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248 lines
7.1 KiB
248 lines
7.1 KiB
#define __LIBRARY__
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <sys/types.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <asm/segment.h>
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#include <sys/stat.h>
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#define BUF_MAX 256
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char * sys_getcwd(char * buf, size_t size)
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{
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char temp[BUF_MAX], buff[BUF_MAX];
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int flag,len;
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struct m_inode *current_inode = current->pwd;
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struct m_inode *root_inode = current->root;
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//超级块
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struct super_block *super_b = (struct super_block *)bread(current_inode->i_dev,1);//超级块
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//首先找到索引节点基址
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struct m_inode *base_inode = super_b->s_isup;
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//printk("base_inode:%d\n",base_inode->i_num);
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struct m_inode *father_inode;
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struct dir_entry *father_entrys;
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struct dir_entry *current_entrys;
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int i;
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while(1)
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{
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//指向当前目录下的某一目录项
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current_entrys = (struct dir_entry *)bread(current_inode->i_dev,current_inode->i_zone[0])->b_data;
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int current_entrys_num = current_inode->i_size/sizeof(struct dir_entry);//当前目录的目录项数量
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//在当前目录中找到父目录的目录项
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flag = 0;
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for(i=0;i<current_entrys_num;i++){
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if(!strcmp((current_entrys+i)->name,"..")){//通过**目录项的名字**搜索父目录
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//printk("father_dir:%s\tnode_num%d\n",(current_entrys+i)->name,(current_entrys+i)->inode);
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flag = 1;
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father_inode = iget(current_inode->i_dev,(current_entrys + i)->inode);//父目录i节点
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break;
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}
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}
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if(!flag) {
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printk("Sorry,No ..\n");
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return NULL;
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}
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father_entrys = (struct dir_entry *)bread(father_inode->i_dev,father_inode->i_zone[0])->b_data;
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int father_entrys_num = father_inode->i_size/sizeof(struct dir_entry);//父目录的目录项数量
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//在父目录中寻找当前目录的目录项
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flag = 0;
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for(i=0;i<father_entrys_num;i++){
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if((father_entrys+i)->inode == current_inode->i_num){//通过**目录项的i节点序号**搜索子目录
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//printk("current_dir:%s\tnode_num%d\n",(father_entrys+i)->name,(father_entrys+i)->inode);
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memset(temp, 0, sizeof(temp));
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strcat(temp,"/");
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strcat(temp,(father_entrys+i)->name);
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strcat(temp,buff);
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strncpy(buff,temp,BUF_MAX);
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flag = 1;
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break;
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}
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}
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if(!flag){
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printk("Sorry, Current dircory is lost\n");
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return NULL;
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}
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if(root_inode->i_num == father_inode->i_num)
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break;
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current_inode = father_inode;
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}
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//strcat(buff,'\0');
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//将位于核心段的buff拷贝到位于用户段的buf
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len = 0;
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while(buff[len++]);//计算cwd字符串长度
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//printk("cwd:%s\tlen:%d\n",buff,len);
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for(i=0;i<len;i++){
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put_fs_byte(buff[i],buf+i);
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}
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put_fs_byte('\0',buf+len);
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return buf;
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}
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/////////////////////////////////////////////////////////////////////////
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// typedef struct
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// {
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// int dd_fd; /* file descriptor */
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// int dd_loc; /* offset in block */
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// int dd_size; /* amount of valid data */
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// char *dd_buf; /* -> directory block */
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// } DIR; /* stream data from opendir() */
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// struct direct {
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// ino_t d_ino;
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// char d_name[NAME_MAX];
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// };
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// static struct linux_dirent result;
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// _syscall3(int,read,int,fildes, char *, buf, off_t ,count)
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// struct linux_dirent * readdir(DIR * dir)
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// {
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// struct direct * ptr;
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// if (!dir) {
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// errno = EBADF;
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// return NULL;
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// }
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// if (!dir->dd_buf)
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// if (!(dir->dd_buf = malloc(DIRBUF)))
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// return NULL;
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// else
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// dir->dd_size = dir->dd_loc = 0;
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// while (1) {
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// if (dir->dd_size <= dir->dd_loc) {
