(1)如何打开一个文件并读取:

    1. file, err := os.Open("input.dat")
    2. if err != nil {
    3. fmt.Printf("An error occurred on opening the inputfile\n" +
    4. "Does the file exist?\n" +
    5. "Have you got acces to it?\n")
    6. return
    7. }
    8. defer file.Close()
    9. iReader := bufio.NewReader(file)
    10. for {
    11. str, err := iReader.ReadString('\n')
    12. if err != nil {
    13. return // error or EOF
    14. }
    15. fmt.Printf("The input was: %s", str)
    16. }

    (2)如何通过切片读写文件:

    1. func cat(f *file.File) {
    2. const NBUF = 512
    3. var buf [NBUF]byte
    4. for {
    5. switch nr, er := f.Read(buf[:]); true {
    6. case nr < 0:
    7. fmt.Fprintf(os.Stderr, "cat: error reading from %s: %s\n",
    8. f.String(), er.String())
    9. os.Exit(1)
    10. case nr == 0: // EOF
    11. return
    12. case nr > 0:
    13. if nw, ew := file.Stdout.Write(buf[0:nr]); nw != nr {
    14. fmt.Fprintf(os.Stderr, "cat: error writing from %s: %s\n",
    15. f.String(), ew.String())
    16. }
    17. }
    18. }
    19. }