2 See the end of file for copying conditions.
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.
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.
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.
21 GNU `tar' is derived from John Gilmore's public domain `tar'.
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.
30 Besides those configure options documented in files `INSTALL' and
31 `ABOUT-NLS', an extra option may be accepted after `./configure':
35 ** Selecting the default archive format.
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.
41 ** Selecting the default archive device
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.
49 ** Selecting full pathname of the "rmt" binary.
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.:
58 ./configure DEFAULT_RMT_DIR=/etc
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
64 ./configure --with-rmt=/etc/rmt
66 This will also disable building the included version of rmt.
68 ** Installing backup scripts.
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"
76 Use option --enable-backup-scripts to compile and install these
79 ** `--disable-largefile' omits support for large files, even if the
80 operating system supports large files. Typically, large files are
81 those larger than 2 GB on a 32-bit host.
85 Here are a few hints which might help installing `tar' on some systems.
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:
93 ftp://ftp.gnu.org/gnu/gzip/
94 http://sourceware.cygnus.com/bzip2/
96 If you see the following symptoms:
98 $ tar -xzf file.tar.gz
99 gzip: stdin: decompression OK, trailing garbage ignored
100 tar: Child returned status 2
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 -'.
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.
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.
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').
129 Platform Compiler LDFLAGS
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
140 ** Failed tests `ignfail.sh' or `incremen.sh'.
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.
147 ** BSD compatibility matters.
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).
153 ** OPENStep 4.2 swap files
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.
162 Here are a few special matters about GNU `tar', not related to build
163 matters. See previous section for such.
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.
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.
180 GNU `tar' is able to create archive in the following formats:
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)
187 In addition to those, GNU `tar' is also able to read archives
188 produced by `star' archiver.
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.
197 Please read the file NEWS for more information about POSIX compliance
198 and new `tar' features.
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
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.
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>.
225 Copyright (C) 1990, 1991, 1992, 1994, 1997, 1998, 1999, 2000,
226 2001, 2003, 2004, 2007 Free Software Foundation, Inc.
228 This file is part of GNU tar.
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 3, or (at your option)
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.
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.
248 paragraph-separate: "[
\f]*$"
249 version-control: never