/* Extended tar format from POSIX.1.
Copyright (C) 1992-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written by David J. MacKenzie.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* A tar archive consists of 512-byte blocks.
Each file in the archive has a header block followed by 0+ data blocks.
Two blocks of NUL bytes indicate the end of the archive. */
/* The fields of header blocks:
All strings are stored as ISO 646 (approximately ASCII) strings.
Fields are numeric unless otherwise noted below; numbers are ISO 646
representations of octal numbers, with leading zeros as needed.
linkname is only valid when typeflag==LNKTYPE. It doesn't use prefix;
files that are links to pathnames >100 chars long can not be stored
If typeflag=={LNKTYPE,SYMTYPE,DIRTYPE} then size must be 0.
devmajor and devminor are only valid for typeflag=={BLKTYPE,CHRTYPE}.
chksum contains the sum of all 512 bytes in the header block,
treating each byte as an 8-bit unsigned value and treating the
8 bytes of chksum as blank characters.
uname and gname are used in preference to uid and gid, if those
Field Name Byte Offset Length in Bytes Field Type
name 0 100 NUL-terminated if NUL fits
linkname 157 100 NUL-terminated if NUL fits
magic 257 6 must be TMAGIC (NUL term.)
version 263 2 must be TVERSION
uname 265 32 NUL-terminated
gname 297 32 NUL-terminated
prefix 345 155 NUL-terminated if NUL fits
If the first character of prefix is '\0', the file name is name;
otherwise, it is prefix/name. Files whose pathnames don't fit in that
length can not be stored in a tar archive. */
#if defined __USE_XOPEN || !defined __USE_XOPEN2K
/* The values for typeflag:
Values 'A'-'Z' are reserved for custom implementations.
All other values are reserved for future POSIX.1 revisions. */
#define REGTYPE '0' /* Regular file (preferred code). */
#define AREGTYPE '\0' /* Regular file (alternate code). */
#define LNKTYPE '1' /* Hard link. */
#define SYMTYPE '2' /* Symbolic link (hard if not supported). */
#define CHRTYPE '3' /* Character special. */
#define BLKTYPE '4' /* Block special. */
#define DIRTYPE '5' /* Directory. */
#define FIFOTYPE '6' /* Named pipe. */
#define CONTTYPE '7' /* Contiguous file */
/* (regular file if not supported). */
/* Contents of magic field and its length. */
/* Contents of the version field and its length. */