Dogcows Code - chaz/tar/blob - README

   1 Here is GNU `tar' 1.12.  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, timestamps 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', a few extra options may be accepted after `./configure':
  28
  29 * `--with-included-malloc' or `--without-included-malloc' may override
  30 the automatic choice made by `configure' about using included GNU malloc.
  31
  32 * `--with-dmalloc' is a debugging option for looking at memory management
  33 problems, it prerequires Gray Watson's package, which is available as
  34 `ftp://ftp.letters.com/src/dmalloc/dmalloc.tar.gz'.
  35
  36 The default archive device is now `stdin' on read and `stdout' on write.
  37 The installer can still override this by presetting `DEFAULT_ARCHIVE'
  38 in the environment before configuring (the behavior of `-[0-7]' or
  39 `-[0-7]lmh' options in `tar' are then derived automatically).  Similarly,
  40 `DEFAULT_BLOCKING' can be preset to something else than 20.
  41
  42 For comprehensive modifications to GNU tar, you might need tools beyond
  43 those used in simple installations.  Fully install GNU m4 1.4 first,
  44 and only then, Autoconf 2.12 with officious patches held in `AC-PATCHES'.
  45 Install Perl, then Automake 1.1n with officious patches in `AM-PATCHES'.
  46 You might need Bison 1.25 with officious patches in `BI-PATCHES' (but yacc
  47 and byacc may be OK for you), and GNU tar itself.  All are available on
  48 GNU archive sites, like in ftp://prep.ai.mit.edu/pub/gnu/, but Automake
  49 is still ftp://ftp.cygnus.com/pub/tromey/automake-1.1n.tar.gz.
  50
  51 Send bug reports to `tar-bugs@gnu.ai.mit.edu'.  (Beware, old-timers: it is
  52 `@gnu', not `@prep'; and not `bug-gnu-utils' anymore.)  A bug report is
  53 an adequate description of the problem: your input, what you expected,
  54 what you got, and why this is wrong.  Diffs are welcome, but they only
  55 describe a solution, from which the problem might be uneasy to infer.
  56 If needed, submit actual data files with your report.  Small data files
  57 are preferred.  Big files may sometimes be necessary, but do not send them
  58 to the report address; rather take special arrangement with the maintainer.
  59
  60 Your feedback will help us to make a better and more portable package.
  61 Consider documentation errors as bugs, and report them as such.  If you
  62 develop anything pertaining to `tar' or have suggestions, let us know
  63 and share your findings by writing at `tar-forum@iro.umontreal.ca'.
  64
  65 .--------------------.
  66 | Installation hints |
  67 `--------------------'
  68
  69 Here are a few hints which might help installing `tar' on some systems.
  70
  71 * Static linking.
  72
  73 Some platform will, by default, prepare a smaller `tar' executable
  74 which depends on shared libraries.  Since GNU `tar' may be used for
  75 system-level backups and disaster recovery, installers might prefer to
  76 force static linking, making a bigger `tar' executable maybe, but able to
  77 work standalone, in situations where shared libraries are not available.
  78 The way to achieve static linking varies between systems.  Set LDFLAGS
  79 to a value from the table below, before configuration (see `INSTALL').
  80
  81         Platform        Compiler        LDFLAGS
  82
  83         (any)           Gnu C           -static
  84         AIX             (vendor)        "-bnso -bI:/lib/syscalls.exp"
  85         HPUX            (vendor)        -Wl,-a,archive
  86         IRIX            (vendor)        -non_shared
  87         OSF             (vendor)        -non_shared
  88         SCO 3.2v5       (vendor)        -dn
  89         Solaris         (vendor)        -Bstatic
  90         SunOS           (vendor)        -Bstatic
  91
  92 * Failed `incremen.sh'.
  93
  94 In an NFS environment, lack of synchronisation between machine clocks
  95 might create difficulties to any tool comparing dates and file timestamps,
  96 like `tar' in incremental dumps.  This has been a recurrent problem in
  97 GNU Makefiles for the last few years.  We would like a general solution.
  98
  99 * BSD compatibility matters.
