File: sharutils.info, Node: Top, Next: Introduction, Prev: (dir), Up: (dir)
GNU `shar' utilities
********************
GNU `shar' makes so-called shell archives out of many files,
preparing them for transmission by electronic mail services. GNU
`unshar' helps unpacking shell archives after reception. This is
release 4.1.9.
* Menu:
* Introduction:: Introduction to both programs
* shar invocation:: Invoking the `shar' program
* unshar invocation:: Invoking the `unshar' program
* Miscellaneous:: Miscellaneous considerations
-- The Detailed Node Listing --
Creating shell archives
* Selecting:: Selecting files
* Splitting:: Splitting output
* Headers:: Controlling the shar headers
* Stocking:: Selecting how files are stocked
* Transmission:: Protecting against transmission
* Kinds:: Producing different kinds of shar
File: sharutils.info, Node: Introduction, Next: shar invocation, Prev: Top, Up: Top
Introduction to both programs
*****************************
GNU `shar' makes so-called shell archives out of many files,
preparing them for transmission by electronic mail services. A "shell
archive" is a collection of files that can be unpacked by `/bin/sh'. A
wide range of features provide extensive flexibility in manufacturing
shars and in specifying shar *smartness*. For example, `shar' may
compress files, uuencode binary files, split long files and construct
multi-part mailings, ensure correct unsharing order, and provide
simplistic checksums. *Note shar invocation::.
GNU `unshar' scans a set of mail messages looking for the start of
shell archives. It will automatically strip off the mail headers and
other introductory text. The archive bodies are then unpacked by a
copy of the shell. `unshar' may also process files containing
concatenated shell archives. *Note unshar invocation::.
GNU `shar' has a long history. All along this long road, numerous
users contributed various improvements. The file `THANKS', from the
GNU `shar' distribution, contain all names still having valid email
addresses, as far as we know.
Please help me getting the history straight, for the following
information is approximative. James Gosling wrote the public domain
`shar 1.x'. William Davidsen rewrote it as `shar 2.x'. Warren Tucker
brought modifications and called it `shar 3.x'. Richard Gumpertz
maintained it until 1990. Franc,ois Pinard, from the public domain
`shar 3.49', made `GNU shar 4.x', in 1994. Some modules and other code
sections were freely borrowed from other GNU distributions, bringing
this `shar' under the terms of the GNU General Public License.
Your feedback helps us to make a better and more portable product.
Mail suggestions and bug reports (including documentation errors) for
these programs to `'.
File: sharutils.info, Node: shar invocation, Next: unshar invocation, Prev: Introduction, Up: Top
Invoking the `shar' program
***************************
The format of the `shar' command is one of:
shar [ OPTION ] ... FILE ...
shar -S [ OPTION ] ...
In the first form, the file list is given as command arguments. In
the second form, the file list is read from standard input. The
resulting archive is sent to standard output unless the `-o' option is
given.
Options can be given in any order. Some options depend on each
other: the `-o' option is required if the `-l' or `-L' option is used.
The `-n' option is required if the `-a' option is used. Also see `-V'
below.
Some options are special purpose:
`--help'
Print a help summary on standard output, then immediately exits.
`--version'
Print the version number of the program on standard output, then
immediately exits.
`-q'
`--quiet'
Verbose *off* at `shar' time. Messages are usually issued on
standard error to let the user follow the progress, while making
the archives. This option inhibits these messages.
* Menu:
* Selecting:: Selecting files
* Splitting:: Splitting output
* Headers:: Controlling the shar headers
* Stocking:: Selecting how files are stocked
* Transmission:: Protecting against transmission
* Kinds:: Producing different kinds of shar
File: sharutils.info, Node: Selecting, Next: Splitting, Prev: shar invocation, Up: shar invocation
Selecting files
===============
`-p'
`--intermix-type'
Allow positional parameter options. The options `-M', `-B', `-T',
`-z' and `-Z' may be embedded, and files to the right of the
option will be processed in the specified mode. Without the `-p'
option, embedded options would be interpreted as file names.
*Note Stocking:: for more information on these options.
`-S'
`--stdin-file-list'
Read list of files to be packed from the standard input rather
than from the command line. Input must be one file name per line.
This switch is especially useful when the command line will not
hold the list of files to be packed. For example:
find . -type f -print | shar -S -o /tmp/big.shar
If `-p' is specified on the command line, then the options `-M',
`-B', `-T', `-z' and `-Z' may be included in the standard input
(on a line separate from file names). The maximum number of lines
of standard input, file names and options, may not exceed 1024.
