usr/src/sys/ufs/ffs/dir.h

/*      dir.h   4.3     82/04/19        */

/* @(#)ndir.h 4.4 3/30/82 */

/*
 * This sets the "page size" for directories.
 * Requirements are DEV_BSIZE <= DIRBLKSIZ <= MINBSIZE with
 * DIRBLKSIZ a power of two.
 * Dennis Ritchie feels that directory pages should be atomic
 * operations to the disk, so we use DEV_BSIZE.
 */
#define DIRBLKSIZ DEV_BSIZE

/*
 * This limits the directory name length. Its main constraint
 * is that it appears twice in the user structure. (u. area)
 */
#define MAXNAMLEN 255

struct  direct {
        u_long  d_ino;
        short   d_reclen;
        short   d_namlen;
        char    d_name[MAXNAMLEN + 1];
        /* typically shorter */
};

struct _dirdesc {
        int     dd_fd;
        long    dd_loc;
        long    dd_size;
        char    dd_buf[DIRBLKSIZ];
};

/*
 * useful macros.
 */
#undef DIRSIZ
#define DIRSIZ(dp) \
    ((sizeof(struct direct) - MAXNAMLEN + (dp)->d_namlen + sizeof(ino_t) - 1) &\
    ~(sizeof(ino_t) - 1))
typedef struct _dirdesc DIR;
#ifndef NULL
#define NULL    0
#endif

/*
 * functions defined on directories
 */
extern DIR *opendir();
extern struct direct *readdir();
extern long telldir();
extern void seekdir();
#define rewinddir(dirp) seekdir((dirp), 0)
extern void closedir();