88 lines
2.8 KiB
C
Executable file
88 lines
2.8 KiB
C
Executable file
/* dirent.h - Declarations for directory reading routines.
|
|
* Author: Kees J. Bot
|
|
* 24 Apr 1989
|
|
*
|
|
* Note: The V7 format directory entries used under Minix must be transformed
|
|
* into a struct dirent with a d_name of at least 15 characters. Given that
|
|
* we have to transform V7 entries anyhow it is little trouble to let the
|
|
* routines understand the so-called "flex" directory format too.
|
|
*/
|
|
|
|
#ifndef _DIRENT_H
|
|
#define _DIRENT_H
|
|
|
|
#ifndef _TYPES_H
|
|
#include <sys/types.h>
|
|
#endif
|
|
|
|
#include <sys/dir.h>
|
|
|
|
/* _fl_direct is a flexible directory entry. Actually it's a union of 8
|
|
* characters and the 3 fields defined below.
|
|
*/
|
|
|
|
/* Flexible directory entry: */
|
|
struct _fl_direct { /* First slot in an entry */
|
|
ino_t d_ino;
|
|
unsigned char d_extent;
|
|
char d_name[3]; /* two characters for the shortest name */
|
|
};
|
|
|
|
/* Name of length len needs _EXTENT(len) extra slots. */
|
|
#define _EXTENT(len) (((len) + 5) >> 3)
|
|
|
|
/* Version 7 directory entry: */
|
|
struct _v7_direct {
|
|
ino_t d_ino;
|
|
char d_name[DIRSIZ];
|
|
};
|
|
|
|
/* The block size must be at least 1024 bytes, because otherwise
|
|
* the superblock (at 1024 bytes) overlaps with other filesystem data.
|
|
*/
|
|
#define MIN_BLOCK_SIZE 1024
|
|
|
|
/* The below is allocated in some parts of the system as the largest
|
|
* a filesystem block can be. For instance, the boot monitor allocates
|
|
* 3 of these blocks and has to fit within 64kB, so this can't be
|
|
* increased without taking that into account.
|
|
*/
|
|
#define MAX_BLOCK_SIZE 8192
|
|
|
|
/* This is the block size for the fixed versions of the filesystem (V1/V2) */
|
|
#define STATIC_BLOCK_SIZE 1024
|
|
|
|
#define STATIC_FLEX_PER_BLOCK (STATIC_BLOCK_SIZE/sizeof(struct _fl_direct))
|
|
#define FLEX_PER_V7 (_EXTENT(DIRSIZ) + 1)
|
|
#define FLEX_PER_BLOCK (STATIC_BLOCK_SIZE/sizeof(struct _fl_direct))
|
|
|
|
/* Definitions for the directory(3) routines: */
|
|
typedef struct {
|
|
char _fd; /* Filedescriptor of open directory */
|
|
char _v7; /* Directory is Version 7 */
|
|
short _count; /* This many objects in buf */
|
|
off_t _pos; /* Position in directory file */
|
|
struct _fl_direct *_ptr; /* Next slot in buf */
|
|
struct _fl_direct _buf[FLEX_PER_BLOCK]; /* One block of a directory file */
|
|
struct _fl_direct _v7f[FLEX_PER_V7]; /* V7 entry transformed to flex */
|
|
} DIR;
|
|
|
|
struct dirent { /* Largest entry (8 slots) */
|
|
ino_t d_ino; /* I-node number */
|
|
unsigned char d_extent; /* Extended with this many slots */
|
|
char d_name[61]; /* Null terminated name */
|
|
};
|
|
|
|
/* Function Prototypes. */
|
|
_PROTOTYPE( int closedir, (DIR *_dirp) );
|
|
_PROTOTYPE( DIR *opendir, (const char *_dirname) );
|
|
_PROTOTYPE( struct dirent *readdir, (DIR *_dirp) );
|
|
_PROTOTYPE( void rewinddir, (DIR *_dirp) );
|
|
|
|
#ifdef _MINIX
|
|
_PROTOTYPE( int seekdir, (DIR *_dirp, off_t _loc) );
|
|
_PROTOTYPE( off_t telldir, (DIR *_dirp) );
|
|
#endif
|
|
|
|
#endif /* _DIRENT_H */
|