diff --git a/getcwd.c b/getcwd.c
new file mode 100644
index 0000000..6d5d1ba
--- /dev/null
+++ b/getcwd.c
@@ -0,0 +1,248 @@
+#define __LIBRARY__
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/segment.h>
+#include <sys/stat.h>
+
+
+
+
+#define BUF_MAX 256
+char * sys_getcwd(char * buf, size_t size)
+{	
+	char temp[BUF_MAX], buff[BUF_MAX];
+	int flag,len;
+	struct m_inode *current_inode = current->pwd;
+	struct m_inode *root_inode = current->root;
+	//超级块
+	struct super_block *super_b = (struct super_block *)bread(current_inode->i_dev,1);//超级块
+	//首先找到索引节点基址
+	struct m_inode *base_inode  = super_b->s_isup;
+	//printk("base_inode:%d\n",base_inode->i_num);
+	struct m_inode *father_inode;
+	struct dir_entry *father_entrys;
+	struct dir_entry *current_entrys;
+	int i;
+	while(1)
+	{
+		//指向当前目录下的某一目录项
+		current_entrys =  (struct dir_entry *)bread(current_inode->i_dev,current_inode->i_zone[0])->b_data;
+		int current_entrys_num = current_inode->i_size/sizeof(struct dir_entry);//当前目录的目录项数量
+		//在当前目录中找到父目录的目录项
+		flag = 0;
+		for(i=0;i<current_entrys_num;i++){
+			if(!strcmp((current_entrys+i)->name,"..")){//通过**目录项的名字**搜索父目录
+				//printk("father_dir:%s\tnode_num%d\n",(current_entrys+i)->name,(current_entrys+i)->inode);
+				flag = 1;
+				father_inode = iget(current_inode->i_dev,(current_entrys + i)->inode);//父目录i节点
+				break;
+			}
+		}
+		if(!flag) {
+			printk("Sorry,No ..\n");
+			return NULL;
+		}
+		
+		father_entrys = (struct dir_entry *)bread(father_inode->i_dev,father_inode->i_zone[0])->b_data;
+		int father_entrys_num = father_inode->i_size/sizeof(struct dir_entry);//父目录的目录项数量
+		//在父目录中寻找当前目录的目录项
+		flag = 0;
+		for(i=0;i<father_entrys_num;i++){
+			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
+				//printk("current_dir:%s\tnode_num%d\n",(father_entrys+i)->name,(father_entrys+i)->inode);
+				memset(temp, 0, sizeof(temp));
+				strcat(temp,"/");
+				strcat(temp,(father_entrys+i)->name);
+				strcat(temp,buff);
+				strncpy(buff,temp,BUF_MAX);
+				flag = 1;
+				break;
+			}
+		}
+		if(!flag){
+			printk("Sorry, Current dircory is lost\n");
+			return NULL;
+		}	
+		if(root_inode->i_num == father_inode->i_num)
+			break;
+		current_inode = father_inode;
+	}
+	//strcat(buff,'\0');
+	//将位于核心段的buff拷贝到位于用户段的buf
+	len = 0;
+	while(buff[len++]);//计算cwd字符串长度
+	//printk("cwd:%s\tlen:%d\n",buff,len);
+	for(i=0;i<len;i++){
+		put_fs_byte(buff[i],buf+i);
+	}
+	put_fs_byte('\0',buf+len);
+	return buf;
+}
+
+
+
+
+
+
+
+
+
+
+/////////////////////////////////////////////////////////////////////////
+// typedef struct
+// 	{
+// 	int	dd_fd;			/* file descriptor */
+// 	int	dd_loc;			/* offset in block */
+// 	int	dd_size;		/* amount of valid data */
+// 	char	*dd_buf;	/* -> directory block */
+// 	}	DIR;			    /* stream data from opendir() */
+
+// struct direct {
+// 	ino_t d_ino;
+// 	char d_name[NAME_MAX];
+// };
+
+// static struct linux_dirent result;
+// _syscall3(int,read,int,fildes, char *, buf, off_t ,count)
+// struct linux_dirent * readdir(DIR * dir)
+// {
+// 	struct direct * ptr;
+
+// 	if (!dir) {
+// 		errno = EBADF;
+// 		return NULL;
+// 	}
+// 	if (!dir->dd_buf)
+// 		if (!(dir->dd_buf = malloc(DIRBUF)))
+// 			return NULL;
+// 		else 
+// 			dir->dd_size = dir->dd_loc = 0;
+// 	while (1) {
+// 		if (dir->dd_size <= dir->dd_loc) {
+// 			dir->dd_loc = 0;
+// 			dir->dd_size = read(dir->dd_fd,dir->dd_buf,DIRBUF);
