Dogcows Code - chaz/tar/blob - README

   1 README for GNU tar
   2 See the end of file for copying conditions.
   3
   4 * Introduction
   5
   6 Please glance through *all* sections of this
   7 `README' file before starting configuration.  Also make sure you read files
   8 `ABOUT-NLS' and `INSTALL' if you are not familiar with them already.
   9
  10 If you got the `tar' distribution in `shar' format, time stamps ought to be
  11 properly restored; do not ignore such complaints at `unshar' time.
  12
  13 GNU `tar' saves many files together into a single tape or disk
  14 archive, and can restore individual files from the archive.  It includes
  15 multivolume support, the ability to archive sparse files, automatic archive
  16 compression/decompression, remote archives and special features that allow
  17 `tar' to be used for incremental and full backups.  This distribution
  18 also includes `rmt', the remote tape server.  The `mt' tape drive control
  19 program is in the GNU `cpio' distribution.
  20
  21 GNU `tar' is derived from John Gilmore's public domain `tar'.
  22
  23 See file `ABOUT-NLS' for how to customize this program to your language.
  24 See file `COPYING' for copying conditions.
  25 See file `INSTALL' for compilation and installation instructions.
  26 See file `PORTS' for various ports of GNU tar to non-Unix systems.
  27 See file `NEWS' for a list of major changes in the current release.
  28 See file `THANKS' for a list of contributors.
  29
  30 Besides those configure options documented in files `INSTALL' and
  31 `ABOUT-NLS', an extra option may be accepted after `./configure':
  32
  33 * Install
  34
  35 ** Selecting the default archive format.
  36
  37 The default archive format is GNU, this can be overridden by
  38 presetting DEFAULT_ARCHIVE_FORMAT while configuring. The allowed
  39 values are GNU, V7, OLDGNU, USTAR and POSIX.
  40
  41 ** Selecting the default archive device
  42
  43 The default archive device is now `stdin' on read and `stdout' on write.
  44 The installer can still override this by presetting `DEFAULT_ARCHIVE'
  45 in the environment before configuring (the behavior of `-[0-7]' or
  46 `-[0-7]lmh' options in `tar' are then derived automatically).  Similarly,
  47 `DEFAULT_BLOCKING' can be preset to something else than 20.
  48
  49 ** Selecting full pathname of the "rmt" binary.
  50
  51 Previous versions of tar always looked for "rmt" binary using
  52 hardcoded path "/etc/rmt". However, the "rmt" program included
  53 in the distribution was installed under "$prefix/libexec/rmt".
  54 To fix this discrepancy, tar now looks for "$prefix/libexec/rmt".
  55 If you do not want this behavior, specify full path name of
  56 "rmt" binary using DEFAULT_RMT_COMMAND variable, e.g.:
  57
  58 ./configure DEFAULT_RMT_COMMAND=/etc/rmt
  59
  60 ** Installing backup scripts.
  61
  62 This version of tar is shipped with the shell scripts for producing
  63 incremental backups (dumps) and restoring filesystems from them.
  64 The name of the backup script is "backup". The name of the
  65 restore script is "restore". They are installed in "$prefix/sbin"
  66 directory.
  67
  68 Use option --enable-backup-scripts to compile and install these
  69 scripts.
  70
  71 ** `--disable-largefile' omits support for large files, even if the
  72 operating system supports large files.  Typically, large files are
  73 those larger on 2 GB on a 32-bit host.
  74
  75 * Installation hints
  76
  77 Here are a few hints which might help installing `tar' on some systems.
  78
  79 ** gzip and bzip2.
  80
  81 GNU tar uses the gzip and bzip2 programs to read and write compressed
  82 archives.  If you don't have these programs already, you need to
  83 install them.  Their sources can be found at:
  84
  85 ftp://ftp.gnu.org/gnu/gzip/
  86 http://sourceware.cygnus.com/bzip2/
  87
  88 If you see the following symptoms:
  89
  90    $ tar -xzf file.tar.gz
  91    gzip: stdin: decompression OK, trailing garbage ignored
  92    tar: Child returned status 2
  93
  94 then you have encountered a gzip incompatibility that should be fixed
  95 in gzip test version 1.3, which as of this writing is available at
  96 <ftp://alpha.gnu.org/gnu/gzip/>.  You can work around the
  97 incompatibility by using a shell command like
  98  `gzip -d <file.tar.gz | tar -xzf -'.
  99
 100 ** Solaris issues.
 101
 102 GNU tar exercises many features that can cause problems with older GCC
 103 versions.  In particular, GCC 2.8.1 (sparc, -O1 or -O2) is known to
 104 miscompile GNU tar.  No compiler-related problems have been reported
 105 when using GCC 2.95.2 or later.
 106
 107 Recent versions of Solaris tar sport a new -E option to generate
 108 extended headers in an undocumented format.  GNU tar does not
 109 understand these headers.
 110
 111 ** Static linking.
 112
 113 Some platform will, by default, prepare a smaller `tar' executable
 114 which depends on shared libraries.  Since GNU `tar' may be used for
 115 system-level backups and disaster recovery, installers might prefer to
 116 force static linking, making a bigger `tar' executable maybe, but able to
 117 work standalone, in situations where shared libraries are not available.
