ls(1)命令的实现

cpp

#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>

int main(int argc, char *argv[]){
DIR *dp;
struct dirent *dirp;

if(argc != 2){
printf("usage: ls directory_name\n");
exit(1);
}
if((dp = opendir(argv[1])) == NULL){
printf("can't open %s\n", argv[1]);
exit(1);
}
while((dirp = readdir(dp)) != NULL){
printf("%s\n", dirp->d_name);
}
closedir(dp);
exit(0);
}

golang

package main

import (
"fmt"
"os"
)

func main() {
var (
directory_name string
count          int
err            error
)
if len(os.Args) == 1 {
if directory_name, err = os.Getwd(); err != nil {
fmt.Println(err)
os.Exit(1)
}
} else {
directory_name = os.Args[1]
}
f, err := os.Open(directory_name)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
list, err := f.Readdir(-1)
f.Close()
if err != nil {
fmt.Println(err)
os.Exit(1)
}
for _, info := range list {
fmt.Println(info.Name())
}
count = len(list)
fmt.Println("总数:", count)
return
}