projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| b688fc87 WJ |
1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1989 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 | * notice, this list of conditions and the following disclaimer in the | |
| 12 | * documentation and/or other materials provided with the distribution. | |
| 13 | * 3. All advertising materials mentioning features or use of this software | |
| 14 | * must display the following acknowledgement: | |
| 15 | * This product includes software developed by the University of | |
| 16 | * California, Berkeley and its contributors. | |
| 17 | * 4. Neither the name of the University nor the names of its contributors | |
| 18 | * may be used to endorse or promote products derived from this software | |
| 19 | * without specific prior written permission. | |
| 20 | * | |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 31 | * SUCH DAMAGE. | |
| 32 | * | |
| 33 | * @(#)dir.h 7.10 (Berkeley) 3/25/91 | |
| 34 | */ | |
| 35 | ||
| 36 | #ifndef _DIR_H_ | |
| 37 | #define _DIR_H_ | |
| 38 | ||
| 39 | /* | |
| 40 | * A directory consists of some number of blocks of DIRBLKSIZ | |
| 41 | * bytes, where DIRBLKSIZ is chosen such that it can be transferred | |
| 42 | * to disk in a single atomic operation (e.g. 512 bytes on most machines). | |
| 43 | * | |
| 44 | * Each DIRBLKSIZ byte block contains some number of directory entry | |
| 45 | * structures, which are of variable length. Each directory entry has | |
| 46 | * a struct direct at the front of it, containing its inode number, | |
| 47 | * the length of the entry, and the length of the name contained in | |
| 48 | * the entry. These are followed by the name padded to a 4 byte boundary | |
| 49 | * with null bytes. All names are guaranteed null terminated. | |
| 50 | * The maximum length of a name in a directory is MAXNAMLEN. | |
| 51 | * | |
| 52 | * The macro DIRSIZ(dp) gives the amount of space required to represent | |
| 53 | * a directory entry. Free space in a directory is represented by | |
| 54 | * entries which have dp->d_reclen > DIRSIZ(dp). All DIRBLKSIZ bytes | |
| 55 | * in a directory block are claimed by the directory entries. This | |
| 56 | * usually results in the last entry in a directory having a large | |
| 57 | * dp->d_reclen. When entries are deleted from a directory, the | |
| 58 | * space is returned to the previous entry in the same directory | |
| 59 | * block by increasing its dp->d_reclen. If the first entry of | |
| 60 | * a directory block is free, then its dp->d_ino is set to 0. | |
| 61 | * Entries other than the first in a directory do not normally have | |
| 62 | * dp->d_ino set to 0. | |
| 63 | */ | |
| 64 | #define DIRBLKSIZ DEV_BSIZE | |
| 65 | #define MAXNAMLEN 255 | |
| 66 | ||
| 67 | struct direct { | |
| 68 | u_long d_ino; /* inode number of entry */ | |
| 69 | u_short d_reclen; /* length of this record */ | |
| 70 | u_short d_namlen; /* length of string in d_name */ | |
| 71 | char d_name[MAXNAMLEN + 1]; /* name with length <= MAXNAMLEN */ | |
| 72 | }; | |
| 73 | ||
| 74 | /* | |
| 75 | * The DIRSIZ macro gives the minimum record length which will hold | |
| 76 | * the directory entry. This requires the amount of space in struct direct | |
| 77 | * without the d_name field, plus enough space for the name with a terminating | |
| 78 | * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. | |
| 79 | */ | |
| 80 | #define DIRSIZ(dp) \ | |
| 81 | ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) | |
| 82 | ||
| 83 | /* | |
| 84 | * Template for manipulating directories. | |
| 85 | * Should use struct direct's, but the name field | |
| 86 | * is MAXNAMLEN - 1, and this just won't do. | |
| 87 | */ | |
| 88 | struct dirtemplate { | |
| 89 | u_long dot_ino; | |
| 90 | short dot_reclen; | |
| 91 | short dot_namlen; | |
| 92 | char dot_name[4]; /* must be multiple of 4 */ | |
| 93 | u_long dotdot_ino; | |
| 94 | short dotdot_reclen; | |
| 95 | short dotdot_namlen; | |
| 96 | char dotdot_name[4]; /* ditto */ | |
| 97 | }; | |
| 98 | #endif /* !_DIR_H_ */ |