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da7c5cc6 | 1 | /* |
c53fd45c KM |
2 | * Copyright (c) 1982, 1986, 1989 The Regents of the University of California. |
3 | * All rights reserved. | |
da7c5cc6 | 4 | * |
c53fd45c KM |
5 | * Redistribution and use in source and binary forms are permitted |
6 | * provided that the above copyright notice and this paragraph are | |
7 | * duplicated in all such forms and that any documentation, | |
8 | * advertising materials, and other materials related to such | |
9 | * distribution and use acknowledge that the software was developed | |
10 | * by the University of California, Berkeley. The name of the | |
11 | * University may not be used to endorse or promote products derived | |
12 | * from this software without specific prior written permission. | |
13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
16 | * | |
e40b7cb3 | 17 | * @(#)dir.h 7.5 (Berkeley) %G% |
da7c5cc6 | 18 | */ |
ad30fb67 KM |
19 | |
20 | /* | |
58765c2f BJ |
21 | * A directory consists of some number of blocks of DIRBLKSIZ |
22 | * bytes, where DIRBLKSIZ is chosen such that it can be transferred | |
23 | * to disk in a single atomic operation (e.g. 512 bytes on most machines). | |
24 | * | |
25 | * Each DIRBLKSIZ byte block contains some number of directory entry | |
26 | * structures, which are of variable length. Each directory entry has | |
27 | * a struct direct at the front of it, containing its inode number, | |
28 | * the length of the entry, and the length of the name contained in | |
29 | * the entry. These are followed by the name padded to a 4 byte boundary | |
30 | * with null bytes. All names are guaranteed null terminated. | |
31 | * The maximum length of a name in a directory is MAXNAMLEN. | |
32 | * | |
33 | * The macro DIRSIZ(dp) gives the amount of space required to represent | |
34 | * a directory entry. Free space in a directory is represented by | |
35 | * entries which have dp->d_reclen > DIRSIZ(dp). All DIRBLKSIZ bytes | |
36 | * in a directory block are claimed by the directory entries. This | |
37 | * usually results in the last entry in a directory having a large | |
38 | * dp->d_reclen. When entries are deleted from a directory, the | |
39 | * space is returned to the previous entry in the same directory | |
40 | * block by increasing its dp->d_reclen. If the first entry of | |
41 | * a directory block is free, then its dp->d_ino is set to 0. | |
42 | * Entries other than the first in a directory do not normally have | |
43 | * dp->d_ino set to 0. | |
ad30fb67 | 44 | */ |
e40b7cb3 MT |
45 | #define DIRBLKSIZ DEV_BSIZE |
46 | #define MAXNAMLEN 255 | |
ad30fb67 KM |
47 | |
48 | struct direct { | |
58765c2f BJ |
49 | u_long d_ino; /* inode number of entry */ |
50 | u_short d_reclen; /* length of this record */ | |
51 | u_short d_namlen; /* length of string in d_name */ | |
52 | char d_name[MAXNAMLEN + 1]; /* name must be no longer than this */ | |
ad30fb67 KM |
53 | }; |
54 | ||
55 | /* | |
58765c2f BJ |
56 | * The DIRSIZ macro gives the minimum record length which will hold |
57 | * the directory entry. This requires the amount of space in struct direct | |
58 | * without the d_name field, plus enough space for the name with a terminating | |
59 | * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. | |
ad30fb67 KM |
60 | */ |
61 | #undef DIRSIZ | |
62 | #define DIRSIZ(dp) \ | |
58765c2f | 63 | ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) |
ad30fb67 | 64 | |
c53fd45c KM |
65 | #ifdef KERNEL |
66 | /* | |
67 | * Template for manipulating directories. | |
68 | * Should use struct direct's, but the name field | |
69 | * is MAXNAMLEN - 1, and this just won't do. | |
70 | */ | |
71 | struct dirtemplate { | |
72 | u_long dot_ino; | |
73 | short dot_reclen; | |
74 | short dot_namlen; | |
75 | char dot_name[4]; /* must be multiple of 4 */ | |
76 | u_long dotdot_ino; | |
77 | short dotdot_reclen; | |
78 | short dotdot_namlen; | |
79 | char dotdot_name[4]; /* ditto */ | |
80 | }; | |
81 | #endif | |
82 | ||
83 | /* | |
84 | * The following information should be obtained from <dirent.h> | |
85 | * and is provided solely (and temporarily) for backward compatibility. | |
86 | */ | |
58765c2f | 87 | #ifndef KERNEL |
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88 | #ifndef DEV_BSIZE |
89 | #define DEV_BSIZE 512 | |
90 | #endif | |
ad30fb67 | 91 | /* |
58765c2f | 92 | * Definitions for library routines operating on directories. |
ad30fb67 | 93 | */ |
58765c2f BJ |
94 | typedef struct _dirdesc { |
95 | int dd_fd; | |
96 | long dd_loc; | |
97 | long dd_size; | |
98 | char dd_buf[DIRBLKSIZ]; | |
99 | } DIR; | |
7436c231 KB |
100 | |
101 | #define dirfd(dirp) ((dirp)->dd_fd) | |
102 | ||
af0b24db SL |
103 | #ifndef NULL |
104 | #define NULL 0 | |
105 | #endif | |
58765c2f BJ |
106 | extern DIR *opendir(); |
107 | extern struct direct *readdir(); | |
108 | extern long telldir(); | |
109 | extern void seekdir(); | |
110 | #define rewinddir(dirp) seekdir((dirp), (long)0) | |
111 | extern void closedir(); | |
c53fd45c | 112 | #endif /* not KERNEL */ |