package lineprefix

import "github.com/abiosoft/lineprefix"

Package lineprefix provides a `io.Writer` wrapper with line prefix and color customizations.

Static Prefix

prefix := lineprefix.Prefix("app |")
writer := lineprefix.New(prefix)

fmt.Fprintln(writer, "hello world")

Dynamic Prefix

now := func() string { return time.Now().UTC().Format("2006-01-02 15:04:05") }
prefix := lineprefix.PrefixFunc(now)
writer := lineprefix.New(prefix)

for i := 0; i<3; i++ {
    fmt.Fprintln(writer, "hello world")
    time.Sleep(time.Second)
}

Colors can be added with github.com/faith/color

A prefix with blue text on white background

blue := color.New(color.FgBlue, color.BgWhite).SprintFunc()
prefix := lineprefix.Prefix(blue("app"))
writer := lineprefix.New(prefix)

fmt.Fprintln(writer, "this outputs blue on white prefix text")

A blue colored output

blue := color.New(color.FgBlue)
option := lineprefix.Color(blue)
writer := lineprefix.New(option)

fmt.Fprintln(writer, "this outputs blue color text")

Index ¶

• func New(options ...Option) io.WriteCloser
• type Option
• func Color(c *color.Color) Option
• func Prefix(s string) Option
• func PrefixFunc(f func() string) Option
• func RenderEscaped(b bool) Option
• func Writer(w io.Writer) Option

Functions ¶

func New ¶

func New(options ...Option) io.WriteCloser

New creates a new lineprefix writer with options.

Types ¶

type Option ¶

type Option interface {
	// contains filtered or unexported methods
}

Option is the configuration option for a new instance of lineprefix writer.

func Color ¶

func Color(c *color.Color) Option

Color sets the colour for the line outputs, excluding the prefix.

func Prefix ¶

func Prefix(s string) Option

Prefix sets the prefix to use. Can be called multiple times to set multiple prefixes.

func PrefixFunc ¶

func PrefixFunc(f func() string) Option

PrefixFunc is like prefix but with the ability to make it dynamic. Can be called multiple times to set multiple prefixes.

func RenderEscaped ¶

func RenderEscaped(b bool) Option

RenderEscaped (if true) enables the rendering of escaped whitespace characters. e.g. `\\t` appears as tab instead of `\t`, `\\n` appears as newline instead of `\n` e.t.c.

func Writer ¶

func Writer(w io.Writer) Option

Writer sets the writer to use. The default writer is os.Stdout.

Source Files ¶

color.go doc.go lineprefix.go

Directories ¶