golang 读写文件内容(备份)

来源：互联网发布：陈都灵章泽天知乎编辑：程序博客网时间：2024/06/08 01:06

以下是读取文件内容

package mainimport (    "bufio"    "fmt"    "io"    "os"    "strings")func main() {    fh, ferr := os.Open("d:\\n.txt")    if ferr != nil {        fmt.Printf("An error occurred on opening the inputfile\n" +            "Does the file exist?\n" +            "Have you got acces to it?\n")        return     }    defer fh.Close()    inputread := bufio.NewReader(fh)    for {        input, ferr := inputread.ReadString('\n')        if ferr == io.EOF {            return        }        fmt.Println(strings.TrimSpace(input))    }}

读取gzip格式文件：

package mainimport ("bufio""compress/gzip""fmt""os")func main() {fName := "MyFile.gz"var r *bufio.Readerfi, err := os.Open(fName)if err != nil {fmt.Fprintf(os.Stderr, "%v, Can't open %s: error: %s\n", os.Args[0],fName, err)os.Exit(1)}fz, err := gzip.NewReader(fi)if err != nil {r = bufio.NewReader(fi)//解压失败（还是读取原来文件）gz文件还是读取原始文件} else {r = bufio.NewReader(fz)//解压成功后读取解压后的文件}for {line, err := r.ReadString('\n')if err != nil {fmt.Println("Done reading file")os.Exit(0)}fmt.Println(line)}}

写文件:

package mainimport ("bufio""fmt""os")func main() {outputFile, outputError := os.OpenFile("output.dat",os.O_WRONLY|os.O_CREATE, 0666)//0666是标准的权限掩码,关于打开标识看下面if outputError != nil {fmt.Printf("An error occurred with file creation\n")return}defer outputFile.Close()outputWriter := bufio.NewWriter(outputFile)outputString := "hello world!\n"for i := 0; i < 10; i++ {outputWriter.WriteString(outputString)}outputWriter.Flush()}

os.O_RDONLY : the read flag for read-only access
os.WRONLY : the write flag for write-only access
os.O_CREATE : the create flag: create the file if it doesn’t exist
os.O_TRUNC : the truncate flag: truncate to size 0 if the file already exists