Reading Directories

• Just like files, open, read, close
• Man 2 readdir :)
• Everything is based of a dirent struct

•            struct dirent {
                 ino_t          d_ino;       /* inode number */
                 off_t          d_off;       /* not an offset; see NOTES */
                 unsigned short d_reclen;    /* length of this record */
                 unsigned char  d_type;      /* type of file; not supported
                                                by all filesystem types */
                 char           d_name[256]; /* filename */
             };
      

• open

  •        #include <sys/types.h>
           #include <dirent.h>
    
           DIR *opendir(const char *name);
    
    	

  • Returns a DIR * or NULL
• read

  •        #include <dirent.h>
           struct dirent *readdir(DIR *dirp);
    	

  • dirent as above.
  • Returns NULL when you reach the end.
  • The man page says only d_name and d_ino are standard.
  • We will look at how to get more information on a file in the next set of notes.
• close

  •        #include <sys/types.h>
           #include <dirent.h>
           int closedir(DIR *dirp);