ls

open directory;
while(!(end of dir))
{read file info;
}
open directory

 ./myls1  ../ls  ../camke-build-debug

argc=3；
*argv=“./myls1 ”；
*(argv+1) = “ ../ls ”；
*(argv+2) = “  ../camke-build-debug”；

while((pdirent=readdir(pDir)) != NULL)
{if (strcmp(pdirent->d_name, ".") == 0 || strcmp(pdirent->d_name, "..") == 0){continue;}printf("%sn", pdirent->d_name);}

#include<stdio.h>
#include<string.h>
#include<dirent.h>void ls(char *dirpath);int main(int argc, char *argv[])
{if(argc==1)//没有命令行参数时，列出当前目录中的文件和目录列表{ls(".");}else{while(--argc){printf("%s:n",*++argv);ls(*argv);}}return 0;
}void ls(char *dirpath)
{DIR *pDir;struct dirent *pdirent;if((pDir=opendir(dirpath)) == NULL){fprintf(stderr,"ls1:cannot open %sn",dirpath);}else{while((pdirent=readdir(pDir)) != NULL){if (strcmp(pdirent->d_name, ".") == 0 || strcmp(pdirent->d_name, "..") == 0){continue;}printf("%sn", pdirent->d_name);}closedir(pDir);}
}

int stat(const char *file_path, struct stat *buf);
执行成功则返回0，失败返回-1，错误代码存于errno
错误代码:
ENOENT         参数file_name指定的文件不存在
ENOTDIR        路径中的目录存在但却非真正的目
ELOOP          欲打开的文件有过多符号连接问题，上限为16符号连接
EFAULT         参数buf为无效指针，指向无法存在的内存空间
EACCESS        存取文件时被拒绝
ENOMEM         核心内存不足
ENAMETOOLONG   参数file_name的路径名称太长数值

    if (argc==1){printf("Please Enter a path to at least one file");exit(-1);}else{while(--argc){if (0 != stat(*++argv, &file_stat)) //call stat function{perror("stat");exit(-1);}printf("%s:n",*argv);print_file_stat(&file_stat);}}