I have written a function which accepts DIR * as argument and lists files inside that (with readdir function)
In addition, I just want to be able to stat files returned by readdir. It is not clear where DIR * is pointing to, so is there a way to get full path of directory from DIR * or is there any other way that I can stat files with?
You can use dirfd(), as many other answers, and then for each entry read with readdir() call function fstatat():
int fstatat(int dirfd, const char *pathname, struct stat *buf, int flags); I think this relatively obscure function does just what you need.
Alternatively you could call openat() passing in the fd of the directory and the pathname read from the directory. Then do a fstat() to get the file stats.
I don't think so, but you should be able to use dirfd() to get the file descriptor corresponding to the DIR *, and using that you can call fchdir() to change into that directory.
Then the names returned by readdir() become local to your current dir, and you can just stat() them directly.
UPDATE: Just to clarify, this is not the same thing as calling chroot(), it's just an ordinary change of the process' current directory.
fchdir() he calls getcwd(), would he get the real name of the directory?DIR * is pointing to!Based on @unwind answer, and since you are in linux:
dirfd() to get the file descriptor of the directorygetpid()/proc/<pid>/fd/<dirfd> using readlink(). It will refer to your directory by name!fchdir! But these answers mean that there is no straight way of doing it, right?file-name -> dir-entry -> inode <- open-file-description <- file-descriptor (well, maybe not too exact, but you get the idea...). The /proc readlink method is just a linux hack to get to this information, which may be accurate.