Write your own shell command pwd

Idea: (1) get "." The I node number, which is called N (using stat)

(2) ChDir. (using ChDir)

(3) Find the node with inode number n and get its file name.

Repeat the operation until the current directory "." The inode value equals "..." The Inode value

#include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <dirent.h>ino_t get_ Inode (char *), void Printpathto (ino_t), void Inum_to_name (ino_t, char *,int), int main () {Printpathto (Get_inode (".")); printf ("\ n"); return 0;} ino_t Get_inode (char * filename) {struct stat buffer;if (lstat (filename,&buffer) = =-1) {perror ("can ' t stat"); exit (1) ;} return Buffer.st_ino;} void Printpathto (ino_t ino) {ino_t ino_parent = Get_inode (".."); if (ino_parent = = Ino) return;else{struct stat S;char buffer[255];chdir (".."); Inum_to_name (ino,buffer,255);p Rintpathto (ino_parent);p rintf ("/%s", buffer);}}  void Inum_to_name (ino_t Ino,char * buffer,int buffer_length) {DIR * dir;struct dirent * direntp;struct stat Stat_buffer;dir = Opendir ("."); if (dir = = NULL) {perror ("can ' t open dir."); Exit (1);} while (direntp = Readdir (dir)) = NULL) {lstat (Direntp->d_name,&stat_buffer); if (Stat_buffer.st_ino = = Ino) { strncpy (buffer,direntp->d_name,buffer_length); buffer[buffer_length-1] = ' + '; Closedir (dir); return;}} 

Write your own shell command pwd