一 、mkdir的实现。#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>//仿写mkdir命令
//输入的如果是x/y/z;而x并不存在，就会一个一个的创建
//核心是分割字符串int main(int argc,char *argv[])
{argv[1];//对argv[1]进行分割char * p =  strtok(argv[1],"/");int erro = 0;char * path = (char *)malloc(256);strcpy(path,p);printf("%s\n",path);if(access(path,F_OK) != 0){erro = mkdir(path ,0777);if(erro == -1){perror("mkdir");return -1;}}while(1){p = strtok(NULL,"/");if(p == NULL){break ;}sprintf(path,"%s/%s",path,p);printf("%s\n",path);if(access(path,F_OK) == 0){//存在这个目录，不需要创建。
        }else{erro = mkdir(path ,0777);if(erro == -1){perror("mkdir");return -1;}}}return 0;
}ls的实现#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>int main(int argc,char *argv[])
{DIR *dir = opendir(argv[1]);if(NULL == dir){perror("opendir");return ;}//使用路径打开文件。while(1){struct dirent * str_dir = readdir(dir);if(NULL == str_dir){break;}if(strcmp(".",str_dir->d_name) == 0 || 0 == strcmp("..",str_dir->d_name)){break;}printf("%s\n",str_dir->d_name);}return 0;
}拷贝目录#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>//opendir的头文件 //readdir的头文件
#include <sys/stat.h>#include <fcntl.h>//open需要的头文件
#include <string.h>
#include <errno.h>      //errno的头文件
#include <stdlib.h>
#include <unistd.h>    //close的头文件int main(int argc,char *argv[])
{//打印一个文件夹下的各种文件。/*DIR * folder = opendir(argv[1]);if(NULL == folder){perror("open");return -1;}while(1){struct dirent * dir = readdir(folder);if(NULL == dir){break;}printf("%s\n",dir->d_name);}*/if(access(argv[2],F_OK) == -1){mkdir(argv[2],0777);}//如果文件不存在，就创建一个文件。swap(argv[1],argv[2]);return 0;
}int swap(char * source,char *destination)
{DIR * sourDir = opendir(source);if(source == NULL){perror("openDir");return -1;}//遍历目录，如果发现是普通文件就直接复制，目录文件就递归调用while(1){struct dirent *dir = readdir(sourDir);if(NULL == dir){break;}/*if( 0 == strncmp(dir->d_name,".",1)){continue;}*/if(DT_DIR == dir->d_type){//去除..和.if(strcmp(dir->d_name,"..") == 0 || strcmp(dir->d_name,".") == 0){//printf("%s\n\n",dir->d_name);continue;}char sourceDir[256] = {'\0'};char destinationDir[256] = {'\0'};sprintf(sourceDir,"%s/%s",source,dir->d_name);sprintf(destinationDir,"%s/%s",destination,dir->d_name);if(access(destinationDir,F_OK) == -1){int ret = mkdir(destinationDir,0777);if(ret == -1){printf("出错%s\n",destinationDir);perror("mkdir");return -1;}}    swap(sourceDir,destinationDir);}else{//需要使用一个copy的命令命令char sourceDir[256] = {'\0'};char destinationDir[256] = {'\0'};sprintf(sourceDir,"%s/%s",source,dir->d_name);sprintf(destinationDir,"%s/%s",destination,dir->d_name);printf("%s\n",sourceDir);printf("%s\n",destinationDir);copy(sourceDir,destinationDir);//复制文件。
        }}return 1;
}//拷贝一个文件，如果成功就会返回1，否则就会返回-1.
int copy(char * p1 ,char * p2)
{int fd = -1 ;int fd2 = -1;fd = open(p1,O_RDONLY);if(-1 == fd){perror("open1");//exit(EXIT_FAILURE);return -1;}fd2 = open(p2,O_WRONLY|O_CREAT,0664);if(-1 == fd2){perror("open2");//exit(EXIT_FAILURE);return -1;}while(1){char x[256];ssize_t ret =-1;ret = read(fd,x,256);if(ret == -1){perror("read");return -1;}if(ret == 0){break;}ret = write(fd2,x,ret);if(ret == -1){perror("write");return -1;}}close(fd);close(fd2);return 1;
}