Go by Example: Embed Directive

`//go:embed` is a compiler directive that allows programs to include arbitrary files/folders in the binary. Read more about go directive here.	package main
If no exported identifiers is directly used from `embed` package, you can add an underscore `_` before the package name. In this example, we simply import it as we need to use the `embed.FS` type from the package.	import ( //_ "embed" "embed" )
Since one file is defined after the directive, the compiler will only include this single file, followed by variable `single_file_string` to access as `string` type.	//go:embed example_folder/single_file.txt var single_file_string string
Here is a similar example but include single file as `[]byte`.	//go:embed example_folder/single_file.txt var single_file_byte []byte
We can also embed multiple files or even folders with wildcard.	//go:embed example_folder/single_file.txt //go:embed example_folder/*.hash var folder_FS embed.FS
	func main() {
Print out content of `example_single_file.txt` as `string`.	print(single_file_string)
Now handle `[]byte`.	print(string(single_file_byte))
Retrieve file(s) matching `*.hash` pattern by reading from variable `folder_FS` first, then print out.	hash_file1 := "example_folder/multi_file1.hash" hash_file2 := "example_folder/multi_file2.hash" hash_content1, _ := folder_FS.ReadFile(hash_file1) hash_content2, _ := folder_FS.ReadFile(hash_file2) print(string(hash_content1)) print(string(hash_content2))
	}

Use these commands to run the example. (Note: due to limitation on go playground, this example can only be run on your local machine.)

$ mkdir -p example_folder
$ echo "hello go" > example_folder/single_file.txt
$ echo "123" > example_folder/multi_file1.hash
$ echo "456" > example_folder/multi_file2.hash

$ go run embed-directive.go
hello go
hello go
123
456

Next example: Testing and Benchmarking.