contrib/cpio/tar.h

   1 /* Extended tar format from POSIX.1.
   2    Copyright (C) 1992 Free Software Foundation, Inc.
   3    Written by David J. MacKenzie.
   4
   5 This file is part of the GNU C Library.
   6
   7 The GNU C Library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public License as
   9 published by the Free Software Foundation; either version 2 of the
  10 License, or (at your option) any later version.
  11
  12 The GNU C Library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with the GNU C Library; see the file COPYING.LIB.  If
  19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20 Cambridge, MA 02139, USA.  */
  21
  22 #ifndef _TAR_H
  23
  24 #define _TAR_H  1
  25
  26
  27 /* A tar archive consists of 512-byte blocks.
  28    Each file in the archive has a header block followed by 0+ data blocks.
  29    Two blocks of NUL bytes indicate the end of the archive.  */
  30
  31 /* The fields of header blocks:
  32    All strings are stored as ISO 646 (approximately ASCII) strings.
  33
  34    Fields are numeric unless otherwise noted below; numbers are ISO 646
  35    representations of octal numbers, with leading zeros as needed.
  36
  37    linkname is only valid when typeflag==LNKTYPE.  It doesn't use prefix;
  38    files that are links to pathnames >100 chars long can not be stored
  39    in a tar archive.
  40
  41    If typeflag=={LNKTYPE,SYMTYPE,DIRTYPE} then size must be 0.
  42
  43    devmajor and devminor are only valid for typeflag=={BLKTYPE,CHRTYPE}.
  44
  45    chksum contains the sum of all 512 bytes in the header block,
  46    treating each byte as an 8-bit unsigned value and treating the
  47    8 bytes of chksum as blank characters.
  48
  49    uname and gname are used in preference to uid and gid, if those
  50    names exist locally.
  51
  52    Field Name   Byte Offset     Length in Bytes Field Type
  53    name         0               100             NUL-terminated if NUL fits
  54    mode         100             8
  55    uid          108             8
  56    gid          116             8
  57    size         124             12
  58    mtime        136             12
  59    chksum       148             8
  60    typeflag     156             1               see below
  61    linkname     157             100             NUL-terminated if NUL fits
  62    magic        257             6               must be TMAGIC (NUL term.)
  63    version      263             2               must be TVERSION
  64    uname        265             32              NUL-terminated
  65    gname        297             32              NUL-terminated
  66    devmajor     329             8
  67    devminor     337             8
  68    prefix       345             155             NUL-terminated if NUL fits
  69
  70    If the first character of prefix is '\0', the file name is name;
  71    otherwise, it is prefix/name.  Files whose pathnames don't fit in that
  72    length can not be stored in a tar archive.  */
  73
  74 /* The bits in mode: */
  75 #define TSUID   04000
  76 #define TSGID   02000
  77 #define TSVTX   01000
  78 #define TUREAD  00400
  79 #define TUWRITE 00200
  80 #define TUEXEC  00100
  81 #define TGREAD  00040
  82 #define TGWRITE 00020
  83 #define TGEXEC  00010
  84 #define TOREAD  00004
  85 #define TOWRITE 00002
  86 #define TOEXEC  00001
  87
  88 /* The values for typeflag:
  89    Values 'A'-'Z' are reserved for custom implementations.
  90    All other values are reserved for future POSIX.1 revisions.  */
  91
  92 #define REGTYPE         '0'     /* Regular file (preferred code).  */
  93 #define AREGTYPE        '\0'    /* Regular file (alternate code).  */
  94 #define LNKTYPE         '1'     /* Hard link.  */
  95 #define SYMTYPE         '2'     /* Symbolic link (hard if not supported).  */
  96 #define CHRTYPE         '3'     /* Character special.  */
  97 #define BLKTYPE         '4'     /* Block special.  */
  98 #define DIRTYPE         '5'     /* Directory.  */
  99 #define FIFOTYPE        '6'     /* Named pipe.  */
 100 #define CONTTYPE        '7'     /* Contiguous file */
 101                                 /* (regular file if not supported).  */
 102
 103 /* Contents of magic field and its length.  */
 104 #define TMAGIC  "ustar"
 105 #define TMAGLEN 6
 106
 107 /* Contents of the version field and its length.  */
 108 #define TVERSION "00"
 109 #define TVERSLEN 2
 110
 111
 112 #endif  /* tar.h */