go语言对文件按照指定块大小进行分割的方法
2018-09-21 18:56
本文实例讲述了go语言对文件按照指定块大小进行分割的方法。分享给大家供大家参考。具体如下:
复制代码 代码如下:
import (
//bufio
flag
fmt
io
os
)
import strconv
var infile *string = flag.String(f, Null, please input a file name or dir.)
var size *string = flag.String(s, 0, please input a dst file size.)
//func dataCopy(file *os.File, file *os.File)
func SplitFile(file *os.File, size int) {
finfo, err := file.Stat()
if err != nil {
fmt.Println(get file info failed:, file, size)
}
fmt.Println(finfo, size)
//每次最多拷贝1m
bufsize := 1024 * 1024
if size < bufsize {
bufsize = size
}
buf := make([]byte, bufsize)
num := (int(finfo.Size()) + size - 1) / size
fmt.Println(num, len(buf))
for i := 0; i < num; i++ {
copylen := 0
newfile, err1 := os.Create(newfilename)
if err1 != nil {
fmt.Println(failed to create file, newfilename)
} else {
fmt.Println(create file:, newfilename)
}
for copylen < size {
n, err2 := file.Read(buf)
if err2 != nil && err2 != io.EOF {
fmt.Println(err2, failed to read from:, file)
break
}
if n <= 0 {
break
}
//fmt.Println(n, len(buf))
//写文件
w_buf := buf[:n]
newfile.Write(w_buf)
copylen += n
}
}
return
}
func main() {
flag.Parse()
if *infile == Null {
fmt.Println(no file to input)
return
}
file, err := os.Open(*infile)
if err != nil {
fmt.Println(failed to open:, *infile)
}
defer file.Close()
size, _ := strconv.Atoi(*size)
SplitFile(file, size*1024)
}
希望本文所述对大家的Go语言程序设计有所帮助。