File: sharutils.info, Node: Splitting, Next: Headers, Prev: Selecting, Up: shar invocation
Splitting output
================
`-o PREFIX'
`--output-prefix=PREFIX'
Save the archive to files `PREFIX.01' through `PREFIX.NNN' instead
of standard output. This option *must* be used when the `-l' or
the `-L' switches are used.
When PREFIX contains any `%' character, PREFIX is then interpreted
as a `sprintf' format, which should be able to display a single
decimal number. When PREFIX does not contain such a `%'
character, the string `.%02d' is internally appended.
`-l SIZE'
`--whole-size-limit=SIZE'
Limit the output file size to SIZE times 1024 bytes but don't
split input files. This allows the recipient of the shell archives
to unpack them in any order.
`-L SIZE'
`--split-size-limit=SIZE'
Limit output file size to SIZE times 1024 bytes and split files if
necessary. The archives created with this option must be unpacked
in the correct order. If the recipient of the shell archives
wants to put all of them in a single folder, she shall save them
in the correct order for `unshar', used with option `-e', to
unpack them all at once. *Note unshar invocation::.
For people used to saving all the shell archives into a single mail
folder, care must be taken to save them in the appropriate order.
For those having the appropriate tools (like Masanobu Umeda's
`rmailsort' package for GNU Emacs), shell archives can be saved in
any order, then sorted by increasing date (or send time) before
massive unpacking.
File: sharutils.info, Node: Headers, Next: Stocking, Prev: Splitting, Up: shar invocation
Controlling the shar headers
============================
`-n NAME'
`--archive-name=NAME'
Name of archive to be included in the header of the shar files.
Also see the `-a' switch further down.
`-s ADDRESS'
`--submitter=ADDRESS'
The `-s' option allows for overriding the email address for the
submitter, for when the default is not appropriate. The
automatically determined address looks like `USERNAME@HOSTNAME'.
`-a'
`--net-headers'
Allows automatic generation of headers:
Submitted-by: ADDRESS
Archive-name: NAME/partNN
The NAME must be given with the `-n' switch. If name includes a
`/', then `/part' isn't used. Thus `-n xyzzy' produces:
xyzzy/part01
xyzzy/part02
while `-n xyzzy/patch' produces:
xyzzy/patch01
xyzzy/patch02
and `-n xyzzy/patch01.' produces:
xyzzy/patch01.01
xyzzy/patch01.02
`-c'
`--cut-mark'
Start the shar with a cut line. A line saying `Cut here' is
placed at the start of each output file.
File: sharutils.info, Node: Stocking, Next: Transmission, Prev: Headers, Up: shar invocation
Selecting how files are stocked
===============================
`-T'
`--text-files'
Treat all files as text, regardless of their contents.
`-B'
`--uuencode'
Treat all files as binary, use `uuencode' prior to packing. This
increases the size of the archive. The recipient must have
`uudecode' in order to unpack.
Use of `uuencode' is not appreciated by many on the net, because
people like to readily see, by mere inspection of a shell archive,
what it is about.
`-M'
`--mixed-uuencode'
Mixed mode. Automatically determine if the files are text or
binary and archive correctly. Files found to be binary are
uuencoded prior to packing. This option is selected by default.
For a file is considered to be a text file, instead of a binary
file, all the following should be true simultaneously:
1. The file does not contain any ASCII control character besides
BS (backspace), HT (horizontal tab), LF (new line) or FF
(form feed).
2. The file does not contains a DEL (delete).
3. The file contains no character with its eighth-bit set.
4. The file, unless totally empty, terminates with a LF
(newline).
5. No line in the file contains more than 200 characters. For
counting purpose, lines are separated by a LF (newline).
`-z'
`--gzip'
Use `gzip' and `uuencode' on all files prior to packing. The
recipient must have `uudecode' and `gzip' (used with `-d') in
order to unpack.
Usage of `-z' in net shars will cause you to be flamed off the
earth.
`-g LEVEL'
`--level-for-gzip=LEVEL'
When doing compression, use `-LEVEL' as a parameter to `gzip'.
The `-g' option turns on the `-z' option by default. The default
value is 9, that is, maximum compression.
`-Z'
`--compress'
Use `compress' and `uuencode' on all files prior to packing. The
recipient must have `uudecode' and `compress' (used with `-d') in
order to unpack. Option `-C' is a synonymous for `-Z', but is
deprecated.
