I wrote earlier about using Go-binData to package configuration files: Golang contains the Go Embed embed feature, which can replace Go-bindata to embed files into executable binaries. This article will introduce the Go Embed feature through examples, including:

  • For individual files, embedding as is supportedstring 或 []byte
  • For multiple files and folders, embedding is supported as a new file systemembed.FS
  • Underline importembedPackage, call packageinit()The function is initialized
  • use//go:embedDirective to embed, followed by the filename or directory name of the embed
  • Only embedding as is supportedstring,[]byte 和 embed.FSThree types of

The embeddedstring

The basic syntax is very simple, first importing the Embed package, then importing the corresponding file or directory structure into the corresponding variable using the instruction //go: Embed filename. For example, create a file version. TXT in the current directory and enter 0.0.1.

package main

import(_"embed"
    "fmt"
)

//go:embed version.txt
var version string

func main(a) {
    fmt.Printf("version: %q\n", version)
}
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The embedded[]byte

package main

import(_"embed"
    "fmt"
)

//go:embed version.txt
var vb []byte

func main(a) {
    fmt.Printf("version %q\n".string(vb))
}
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The embeddedembed.FS

To embed multiple files or directories, the Go: Embed directive can be written as one or more lines:

package main

import(_"embed"
    "fmt"
)

//go:embed hello.txt world.txt
var f embed.FS

func main(a) {
    data, _ := f.ReadFile("hello.txt")
    fmt.Println(string(data))
}
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There are three main methods for the embed.FS type:

func (f FS) Open(name string) (fs.File, error)

func (f FS) ReadDir(name string) ([]fs.DirEntry, error)

func (f FS) ReadFile(name string) ([]byte, error)
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conclusion

Go Embed embed is awesome, so you don’t need to use Go-bindata to generate extra Go source files.