| 1 | /* dirent.h - Declarations for directory reading routines.
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| 2 | * Author: Kees J. Bot
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| 3 | * 24 Apr 1989
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| 4 | *
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| 5 | * Note: The V7 format directory entries used under Minix must be transformed
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| 6 | * into a struct dirent with a d_name of at least 15 characters. Given that
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| 7 | * we have to transform V7 entries anyhow it is little trouble to let the
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| 8 | * routines understand the so-called "flex" directory format too.
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| 9 | */
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| 10 |
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| 11 | #ifndef _DIRENT_H
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| 12 | #define _DIRENT_H
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| 13 |
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| 14 | #ifndef _TYPES_H
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| 15 | #include <sys/types.h>
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| 16 | #endif
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| 17 |
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| 18 | #include <sys/dir.h>
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| 19 |
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| 20 | /* _fl_direct is a flexible directory entry. Actually it's a union of 8
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| 21 | * characters and the 3 fields defined below.
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| 22 | */
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| 23 |
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| 24 | /* Flexible directory entry: */
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| 25 | struct _fl_direct { /* First slot in an entry */
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| 26 | ino_t d_ino;
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| 27 | unsigned char d_extent;
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| 28 | char d_name[3]; /* two characters for the shortest name */
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| 29 | };
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| 30 |
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| 31 | /* Name of length len needs _EXTENT(len) extra slots. */
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| 32 | #define _EXTENT(len) (((len) + 5) >> 3)
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| 33 |
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| 34 | /* Version 7 directory entry: */
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| 35 | struct _v7_direct {
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| 36 | ino_t d_ino;
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| 37 | char d_name[DIRSIZ];
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| 38 | };
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| 39 |
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| 40 | /* The block size must be at least 1024 bytes, because otherwise
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| 41 | * the superblock (at 1024 bytes) overlaps with other filesystem data.
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| 42 | */
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| 43 | #define MIN_BLOCK_SIZE 1024
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| 44 |
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| 45 | /* The below is allocated in some parts of the system as the largest
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| 46 | * a filesystem block can be. For instance, the boot monitor allocates
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| 47 | * 3 of these blocks and has to fit within 64kB, so this can't be
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| 48 | * increased without taking that into account.
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| 49 | */
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| 50 | #define MAX_BLOCK_SIZE 4096
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| 51 |
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| 52 | /* This is the block size for the fixed versions of the filesystem (V1/V2) */
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| 53 | #define STATIC_BLOCK_SIZE 1024
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| 54 |
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| 55 | #define STATIC_FLEX_PER_BLOCK (STATIC_BLOCK_SIZE/sizeof(struct _fl_direct))
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| 56 | #define FLEX_PER_V7 (_EXTENT(DIRSIZ) + 1)
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| 57 | #define FLEX_PER_BLOCK (STATIC_BLOCK_SIZE/sizeof(struct _fl_direct))
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| 58 |
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| 59 | /* Definitions for the directory(3) routines: */
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| 60 | typedef struct {
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| 61 | char _fd; /* Filedescriptor of open directory */
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| 62 | char _v7; /* Directory is Version 7 */
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| 63 | short _count; /* This many objects in buf */
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| 64 | off_t _pos; /* Position in directory file */
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| 65 | struct _fl_direct *_ptr; /* Next slot in buf */
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| 66 | struct _fl_direct _buf[FLEX_PER_BLOCK]; /* One block of a directory file */
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| 67 | struct _fl_direct _v7f[FLEX_PER_V7]; /* V7 entry transformed to flex */
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| 68 | } DIR;
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| 69 |
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| 70 | #define _DIRENT_NAME_LEN 61
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| 71 |
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| 72 | struct dirent { /* Largest entry (8 slots) */
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| 73 | ino_t d_ino; /* I-node number */
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| 74 | unsigned char d_extent; /* Extended with this many slots */
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| 75 | char d_name[_DIRENT_NAME_LEN]; /* Null terminated name */
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| 76 | };
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| 77 |
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| 78 | /* Function Prototypes. */
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| 79 | _PROTOTYPE( int closedir, (DIR *_dirp) );
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| 80 | _PROTOTYPE( DIR *opendir, (const char *_dirname) );
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| 81 | _PROTOTYPE( struct dirent *readdir, (DIR *_dirp) );
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| 82 | _PROTOTYPE( void rewinddir, (DIR *_dirp) );
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| 83 |
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| 84 | #ifdef _MINIX
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| 85 | _PROTOTYPE( int seekdir, (DIR *_dirp, off_t _loc) );
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| 86 | _PROTOTYPE( off_t telldir, (DIR *_dirp) );
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| 87 | #endif
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| 88 |
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| 89 | #endif /* _DIRENT_H */
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