dir(5) — sys5



DIR(5)          DOMAIN/IX Reference Manual (SYS5)          DIR(5)



NAME
     dir - format of directories

USAGE
     #include <sys/dir.h>

DESCRIPTION
     A directory behaves exactly like an ordinary file, save that
     no user may write into a directory.  The fact that a file is
     a directory is indicated by a bit in the flag word of its
     inode entry.  The structure of a directory entry as given in
     the include file is:

          #ifndef DEV_BSIZE
          #define DEV_BSIZE   1024
          #endif
          #define DIRBLKSIZ   DEV_BSIZE
          #define MAXNAMLEN   32

          struct  direct {
                  unsigned longd_ino;
                  short d_reclen;
                  short d_namlen;
                  char  d_name[MAXNAMLEN + 1];
          };

          /*
           * The DIRSIZ macro gives the minimum record length which will hold
           * the directory entry.  This requires the amount of space in struct direct
           * without the d_name field, plus enough space for the name with a terminating
           * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
           */
          #undef DIRSIZ
          #define DIRSIZ(dp)     ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

          /*
           * Definitions for library routines operating on directories.
           */
          typedef struct _dirdesc {
                  int   dd_fd;
                  long  dd_loc;
                  long  dd_size;
                  char  dd_buf[DIRBLKSIZ];
          } DIR;
          #ifndef NULL
          #define NULL 0
          #endif
          extern  DIR *opendir();
          extern  struct direct *readdir();
          extern  long telldir();
          extern  void seekdir();
          #define rewinddir(dirp)seekdir((dirp), (long)0)



Printed 5/10/85                                             DIR-1



DIR(5)          DOMAIN/IX Reference Manual (SYS5)          DIR(5)



          extern  void closedir();

     By convention, the first two entries in each directory are
     for . and ...  The first is an entry for the directory
     itself.  The second is for the parent directory.  The mean-
     ing of .. is modified for the root directory of the master
     file system; there is no parent, so .. has the same meaning
     as ..















































DIR-2                                             Printed 5/10/85

Museum