+// 		}
+// 		if (dir->dd_size <= 0)
+// 			return NULL;
+// 		ptr = (struct direct *) (dir->dd_loc + dir->dd_buf);
+// 		dir->dd_loc += sizeof (*ptr);
+// 		if (!ptr->d_ino)
+// 			continue;
+// 		result.d_ino = ptr->d_ino;
+// 		strncpy(result.d_name,ptr->d_name,NAME_MAX);
+// 		result.d_name[NAME_MAX] = 0;
+// 		result.d_reclen = strlen(result.d_name);
+// 		return &result;
+// 	}
+// }
+
+// int closedir(DIR * dir)
+// {
+// 	int fd;
+
+// 	if (!dir) {
+// 		errno = EBADF;
+// 		return -1;
+// 	}
+// 	fd = dir->dd_fd;
+// 	free(dir->dd_buf);
+// 	free(dir);
+// 	return close(fd);
+// }
+
+// _syscall2(int ,fstat,int ,fildes, struct stat *,stat_buf)//fstat利用文件句柄(描述符)来获取信息
+// DIR * opendir(const char * dirname)
+// {
+// 	int fd;
+// 	struct stat stat_buf;
+// 	DIR * ptr;
+
+// 	if ((fd = open(dirname,O_RDONLY))<0)
+// 		return NULL;
+// 	if (fstat(fd,&stat_buf)<0 ||
+// 	    !S_ISDIR(stat_buf.st_mode) ||
+// 	    !(ptr=malloc(sizeof(*ptr)))) {
+// 		close(fd);
+// 		return NULL;
+// 	}
+// 	memset(ptr,0,sizeof(*ptr));
+// 	ptr->dd_fd = fd;
+// 	return ptr;
+// }
+
+// _syscall2(int ,stat,const char *,filename, struct stat *,stat_buf)//stat利用文件名来获取信息
+// _syscall1(int,chdir,const char *, filename)//chdir跳转至目录名
+// char * sys_getcwd(char * buf, size_t size){
+    
+//     char path[BUF_MAX], cwd[BUF_MAX], buff[BUF_MAX];
+//     DIR *dirp;
+//     struct linux_dirent *dp;
+//     struct stat sb, sb_d, sb_1;
+//     dev_t dev;
+//     ino_t ino;
+//     int i;
+
+//     while(1){
+//         //获取当前目录的文件信息
+//         if(stat(".", &sb) == -1)
+//             /*exit("stat");*/
+//         dev = sb.st_dev;
+//         ino = sb.st_ino;//节点信息
+        
+//         //获取父目录的对应的目录流和父目录的文件信息
+//         if((dirp = opendir("..")) == NULL)
+//             /*errExit("opendir");*/
+//         if(stat("..", &sb_1) == -1)
+//             /*exit("stat");*/
+
+//         //判断当前目录是否与父目录相同
+//         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
+//             break;
+        
+//         errno = 0;
+        
+//         //在父目录对应的目录流读取条目
+//         while((dp = readdir(dirp)) != NULL){
+//            /* snprintf(path, BUF_MAX, "../%s", dp->d_name);*/
+//             printk("../%s", dp->d_name);
+//             memcpy(path,dp->d_name,BUF_MAX);
+//             printk("../%s", "usr");
+//             if(stat(path, &sb_d) == -1)
+//                /* exit("stat");*/
+
+//             //得到当前目录对应的条目并将目录逐渐完善
+//             if(dev == sb_d.st_dev && ino == sb_d.st_ino){
+//                 memset(cwd, 0, sizeof(cwd));
+//                 if(strcat(cwd, "/") == NULL)
+//                    /* exit("strcat");*/
+//                 if(strcat(cwd, dp->d_name) == NULL)
+//                    /* exit("strcat");*/
+//                 if(strcat(cwd, buf) == NULL)
+//                    /* exit("strcat");*/
+
+//                 if(strncpy(buf, cwd, BUF_MAX) == NULL)
+//                    /* exit("strncpy");*/
+//                 break;
+//             }
+            
+//         }
+
+//         if(dp == NULL && errno != 0)
+//             /*exit("readdir");*/
+
+//         closedir(dirp);
+//         chdir("..");      //改变当前目录
+//     }
+//     //printk("%s\n",buff);
+//     /*
+//     for(i=0;i<10;i++)
+//     put_fs_byte(*(buff+i), (buf+i));
+//     put_fs_byte('\0', (buf+i));
+//     */
+//     return buf;
+// }
\ No newline at end of file