理解io/ioutil in go

• package ioutil

  Package ioutil implements some I/O utility functions.

• Variables

  • Discard is an io.Writer on which all Write calls succeed without doing anything.

    var Discard io.Writer = devNull(0)
    

• Functions

  • ReadFile

    func ReadFile(filename string) ([]byte, error)

    ReadFile reads the file named by filename and returns the contents.

    A successful call returns err == nil, not err==EOF.

    Because ReadFile reads the whole file, it does not treat an EOF from Read as an error to be reported.

    package main
    import (
    	"fmt"
        "io/ioutil"
        "log"
    )
    
    func main(){
            
            
        content, err := ioutil.ReadFile("testdata/hello")
        if err != nil {
            
            
            log.Fatal(err)
        }
        
        fmt.Printf("File contents: %s", content)
    }