Dogcows Code - chaz/tar/blob - README

   1 Please glance through *all* sections of this
   2 `README' file before starting configuration.  Also make sure you read files
   3 `ABOUT-NLS' and `INSTALL' if you are not familiar with them already.
   4
   5 If you got the `tar' distribution in `shar' format, time stamps ought to be
   6 properly restored; do not ignore such complaints at `unshar' time.
   7
   8 GNU `tar' saves many files together into a single tape or disk
   9 archive, and can restore individual files from the archive.  It includes
  10 multivolume support, the ability to archive sparse files, automatic archive
  11 compression/decompression, remote archives and special features that allow
  12 `tar' to be used for incremental and full backups.  This distribution
  13 also includes `rmt', the remote tape server.  The `mt' tape drive control
  14 program is in the GNU `cpio' distribution.
  15
  16 GNU `tar' is derived from John Gilmore's public domain `tar'.
  17
  18 See file `ABOUT-NLS' for how to customize this program to your language.
  19 See file `BACKLOG' for a summary of pending mail and articles.
  20 See file `COPYING' for copying conditions.
  21 See file `INSTALL' for compilation and installation instructions.
  22 See file `PORTS' for various ports of GNU tar to non-Unix systems.
  23 See file `NEWS' for a list of major changes in the current release.
  24 See file `THANKS' for a list of contributors.
  25
  26 Besides those configure options documented in files `INSTALL' and
  27 `ABOUT-NLS', an extra option may be accepted after `./configure':
  28
  29 * `--disable-largefile' omits support for large files, even if the
  30 operating system supports large files.  Typically, large files are
  31 those larger on 2 GB on a 32-bit host.
  32
  33 The default archive device is now `stdin' on read and `stdout' on write.
  34 The installer can still override this by presetting `DEFAULT_ARCHIVE'
  35 in the environment before configuring (the behavior of `-[0-7]' or
  36 `-[0-7]lmh' options in `tar' are then derived automatically).  Similarly,
  37 `DEFAULT_BLOCKING' can be preset to something else than 20.
  38
  39 For comprehensive modifications to GNU tar, you might need tools beyond
  40 those used in simple installations.  Fully install GNU m4 1.4 first,
  41 and only then, Autoconf 2.13 or later.  Install Perl, then Automake
  42 1.4 or later.  You might need Bison 1.28 or later, and GNU tar itself.
  43 All are available on GNU archive sites, like in
  44 ftp://ftp.gnu.org/pub/gnu/.
  45
  46 Send bug reports to `bug-tar@gnu.org'.  (Beware, old-timers: it is
  47 `@gnu', not `@prep'; and not `bug-gnu-utils' anymore.)  A bug report is
  48 an adequate description of the problem: your input, what you expected,
  49 what you got, and why this is wrong.  Diffs are welcome, but they only
  50 describe a solution, from which the problem might be uneasy to infer.
  51 If needed, submit actual data files with your report.  Small data files
  52 are preferred.  Big files may sometimes be necessary, but do not send them
  53 to the report address; rather take special arrangement with the maintainer.
  54
  55 Your feedback will help us to make a better and more portable package.
  56 Consider documentation errors as bugs, and report them as such.  If you
  57 develop anything pertaining to `tar' or have suggestions, let us know
  58 and share your findings by writing at `tar-forum@iro.umontreal.ca'.
  59
  60 .--------------------.
  61 | Installation hints |
  62 `--------------------'
  63
  64 Here are a few hints which might help installing `tar' on some systems.
  65
  66 * Static linking.
  67
  68 Some platform will, by default, prepare a smaller `tar' executable
  69 which depends on shared libraries.  Since GNU `tar' may be used for
  70 system-level backups and disaster recovery, installers might prefer to
  71 force static linking, making a bigger `tar' executable maybe, but able to
  72 work standalone, in situations where shared libraries are not available.
  73 The way to achieve static linking varies between systems.  Set LDFLAGS
  74 to a value from the table below, before configuration (see `INSTALL').
  75
  76         Platform        Compiler        LDFLAGS
  77
  78         (any)           Gnu C           -static
  79         AIX             (vendor)        "-bnso -bI:/lib/syscalls.exp"
  80         HPUX            (vendor)        -Wl,-a,archive
  81         IRIX            (vendor)        -non_shared
  82         OSF             (vendor)        -non_shared
  83         SCO 3.2v5       (vendor)        -dn
  84         Solaris         (vendor)        -Bstatic
  85         SunOS           (vendor)        -Bstatic
  86
  87 * Failed `incremen.sh'.
  88
  89 In an NFS environment, lack of synchronization between machine clocks
  90 might create difficulties to any tool comparing dates and file time stamps,
  91 like `tar' in incremental dumps.  This has been a recurrent problem in
  92 GNU Makefiles for the last few years.  We would like a general solution.
  93
  94 * BSD compatibility matters.
  95
  96 Set LIBS to `-lbsd' before configuration (see `INSTALL') if the linker
  97 complains about `bsd_ioctl' (Slackware).  Also set CPPFLAGS to
  98 `-I/usr/include/bsd' if <sgtty.h> is not found (Slackware).
  99
 100 * OPENStep 4.2 swap files
 101
 102 Tar cannot read the file /private/vm/swapfile.front (even as root).
 103 This file is not a real file, but some kind of uncompressed view of
 104 the real compressed swap file; there is no reason to back it up, so
 105 the simplest workaround is to avoid tarring this file.
 106
 107 .------------------.
 108 | Special topics.  |
 109 `------------------'
 110
 111 Here are a few special matters about GNU `tar', not related to build
 112 matters.  See previous section for such.
 113
 114 * File attributes.
 115
 116 About *security*, it is probable that future releases of `tar' will have
 117 some behavior changed.  There are many pending suggestions to choose from.
 118 Today, extracting an archive not being `root', `tar' will restore suid/sgid
 119 bits on files but owned by the extracting user.  `root' automatically gets
 120 a lot of special privileges, `-p' might later become required to get them.
 121
 122 GNU `tar' does not properly restore symlink attributes.  Various systems
 123 implement flavors of symbolic links showing different behavior and
 124 properties.  We did not successfully sorted all these out yet.  Currently,
 125 the `lchown' call will be used if available, but that's all.
 126
 127 * POSIX compliance.
 128
 129 GNU `tar' implements an early draft of the POSIX 1003.1 `ustar' standard
 130 which is different from the final standard.  This will be progressively
 131 corrected over the incoming few years.  Don't be mislead by the mere
 132 existence of the --posix option.  Later releases will become able to
 133 read truly POSIX archives, and also to produce them under option.  (Also,
 134 if you look at the internals, don't take the GNU extensions you see for
 135 granted, as they are planned to change.)  GNU tar 2.0 will produce POSIX
 136 archives by default, but there is a long way before we get there.
 137
 138 * What's next?
 139
 140 The emphasis from 1.11.2 to 1.14 has been on solving the main portability,
 141 execution or usability bugs.  This was accompanied all over with an
 142 internal cleanup in the sources, and the reassembly of a `tar' manual.
 143
 144 The `BACKLOG' file shows approximate priorities of the many pending
 145 problems and suggestions.  Besides pending problems and all other matters
 146 listed above, the cleanup is planned to continue and extend to the general
 147 organization of the code, preparing a long time in advance for a possible
 148 merge of the `cpio' and `tar' distributions, into some common `paxutils'.
 149 We also want to address some long-awaited performance issues (for example:
 150 double buffering) or enhancements (for example: per-file compression).