1 /* Extended tar format from POSIX.1. 2 Copyright (C) 1992, 1996 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Written by David J. MacKenzie. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef _TAR_H 21 #define _TAR_H 1 22 23 /* A tar archive consists of 512-byte blocks. 24 Each file in the archive has a header block followed by 0+ data blocks. 25 Two blocks of NUL bytes indicate the end of the archive. */ 26 27 /* The fields of header blocks: 28 All strings are stored as ISO 646 (approximately ASCII) strings. 29 30 Fields are numeric unless otherwise noted below; numbers are ISO 646 31 representations of octal numbers, with leading zeros as needed. 32 33 linkname is only valid when typeflag==LNKTYPE. It doesn't use prefix; 34 files that are links to pathnames >100 chars long can not be stored 35 in a tar archive. 36 37 If typeflag=={LNKTYPE,SYMTYPE,DIRTYPE} then size must be 0. 38 39 devmajor and devminor are only valid for typeflag=={BLKTYPE,CHRTYPE}. 40 41 chksum contains the sum of all 512 bytes in the header block, 42 treating each byte as an 8-bit unsigned value and treating the 43 8 bytes of chksum as blank characters. 44 45 uname and gname are used in preference to uid and gid, if those 46 names exist locally. 47 48 Field Name Byte Offset Length in Bytes Field Type 49 name 0 100 NUL-terminated if NUL fits 50 mode 100 8 51 uid 108 8 52 gid 116 8 53 size 124 12 54 mtime 136 12 55 chksum 148 8 56 typeflag 156 1 see below 57 linkname 157 100 NUL-terminated if NUL fits 58 magic 257 6 must be TMAGIC (NUL term.) 59 version 263 2 must be TVERSION 60 uname 265 32 NUL-terminated 61 gname 297 32 NUL-terminated 62 devmajor 329 8 63 devminor 337 8 64 prefix 345 155 NUL-terminated if NUL fits 65 66 If the first character of prefix is '\0', the file name is name; 67 otherwise, it is prefix/name. Files whose pathnames don't fit in that 68 length can not be stored in a tar archive. */ 69 70 /* The bits in mode: */ 71 #define TSUID 04000 72 #define TSGID 02000 73 #define TSVTX 01000 74 #define TUREAD 00400 75 #define TUWRITE 00200 76 #define TUEXEC 00100 77 #define TGREAD 00040 78 #define TGWRITE 00020 79 #define TGEXEC 00010 80 #define TOREAD 00004 81 #define TOWRITE 00002 82 #define TOEXEC 00001 83 84 /* The values for typeflag: 85 Values 'A'-'Z' are reserved for custom implementations. 86 All other values are reserved for future POSIX.1 revisions. */ 87 88 #define REGTYPE '0' /* Regular file (preferred code). */ 89 #define AREGTYPE '\0' /* Regular file (alternate code). */ 90 #define LNKTYPE '1' /* Hard link. */ 91 #define SYMTYPE '2' /* Symbolic link (hard if not supported). */ 92 #define CHRTYPE '3' /* Character special. */ 93 #define BLKTYPE '4' /* Block special. */ 94 #define DIRTYPE '5' /* Directory. */ 95 #define FIFOTYPE '6' /* Named pipe. */ 96 #define CONTTYPE '7' /* Contiguous file */ 97 /* (regular file if not supported). */ 98 99 /* Contents of magic field and its length. */ 100 #define TMAGIC "ustar" 101 #define TMAGLEN 6 102 103 /* Contents of the version field and its length. */ 104 #define TVERSION "00" 105 #define TVERSLEN 2 106 107 #endif /* tar.h */ 108