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author | Kim Kibum <kb0929.kim@samsung.com> | 2012-05-21 17:49:43 +0900 |
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committer | Kim Kibum <kb0929.kim@samsung.com> | 2012-05-21 17:49:43 +0900 |
commit | b253dd7cd3994d94137556defe22e56e94a19805 (patch) | |
tree | cd0adaff3fbd9102284027f894b48606fc581dd1 /doc/header.texi | |
parent | bfd95772edacf96422314ea6b6ad1f17054e4a85 (diff) | |
download | tar-b253dd7cd3994d94137556defe22e56e94a19805.tar.gz tar-b253dd7cd3994d94137556defe22e56e94a19805.tar.bz2 tar-b253dd7cd3994d94137556defe22e56e94a19805.zip |
Upload Tizen:Base source
Diffstat (limited to 'doc/header.texi')
-rw-r--r-- | doc/header.texi | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/doc/header.texi b/doc/header.texi new file mode 100644 index 0000000..0d1616e --- /dev/null +++ b/doc/header.texi @@ -0,0 +1,242 @@ +@comment GNU tar Archive Format description. +@comment +@comment Copyright (C) 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, +@comment 2000, 2001, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. +@comment +@comment This program is free software; you can redistribute it and/or modify it +@comment under the terms of the GNU General Public License as published by the +@comment Free Software Foundation; either version 2, or (at your option) any later +@comment version. +@comment +@comment This program is distributed in the hope that it will be useful, but +@comment WITHOUT ANY WARRANTY; without even the implied warranty of +@comment MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General +@comment Public License for more details. +@comment +@comment You should have received a copy of the GNU General Public License along +@comment with this program; if not, write to the Free Software Foundation, Inc., +@comment 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + +/*@r{ tar Header Block, from POSIX 1003.1-1990. }*/ + +/*@r{ POSIX header. }*/ + +struct posix_header +@{ /*@r{ byte offset }*/ + char name[100]; /*@r{ 0 }*/ + char mode[8]; /*@r{ 100 }*/ + char uid[8]; /*@r{ 108 }*/ + char gid[8]; /*@r{ 116 }*/ + char size[12]; /*@r{ 124 }*/ + char mtime[12]; /*@r{ 136 }*/ + char chksum[8]; /*@r{ 148 }*/ + char typeflag; /*@r{ 156 }*/ + char linkname[100]; /*@r{ 157 }*/ + char magic[6]; /*@r{ 257 }*/ + char version[2]; /*@r{ 263 }*/ + char uname[32]; /*@r{ 265 }*/ + char gname[32]; /*@r{ 297 }*/ + char devmajor[8]; /*@r{ 329 }*/ + char devminor[8]; /*@r{ 337 }*/ + char prefix[155]; /*@r{ 345 }*/ + /*@r{ 500 }*/ +@}; + +#define TMAGIC "ustar" /*@r{ ustar and a null }*/ +#define TMAGLEN 6 +#define TVERSION "00" /*@r{ 00 and no null }*/ +#define TVERSLEN 2 + +/*@r{ Values used in typeflag field. }*/ +#define REGTYPE '0' /*@r{ regular file }*/ +#define AREGTYPE '\0' /*@r{ regular file }*/ +#define LNKTYPE '1' /*@r{ link }*/ +#define SYMTYPE '2' /*@r{ reserved }*/ +#define CHRTYPE '3' /*@r{ character special }*/ +#define BLKTYPE '4' /*@r{ block special }*/ +#define DIRTYPE '5' /*@r{ directory }*/ +#define FIFOTYPE '6' /*@r{ FIFO special }*/ +#define CONTTYPE '7' /*@r{ reserved }*/ + +#define XHDTYPE 'x' /*@r{ Extended header referring to the + next file in the archive }*/ +#define XGLTYPE 'g' /*@r{ Global extended header }*/ + +/*@r{ Bits used in the mode field, values in octal. }*/ +#define TSUID 04000 /*@r{ set UID on