 100
 101 Set LIBS to `-lbsd' before configuration (see `INSTALL') if the linker
 102 complains about undefined `valloc' (AIX) or `bsd_ioctl' (Slackware).
 103 Also set CPPFLAGS to `-I/usr/include/bsd/sys' before configuration to
 104 solve dirent problems (NeXT), or to `-I/usr/include/bsd' if <sgtty.h>
 105 is not found (Slackware).
 106
 107 * `union wait' problems.
 108
 109 Configuration of `union wait' does not always take the best decision.
 110 If you have this problem, edit file `config.cache' after configuration,
 111 find the line about `tar_cv_header_union_wait', change `yes' by `no'
 112 or vice-versa, execute `./config.status', then launch `make'.
 113
 114 * `%lld' unsupported in `printf'.
 115
 116 GNU C has `long long', but the underneath C library might not support
 117 the `%lld' format.  If you have this problem, edit file `config.cache'
 118 after configuration, find the line about `ac_cv_sizeof_long_long, change
 119 `8' by `0', execute `./config.status', then launch `make'.
 120
 121 * FreeBSD users -- `configure' fails.
 122
 123 It has been reported that `configure' does not run on FreeBSD 2.1.7,
 124 because of a buggy `sh'.  It works using `bash', however.
 125
 126 * ISC users -- `S_*' symbols undefined.
 127
 128 On ISC 4.1mu, POSIX environment, set CFLAGS to `-posix' and CPPFLAGS to
 129 `-D_SYSV3' before configuration (see `INSTALL').  This will trigger the
 130 definition of a few `S_' prefixed symbols from <sys/stat.h>.
 131
 132 * Ultrix users -- broken `make'.
 133
 134 It seems that Ultrix make does not correctly handle shell commands
 135 having logical connectives in them.  Use `s5make' if you have it, try
 136 `PROG_ENV=SYSTEM_FIVE make' (works on Ultrix 4.4), or install GNU Make.
 137
 138 .------------------.
 139 | Special topics.  |
 140 `------------------'
 141
 142 Here are a few special matters about GNU `tar', not related to build
 143 matters.  See previous section for such.
 144
 145 * File attributes.
 146
 147 About *security*, it is probable that future releases of `tar' will have
 148 some behaviour changed.  There are many pending suggestions to choose from.
 149 Today, extracting an archive not being `root', `tar' will restore suid/sgid
 150 bits on files but owned by the extracting user.  `root' automatically gets
 151 a lot of special priviledges, `-p' might later become required to get them.
 152
 153 GNU `tar' does not properly restore symlink attributes.  Various systems
 154 implement flavours of symbolic links showing different behaviour and
 155 properties.  We did not successfully sorted all these out yet.  Currently,
 156 the `lchown' call will be used if available, but that's all.
 157
 158 * POSIX compliance.
 159
 160 GNU `tar' implements an early draft of the POSIX 1003.1 `ustar' standard
 161 which is different from the final standard.  This will be progressively
 162 corrected over the incoming few years.  Don't be mislead by the mere
 163 existence of the --posix option.  Later releases will become able to
 164 read truly POSIX archives, and also to produce them under option.  (Also,
 165 if you look at the internals, don't take the GNU extensions you see for
 166 granted, as they are planned to change.)  GNU tar 2.0 will produce POSIX
 167 archives by default, but there is a long way before we get there.
 168
 169 * What's next?
 170
 171 The emphasis from 1.11.2 to 1.12 has been on solving the main portability,
 172 execution or usability bugs.  This was accompanied all over with an
 173 internal cleanup in the sources, and the reassembly of a `tar' manual.
 174
 175 The `BACKLOG' file shows an approximative priorisation of the many pending
 176 problems and suggestions.  Besides pending problems and all other matters
 177 listed above, the cleanup is planned to continue and extend to the general
 178 organisation of the code, preparing a long time in advance for a possible
 179 merge of the `cpio' and `tar' distributions, into some common `paxutils'.
 180 We also want to address some long-awaited performance issues (for example:
 181 double buffering) or enhancements (for example: per-file compression).