@iamzcr 还要判断下文件类型，忘了

看到这问题，用 go 的 slice+map 写了下，不知道效率咋样，原理就是按照 ASCII 编码去取 0-9ASCII 编码的范围

package main

import (
"bufio"
"fmt"
"io"
"os"
"strings"
)

func delSlice(slice []byte, dels []byte) []byte {
dMap := make(map[byte]bool)
for _, s := range dels {
dMap[s] = true
}
for i := 0; i < len(slice); i++ {
if _, ok := dMap[slice[i]]; ok {
slice = append(slice[:i], slice[i+1:]...)
i = i - 1
}
}
return slice
}
func ReadLine(fileName string) {
f, err := os.Open(fileName)
if err != nil {
panic(err)
}
buf := bufio.NewReader(f)
for {
line, err := buf.ReadString('\n')
if err != nil {
if err == io.EOF {
break
}
}
line = strings.TrimSpace(line)
slice := make([]byte, 1)
slice = []byte(line)
outSlice := make([]byte, 1)
for i := 0; i < len(slice)-1; i++ {
if slice[i] > 47 && slice[i] <= 58 {
outSlice = append(outSlice, slice[i])
}
}
inSlice := delSlice(slice, outSlice)
str := string(inSlice)
fmt.Println(str)

}
}

func main() {
ReadLine("./test.txt")
}