execution }*/ +#define TSGID 02000 /*@r{ set GID on execution }*/ +#define TSVTX 01000 /*@r{ reserved }*/ + /*@r{ file permissions }*/ +#define TUREAD 00400 /*@r{ read by owner }*/ +#define TUWRITE 00200 /*@r{ write by owner }*/ +#define TUEXEC 00100 /*@r{ execute/search by owner }*/ +#define TGREAD 00040 /*@r{ read by group }*/ +#define TGWRITE 00020 /*@r{ write by group }*/ +#define TGEXEC 00010 /*@r{ execute/search by group }*/ +#define TOREAD 00004 /*@r{ read by other }*/ +#define TOWRITE 00002 /*@r{ write by other }*/ +#define TOEXEC 00001 /*@r{ execute/search by other }*/ + +/*@r{ tar Header Block, GNU extensions. }*/ + +/*@r{ In GNU tar, SYMTYPE is for to symbolic links, and CONTTYPE is for + contiguous files, so maybe disobeying the `reserved' comment in POSIX + header description. I suspect these were meant to be used this way, and + should not have really been `reserved' in the published standards. }*/ + +/*@r{ *BEWARE* *BEWARE* *BEWARE* that the following information is still + boiling, and may change. Even if the OLDGNU format description should be + accurate, the so-called GNU format is not yet fully decided. It is + surely meant to use only extensions allowed by POSIX, but the sketch + below repeats some ugliness from the OLDGNU format, which should rather + go away. Sparse files should be saved in such a way that they do *not* + require two passes at archive creation time. Huge files get some POSIX + fields to overflow, alternate solutions have to be sought for this. }*/ + +/*@r{ Descriptor for a single file hole. }*/ + +struct sparse +@{ /*@r{ byte offset }*/ + char offset[12]; /*@r{ 0 }*/ + char numbytes[12]; /*@r{ 12 }*/ + /*@r{ 24 }*/ +@}; + +/*@r{ Sparse files are not supported in POSIX ustar format. For sparse files + with a POSIX header, a GNU extra header is provided which holds overall + sparse information and a few sparse descriptors. When an old GNU header + replaces both the POSIX header and the GNU extra header, it holds some + sparse descriptors too. Whether POSIX or not, if more sparse descriptors + are still needed, they are put into as many successive sparse headers as + necessary. The following constants tell how many sparse descriptors fit + in each kind of header able to hold them. }*/ + +#define SPARSES_IN_EXTRA_HEADER 16 +#define SPARSES_IN_OLDGNU_HEADER 4 +#define SPARSES_IN_SPARSE_HEADER 21 + +/*@r{ Extension header for sparse files, used immediately after the GNU extra + header, and used only if all sparse information cannot fit into that + extra header. There might even be many such extension headers, one after + the other, until all sparse information has been recorded. }*/ + +struct sparse_header +@{ /*@r{ byte offset }*/ + struct sparse sp[SPARSES_IN_SPARSE_HEADER]; + /*@r{ 0 }*/ + char isextended; /*@r{ 504 }*/ + /*@r{ 505 }*/ +@}; + +/*@r{ The old GNU format header conflicts with POSIX format in such a way that + POSIX archives may fool old GNU tar's, and POSIX tar's might well be + fooled by old GNU tar archives. An old GNU format header uses the space + used by the prefix field in a POSIX header, and cumulates information + normally found in a GNU extra header. With an old GNU tar header, we + never see any POSIX header nor GNU extra header. Supplementary sparse + headers are allowed, however. }*/ + +struct oldgnu_header +@{ /*@r{ byte offset }*/ + char unused_pad1[345]; /*@r{ 