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// dir->dd_loc = 0;
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// dir->dd_size = read(dir->dd_fd,dir->dd_buf,DIRBUF);
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// }
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// if (dir->dd_size <= 0)
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// return NULL;
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// ptr = (struct direct *) (dir->dd_loc + dir->dd_buf);
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// dir->dd_loc += sizeof (*ptr);
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// if (!ptr->d_ino)
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// continue;
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// result.d_ino = ptr->d_ino;
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// strncpy(result.d_name,ptr->d_name,NAME_MAX);
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// result.d_name[NAME_MAX] = 0;
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// result.d_reclen = strlen(result.d_name);
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// return &result;
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// }
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// }
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// int closedir(DIR * dir)
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// {
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// int fd;
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// if (!dir) {
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// errno = EBADF;
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// return -1;
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// }
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// fd = dir->dd_fd;
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// free(dir->dd_buf);
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// free(dir);
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// return close(fd);
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// }
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// _syscall2(int ,fstat,int ,fildes, struct stat *,stat_buf)//fstat利用文件句柄(描述符)来获取信息
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// DIR * opendir(const char * dirname)
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// {
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// int fd;
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// struct stat stat_buf;
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// DIR * ptr;
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// if ((fd = open(dirname,O_RDONLY))<0)
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// return NULL;
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// if (fstat(fd,&stat_buf)<0 ||
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// !S_ISDIR(stat_buf.st_mode) ||
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// !(ptr=malloc(sizeof(*ptr)))) {
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// close(fd);
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// return NULL;
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// }
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// memset(ptr,0,sizeof(*ptr));
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// ptr->dd_fd = fd;
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// return ptr;
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// }
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// _syscall2(int ,stat,const char *,filename, struct stat *,stat_buf)//stat利用文件名来获取信息
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// _syscall1(int,chdir,const char *, filename)//chdir跳转至目录名
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// char * sys_getcwd(char * buf, size_t size){
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// char path[BUF_MAX], cwd[BUF_MAX], buff[BUF_MAX];
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// DIR *dirp;
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// struct linux_dirent *dp;
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// struct stat sb, sb_d, sb_1;
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// dev_t dev;
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// ino_t ino;
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// int i;
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// while(1){
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// //获取当前目录的文件信息
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// if(stat(".", &sb) == -1)
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// /*exit("stat");*/
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// dev = sb.st_dev;
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// ino = sb.st_ino;//节点信息
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// //获取父目录的对应的目录流和父目录的文件信息
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// if((dirp = opendir("..")) == NULL)
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// /*errExit("opendir");*/
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// if(stat("..", &sb_1) == -1)
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// /*exit("stat");*/
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// //判断当前目录是否与父目录相同
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// if(sb_1.st_dev == dev && sb_1.st_ino == ino)//索引节点号相同 && 设备号相同 ==>目录文件相同
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// break;
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// errno = 0;
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// //在父目录对应的目录流读取条目
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// while((dp = readdir(dirp)) != NULL){
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// /* snprintf(path, BUF_MAX, "../%s", dp->d_name);*/
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// printk("../%s", dp->d_name);
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// memcpy(path,dp->d_name,BUF_MAX);
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// printk("../%s", "usr");
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// if(stat(path, &sb_d) == -1)
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// /* exit("stat");*/
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// //得到当前目录对应的条目并将目录逐渐完善
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// if(dev == sb_d.st_dev && ino == sb_d.st_ino){
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// memset(cwd, 0, sizeof(cwd));
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// if(strcat(cwd, "/") == NULL)
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// /* exit("strcat");*/
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// if(strcat(cwd, dp->d_name) == NULL)
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// /* exit("strcat");*/
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// if(strcat(cwd, buf) == NULL)
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// /* exit("strcat");*/
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// if(strncpy(buf, cwd, BUF_MAX) == NULL)
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// /* exit("strncpy");*/
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// break;
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// }
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// }
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// if(dp == NULL && errno != 0)
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// /*exit("readdir");*/
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// closedir(dirp);
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// chdir(".."); //改变当前目录
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// }
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// //printk("%s\n",buff);
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// /*
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// for(i=0;i<10;i++)
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// put_fs_byte(*(buff+i), (buf+i));
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// put_fs_byte('\0', (buf+i));
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// */
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// return buf;
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// }
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