ls命令的简要实现

<span style="font-size:14px;">#include<stdio.h>#include<stdlib.h>#include<dirent.h>int main(int argc,char *argv[]){DIR *dp;struct dirent *dirp;if(argc != 2){printf("suage: 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);}</span>

1. 命令行的第一个参数argv[1]作为要列出的各个目录项的目录名

2. opendir函数返回指向DIR结构的指针

3. readdir函数用于读取每个目录项

4.函数exit用于终止程序，参数0表示正常结束，而参数1～255表示出错

5.运行例程：$./a.out /dev/