(&buf, colorize.ColorCyan, " Available: %d%%", 15)
    fmt.Print(buf.String())

    // Remove ANSI codes
    coloredText := colorize.String(colorize.ColorRed, "Error")
    plainText := colorize.Reset(coloredText)
    fmt.Println(plainText) // Output: "Error" (without colors)
}

For maximum performance, you can build the colored output by appending to a pre-allocated byte slice:

buf := make([]byte, 0, 4<<10) // allocate enough size
buf = append(buf, colorize.ColorRed...)
buf = append(buf, "Hello, World"...)
buf = append(buf, colorize.ColorReset...)

• String(c Color, str ...string) string - Colorize multiple strings
• Sprint(c Color, args ...any) string - Colorize with fmt.Sprint behavior
• Sprintf(c Color, format string, args ...any) string - Colorize with formatting
• Fprint(w io.Writer, c Color, args ...any) (int, error) - Write colorized text to writer
• Fprintf(w io.Writer, c Color, format string, args ...any) (int, error) - Write formatted colorized text
• Reset(s string) string - Remove ANSI escape codes from string

Benchmarks (darwin/arm64, Apple M2).

BenchmarkColorizeString-8       39335316                30.01 ns/op           24 B/op          1 allocs/op
BenchmarkColorizeReset-8        25729447                45.86 ns/op           16 B/op          1 allocs/op
BenchmarkColorizeSprint-8       14059197                80.54 ns/op          136 B/op          3 allocs/op
BenchmarkColorizeSprintf-8      14723767                81.97 ns/op          136 B/op          3 allocs/op
BenchmarkColorizeFprint-8       36809578                33.07 ns/op            0 B/op          0 allocs/op
BenchmarkColorizeFprintf-8      34705401                35.12 ns/op            0 B/op          0 allocs/op
BenchmarkColorizeAppend-8      634096282                 1.89 ns/op            0 B/op          0 allocs/op

This project is licensed under the MIT License - see the LICENSE file for details.