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 in the
  52 directory "/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_DIR variable, e.g.:
  57
  58 ./configure DEFAULT_RMT_DIR=/etc
  59
  60 If you already have a copy of "rmt" installed and wish to use it
  61 instead of the version supplied with the distribution, use --with-rmt
  62 option:
  63
  64 ./configure --with-rmt=/etc/rmt
  65
  66 This will also disable building the included version of rmt.
  67
  68 ** Installing backup scripts.
  69
  70 This version of tar is shipped with the shell scripts for producing
  71 incremental backups (dumps) and restoring filesystems from them.
  72 The name of the backup script is "backup". The name of the
  73 restore script is "restore". They are installed in "$prefix/sbin"
  74 directory.
  75
  76 Use option --enable-backup-scripts to compile and install these
  77 scripts.
  78
  79 ** `--disable-largefile' omits support for large files, even if the
  80 operating system supports large files.  Typically, large files are
  81 those larger on 2 GB on a 32-bit host.
  82
  83 * Installation hints
  84
  85 Here are a few hints which might help installing `tar' on some systems.
  86
  87 ** gzip and bzip2.
  88
  89 GNU tar uses the gzip and bzip2 programs to read and write compressed
  90 archives.  If you don't have these programs already, you need to
  91 install them.  Their sources can be found at:
  92
  93 ftp://ftp.gnu.org/gnu/gzip/
  94 http://sourceware.cygnus.com/bzip2/
  95
  96 If you see the following symptoms:
  97
  98    $ tar -xzf file.tar.gz
  99    gzip: stdin: decompression OK, trailing garbage ignored
 100    tar: Child returned status 2
 101
 102 then you have encountered a gzip incompatibility that should be fixed
 103 in gzip test version 1.3, which as of this writing is available at
 104 <ftp://alpha.gnu.org/gnu/gzip/>.  You can work around the
 105 incompatibility by using a shell command like
 106  `gzip -d <file.tar.gz | tar -xzf -'.
 107
 108 ** Solaris issues.
 109
 110 GNU tar exercises many features that can cause problems with older GCC
 111 versions.  In particular, GCC 2.8.1 (sparc, -O1 or -O2) is known to
 112 miscompile GNU tar.  No compiler-related problems have been reported
 113 when using GCC 2.95.2 or later.
 114
 115 Recent versions of Solaris tar sport a new -E option to generate
 116 extended headers in an undocumented format.  GNU tar does not
 117 understand these headers.
 118
 119 ** Static linking.
 120
 121 Some platform will, by default, prepare a smaller `tar' executable
 122 which depends on shared libraries.  Since GNU `tar' may be used for
 123 system-level backups and disaster recovery, installers might prefer to
 124 force static linking, making a bigger `tar' executable maybe, but able to
 125 work standalone, in situations where shared libraries are not available.
 126 The way to achieve static linking varies between systems.  Set LDFLAGS
 127 to a value from the table below, before configuration (see `INSTALL').
 128
 129         Platform        Compiler        LDFLAGS
 130
 131         (any)           Gnu C           -static
 132         AIX             (vendor)        -bnso -bI:/lib/syscalls.exp
 133         HPUX            (vendor)        -Wl,-a,archive
 134         IRIX            (vendor)        -non_shared
 135         OSF             (vendor)        -non_shared
 136         SCO 3.2v5       (vendor)        -dn
 137         Solaris         (vendor)        -Bstatic
 138         SunOS           (vendor)        -Bstatic
 139
 140 ** Failed tests `ignfail.sh' or `incremen.sh'.
 141
 142 In an NFS environment, lack of synchronization between machine clocks
 143 might create difficulties to any tool comparing dates and file time stamps,
 144 like `tar' in incremental dumps.  This has been a recurrent problem with
 145 GNU Make for the last few years.  We would like a general solution.
 146
 147 ** BSD compatibility matters.
