struct dir{
    ino_t            d_ino;             //此目录进入点的ino
    ff_t             d_off;             //目录开头到此目录进入点的位移
    signed short int d_reclen;          //d_name的长度，不包含NULL
    unsigned char    d_type;            //d_name的文件类型
    char             d_name[256];       // 文件名    
}  

#include<sys/stat.h>
#include<sys/types.h>

int mkdir(const char* pathname,mode_t mode);
//成功-->0，失败--> -1

int rmdir(const char *pathname);
//成功-->0，失败--> -1

//dir.c
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stst.h>
#include <fcntl.h>

int main(int argc, char **argv)
{
    int sign;
    char pathname[]="/root/yy/temp";
    
    sign=mkdir(pathname,O_RDWR);
    if(sign==0)
        printf("create secceed!\n");
    else
        printf("failed!\n");
        
    sign=rmdir(pathname);
    if(sign==0)
        printf("delete secceed!\n");
    else
        printf("failed!\n");
    
    return 0;
}

#include<sys/types.h>
#include<dirent.h>

DIR* opendir(const chr* name);

struct dirent* readdir(DIR *dir);

int closedir(DIR *dir);

//readdir.c

#include<stdio.h>
#include<sys/types.h>
#include<dirent.h>

int main()
{
   DIR *dir;
   struct dirent *ptr;
   dir=opendir("/root/yy/");
   while((ptr=readdir(dir))!=NULL)
   {
       prinf("%s\n",ptr->d_name);
   }     
   closedir(dir);
   return 0;   
}

#include<sys/types.h>
#include<sys/stat.h>

int chmod(const char *path,mode_t mode)

#include<unistd.h>

char* getcwd(char *buf,size_t size);

//getcwd.c
#include<unistd.h>
#include<stdio.h>

int main()
{
   char buffer[80];
   if(getcwd(buffer,80)!=NULL)
      printf("dir is %s\n",buffer);
   else
     printf("failed!\n");   
   return 0;   
}