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