 148
 149 Set LIBS to `-lbsd' before configuration (see `INSTALL') if the linker
 150 complains about `bsd_ioctl' (Slackware).  Also set CPPFLAGS to
 151 `-I/usr/include/bsd' if <sgtty.h> is not found (Slackware).
 152
 153 ** OPENStep 4.2 swap files
 154
 155 Tar cannot read the file /private/vm/swapfile.front (even as root).
 156 This file is not a real file, but some kind of uncompressed view of
 157 the real compressed swap file; there is no reason to back it up, so
 158 the simplest workaround is to avoid tarring this file.
 159
 160 * Special topics
 161
 162 Here are a few special matters about GNU `tar', not related to build
 163 matters.  See previous section for such.
 164
 165 ** File attributes.
 166
 167 About *security*, it is probable that future releases of `tar' will have
 168 some behavior changed.  There are many pending suggestions to choose from.
 169 Today, extracting an archive not being `root', `tar' will restore suid/sgid
 170 bits on files but owned by the extracting user.  `root' automatically gets
 171 a lot of special privileges, `-p' might later become required to get them.
 172
 173 GNU `tar' does not properly restore symlink attributes.  Various systems
 174 implement flavors of symbolic links showing different behavior and
 175 properties.  We did not successfully sorted all these out yet.  Currently,
 176 the `lchown' call will be used if available, but that's all.
 177
 178 ** POSIX compliance.
 179
 180 GNU `tar' is able to create archive in the following formats:
 181
 182   *** The format of UNIX version 7
 183   *** POSIX.1-1988 format, also known as "ustar format"
 184   *** POSIX.1-2001 format, also known as "pax format"
 185   *** Old GNU format (described below)
 186
 187 In addition to those, GNU `tar' is also able to read archives
 188 produced by `star' archiver.
 189
 190 A so called `Old GNU' format is based on an early draft of the
 191 POSIX 1003.1 `ustar' standard which is different from the final
 192 standard. It defines its extensions (such as incremental backups
 193 and handling of the long file names) in a way incompatible with
 194 any existing tar archive format, therefore the use of old GNU
 195 format is strongly discouraged.
 196
 197 Please read the file NEWS for more information about POSIX compliance
 198 and new `tar' features.
 199
 200 * What's next?
 201
 202 GNU tar will be merged into GNU paxutils: a project containing
 203 several utilities related to creating and handling archives in
 204 various formats. The project will include tar, cpio and pax
 205 utilities.
 206
 207 * Bug reporting.
 208
 209 Send bug reports to <bug-tar@gnu.org>.  A bug report should contain
 210 an adequate description of the problem, your input, what you expected,
 211 what you got, and why this is wrong.  Diffs are welcome, but they only
 212 describe a solution, from which the problem might be uneasy to infer.
 213 If needed, submit actual data files with your report.  Small data files
 214 are preferred.  Big files may sometimes be necessary, but do not send them
 215 to the report address; rather take special arrangement with the maintainer.
 216
 217 Your feedback will help us to make a better and more portable package.
 218 Consider documentation errors as bugs, and report them as such.  If you
 219 develop anything pertaining to `tar' or have suggestions, let us know
 220 and share your findings by writing to <bug-tar@gnu.org>.
 221
 222 \f
 223 * Copying
 224
 225         Copyright (C) 1990, 1991, 1992, 1994, 1997, 1998, 1999, 2000,
 226         2001, 2003, 2004 Free Software Foundation, Inc.
 227
 228         This file is part of GNU tar.
 229
 230         GNU tar is free software; you can redistribute it and/or modify
 231         it under the terms of the GNU General Public License as published by
 232         the Free Software Foundation; either version 2, or (at your option)
 233         any later version.
 234
 235         GNU tar is distributed in the hope that it will be useful,
 236         but WITHOUT ANY WARRANTY; without even the implied warranty of
 237         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 238         GNU General Public License for more details.
 239
 240         You should have received a copy of the GNU General Public License
 241         along with tar; see the file COPYING.  If not, write to
 242         the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 243         Boston, MA 02110-1301, USA.
 244
 245 \f
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