0 }*/ + char atime[12]; /*@r{ 345 Incr. archive: atime of the file }*/ + char ctime[12]; /*@r{ 357 Incr. archive: ctime of the file }*/ + char offset[12]; /*@r{ 369 Multivolume archive: the offset of + the start of this volume }*/ + char longnames[4]; /*@r{ 381 Not used }*/ + char unused_pad2; /*@r{ 385 }*/ + struct sparse sp[SPARSES_IN_OLDGNU_HEADER]; + /*@r{ 386 }*/ + char isextended; /*@r{ 482 Sparse file: Extension sparse header + follows }*/ + char realsize[12]; /*@r{ 483 Sparse file: Real size}*/ + /*@r{ 495 }*/ +@}; + +/*@r{ OLDGNU_MAGIC uses both magic and version fields, which are contiguous. + Found in an archive, it indicates an old GNU header format, which will be + hopefully become obsolescent. With OLDGNU_MAGIC, uname and gname are + valid, though the header is not truly POSIX conforming. }*/ +#define OLDGNU_MAGIC "ustar " /*@r{ 7 chars and a null }*/ + +/*@r{ The standards committee allows only capital A through capital Z for + user-defined expansion. Other letters in use include: + + 'A' Solaris Access Control List + 'E' Solaris Extended Attribute File + 'I' Inode only, as in 'star' + 'N' Obsolete GNU tar, for file names that do not fit into the main header. + 'X' POSIX 1003.1-2001 eXtended (VU version) }*/ + +/*@r{ This is a dir entry that contains the names of files that were in the + dir at the time the dump was made. }*/ +#define GNUTYPE_DUMPDIR 'D' + +/*@r{ Identifies the *next* file on the tape as having a long linkname. }*/ +#define GNUTYPE_LONGLINK 'K' + +/*@r{ Identifies the *next* file on the tape as having a long name. }*/ +#define GNUTYPE_LONGNAME 'L' + +/*@r{ This is the continuation of a file that began on another volume. }*/ +#define GNUTYPE_MULTIVOL 'M' + +/*@r{ This is for sparse files. }*/ +#define GNUTYPE_SPARSE 'S' + +/*@r{ This file is a tape/volume header. Ignore it on extraction. }*/ +#define GNUTYPE_VOLHDR 'V' + +/*@r{ Solaris extended header }*/ +#define SOLARIS_XHDTYPE 'X' + +/*@r{ J@"org Schilling star header }*/ + +struct star_header +@{ /*@r{ byte offset }*/ + char name[100]; /*@r{ 0 }*/ + char mode[8]; /*@r{ 100 }*/ + char uid[8]; /*@r{ 108 }*/ + char gid[8]; /*@r{ 116 }*/ + char size[12]; /*@r{ 124 }*/ + char mtime[12]; /*@r{ 136 }*/ + char chksum[8]; /*@r{ 148 }*/ + char typeflag; /*@r{ 156 }*/ + char linkname[100]; /*@r{ 157 }*/ + char magic[6]; /*@r{ 257 }*/ + char version[2]; /*@r{ 263 }*/ + char uname[32]; /*@r{ 265 }*/ + char gname[32]; /*@r{ 297 }*/ + char devmajor[8]; /*@r{ 329 }*/ + char devminor[8]; /*@r{ 337 }*/ + char prefix[131]; /*@r{ 345 }*/ + char atime[12]; /*@r{ 476 }*/ + char ctime[12]; /*@r{ 488 }*/ + /*@r{ 500 }*/ +@}; + +#define SPARSES_IN_STAR_HEADER 4 +#define SPARSES_IN_STAR_EXT_HEADER 21 + +struct star_in_header +@{ + char fill[345]; /*@r{ 0 Everything that is before t_prefix }*/ + char prefix[1]; /*@r{ 345 t_name prefix }*/ + char fill2; /*@r{ 346 }*/ + char fill3[8]; /*@r{ 347 }*/ + char isextended; /*@r{ 355 }*/ + struct sparse sp[SPARSES_IN_STAR_HEADER]; /*@r{ 356 }*/ + char realsize[12]; /*@r{ 452 Actual size of the file }*/ + char offset[12]; /*@r{ 464 Offset of multivolume contents }*/ + char atime[12]; /*@r{ 476 }*/ + char ctime[12]; /*@r{ 488 }*/ + char mfill[8]; /*@r{ 500 }*/ + char xmagic[4]; /*@r{ 508 "tar" }*/ +@}; + +struct star_ext_header +@{ + struct sparse sp[SPARSES_IN_STAR_EXT_HEADER]; + char isextended; +@}; + |