 118 The way to achieve static linking varies between systems.  Set LDFLAGS
 119 to a value from the table below, before configuration (see `INSTALL').
 120
 121         Platform        Compiler        LDFLAGS
 122
 123         (any)           Gnu C           -static
 124         AIX             (vendor)        -bnso -bI:/lib/syscalls.exp
 125         HPUX            (vendor)        -Wl,-a,archive
 126         IRIX            (vendor)        -non_shared
 127         OSF             (vendor)        -non_shared
 128         SCO 3.2v5       (vendor)        -dn
 129         Solaris         (vendor)        -Bstatic
 130         SunOS           (vendor)        -Bstatic
 131
 132 ** Failed tests `ignfail.sh' or `incremen.sh'.
 133
 134 In an NFS environment, lack of synchronization between machine clocks
 135 might create difficulties to any tool comparing dates and file time stamps,
 136 like `tar' in incremental dumps.  This has been a recurrent problem with
 137 GNU Make for the last few years.  We would like a general solution.
 138
 139 ** BSD compatibility matters.
 140
 141 Set LIBS to `-lbsd' before configuration (see `INSTALL') if the linker
 142 complains about `bsd_ioctl' (Slackware).  Also set CPPFLAGS to
 143 `-I/usr/include/bsd' if <sgtty.h> is not found (Slackware).
 144
 145 ** OPENStep 4.2 swap files
 146
 147 Tar cannot read the file /private/vm/swapfile.front (even as root).
 148 This file is not a real file, but some kind of uncompressed view of
 149 the real compressed swap file; there is no reason to back it up, so
 150 the simplest workaround is to avoid tarring this file.
 151
 152 * Special topics
 153
 154 Here are a few special matters about GNU `tar', not related to build
 155 matters.  See previous section for such.
 156
 157 ** File attributes.
 158
 159 About *security*, it is probable that future releases of `tar' will have
 160 some behavior changed.  There are many pending suggestions to choose from.
 161 Today, extracting an archive not being `root', `tar' will restore suid/sgid
 162 bits on files but owned by the extracting user.  `root' automatically gets
 163 a lot of special privileges, `-p' might later become required to get them.
 164
 165 GNU `tar' does not properly restore symlink attributes.  Various systems
 166 implement flavors of symbolic links showing different behavior and
 167 properties.  We did not successfully sorted all these out yet.  Currently,
 168 the `lchown' call will be used if available, but that's all.
 169
 170 ** POSIX compliance.
 171
 172 GNU `tar' is able to create archive in the following formats:
 173
 174   *** The format of UNIX version 7
 175   *** POSIX.1-1988 format, also known as "ustar format"
 176   *** POSIX.1-2001 format, also known as "pax format"
 177   *** Old GNU format (described below)
 178
 179 In addition to those, GNU `tar' is also able to read archives
 180 produced by `star' archiver.
 181
 182 A so called `Old GNU' format is based on an early draft of the
 183 POSIX 1003.1 `ustar' standard which is different from the final
 184 standard. It defines its extensions (such as incremental backups
 185 and handling of the long file names) in a way incompatible with
 186 any existing tar archive format, therefore the use of old GNU
 187 format is strongly discouraged.
 188
 189 Please read the file NEWS for more information about POSIX compliance
 190 and new `tar' features.
 191
 192 * What's next?
 193
 194 GNU tar will be merged into GNU paxutils: a project containing
 195 several utilities related to creating and handling archives in
 196 various formats. The project will include tar, cpio and pax
 197 utilities.
 198
 199 * Bug reporting.
 200
 201 Send bug reports to <bug-tar@gnu.org>.  A bug report should contain
 202 an adequate description of the problem, your input, what you expected,
 203 what you got, and why this is wrong.  Diffs are welcome, but they only
 204 describe a solution, from which the problem might be uneasy to infer.
 205 If needed, submit actual data files with your report.  Small data files
 206 are preferred.  Big files may sometimes be necessary, but do not send them
 207 to the report address; rather take special arrangement with the maintainer.
 208
 209 Your feedback will help us to make a better and more portable package.
 210 Consider documentation errors as bugs, and report them as such.  If you
 211 develop anything pertaining to `tar' or have suggestions, let us know
 212 and share your findings by writing to <bug-tar@gnu.org>.
 213
 214 \f
 215 * Copying
 216
 217         Copyright (C) 1990, 1991, 1992, 1994, 1997, 1998, 1999, 2000,
 218         2001, 2003, 2004 Free Software Foundation, Inc.
 219
 220         This file is part of GNU tar.
 221
 222         GNU tar is free software; you can redistribute it and/or modify
 223         it under the terms of the GNU General Public License as published by
 224         the Free Software Foundation; either version 2, or (at your option)
 225         any later version.
 226
 227         GNU tar is distributed in the hope that it will be useful,
 228         but WITHOUT ANY WARRANTY; without even the implied warranty of
 229         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 230         GNU General Public License for more details.
 231
 232         You should have received a copy of the GNU General Public License
 233         along with tar; see the file COPYING.  If not, write to
 234         the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 235         Boston, MA 02111-1307, USA.
 236
 237 \f
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