golang 實現文件拷貝的2種方式
阿新 • • 發佈：2018-01-25
ror open 拷貝 string str fmt 2種 urn led
package main
import (
"fmt"
"io"
"os"
"path/filepath"
"strconv"
)
var BUFFERSIZE int64
func Copy1(src, dst string, BUFFERSIZE int64) error {
sourceFileStat, err := os.Stat(src)
if err != nil {
return err
}
if !sourceFileStat.Mode().IsRegular() {
return fmt.Errorf("%s is not a regular file", src)
}
source, err := os.Open(src)
if err != nil {
return err
}
defer source.Close()
_, err = os.Stat(dst)
if err == nil {
return fmt.Errorf("file %s already exists", dst)
}
destination, err := os.Create(dst)
if err != nil {
return err
}
defer destination.Close()
if err != nil {
panic(err)
}
buf := make([]byte, BUFFERSIZE)
for {
n, err := source.Read(buf)
if err != nil && err != io.EOF {
return err
}
if n == 0 {
break
}
if _, err := destination.Write(buf[:n]); err != nil {
return err
}
}
return err
}
func Copy(src, dst string) (int64, error) {
sourceFileStat, err := os.Stat(src)
if err != nil {
return 0, err
}
if !sourceFileStat.Mode().IsRegular() {
return 0, fmt.Errorf("%s is not a regular file", src)
}
source, err := os.Open(src)
if err != nil {
return 0, err
}
defer source.Close()
destination, err := os.Create(dst)
if err != nil {
return 0, err
}
defer destination.Close()
nBytes, err := io.Copy(destination, source)
return nBytes, err
}
func main() {
if len(os.Args) != 4 {
fmt.Printf("usage: %s source destination BUFFERSIZE\n",
filepath.Base(os.Args[0]))
os.Exit(1)
}
source := os.Args[1]
destination := os.Args[2]
BUFFERSIZE, _ = strconv.ParseInt(os.Args[3], 10, 64)
fmt.Printf("Copying %s to %s\n", source, destination)
err := Copy1(source, destination, BUFFERSIZE)
if err != nil {
fmt.Printf("File copying failed: %q\n", err)
}
}golang 實現文件拷貝的2種方式