Usage of `-Z' in net shars will cause you to be flamed off the
earth.
`-b BITS'
`--bits-per-code=BITS'
When doing compression, use `-bX' as a parameter to `compress'.
The `-B' option turns on the `-Z' option by default. The default
value is 12, foreseeing the memory limitations of some `compress'
programs on smallish systems, at `unshar' time.
File: sharutils.info, Node: Transmission, Next: Kinds, Prev: Stocking, Up: shar invocation
Protecting against transmission errors
======================================
Transmission of shell archives is not always free of errors. So one
should make consistency checks on the receiving site. A very simple
(and unreliable) method is running the UNIX `wc' tool on the output
file. This can report the number of characters in the file.
As one can guess this does not catch all errors. Especially
changing of a character value does not change the computed check sum.
To achieve this goal better method were invented and standardized. One
very strong is MD5 (MD = message digests). This is standardized in RFC
1321. The produced shell scripts do not force the `md5sum' program to
be installed on the system. This is necessary because it is not yet
part of every UNIX. The program is however not necessary for producing
the shell archive.
`-w'
`--no-character-count'
Do *not* check with `wc -c' after unpack. The default is to check.
`-D'
`--no-md5-digest'
Do *not* check with `md5sum' after unpack. The default is to
check.
`-F'
`--force-prefix'
Prepend the prefix character to every line even if not required.
This option may slightly increase the size of the archive,
especially if `-B' or `-Z' is used. Normally, the prefix character
is `X'. If the parameter to the `-d' option starts with `X', then
the prefix character becomes `Y'.
`-d STRING'
`--here-delimiter=STRING'
Use STRING to delimit the files in the shar instead of `SHAR_EOF'.
This is for those who want to personalize their shar files.
File: sharutils.info, Node: Kinds, Prev: Transmission, Up: shar invocation
Producing different kinds of shars
==================================
`-V'
`--vanilla-operation'
This option produces "vanilla" shars which rely only upon the
existence of `echo', `test' and `sed' in the unpacking environment.
The `-V' disables options offensive to the "network cop" (or
"brown shirt"). It also changes the default from mixed mode `-M'
to text mode `-T'. Warnings are produced if option `-B', `-z',
`-Z', `-p' or `-M' is specified (any of which does or might
require `uudecode', `gzip' or `compress' in the unpacking
environment).
`-P'
`--no-piping'
In the shar file, use a temporary file to hold the file to
`uudecode', instead of using pipes. This option is mandatory when
you know the unpacking `uudecode' is unwilling to merely read its
standard input. Richard Marks wrote what is certainly the most
(in)famous of these, for MSDOS :-).
(Here is a side note from the maintainer. Why isnt't this option
the default? In the past history of `shar', it was decided that
piping was better, surely because it is less demanding on disk
space, and people seem to be happy with this. Besides, I think
that the `uudecode' from Richard Marks, on MSDOS, is wrong in
refusing to handle `stdin'. So far that I remember, he has the
strong opinion that a program without any parameters should give
its `--help' output. Besides that, should I say, his `uuencode'
and `uudecode' programs are full-featured, one of the most
complete set I ever saw. But Richard will not release his
sources, he wants to stay in control.)
`-x'
`--no-check-existing'
Overwrite existing files without checking. If neither `-x' nor
`-X' is specified, when unpacking itself, the shell archive will
check for and not overwrite existing files (unless `-c' is passed
as a parameter to the script when unpacking).
`-X'
`--query-user'
Interactively overwrite existing files.
Use of `-X' produces shars which *will* cause problems with some
`unshar'-style procedures, particularily when used together with
vanilla mode (`-V'). Use this feature mainly for archives to be
passed among agreeable parties. Certainly, `-X' is *not* for
shell archives which are to be submitted to Usenet or other public
networks.
The problem is that `unshar' programs or procedures often feed
`/bin/sh' from its standard input, thus putting `/bin/sh' and the
shell archive script in competition for input lines. As an
attempt to alleviate this problem, `shar' will try to detect if
`/dev/tty' exists at the receiving site and will use it to read
user replies. But this does not work in all cases, it may happen
that the receiving user will have to avoid using `unshar' programs
or procedures, and call `/bin/sh' directly. In vanilla mode,
using `/dev/tty' is not even attempted.
`-m'
`--no-timestamp'
Avoid generating `touch' commands to restore the file modification
dates when unpacking files from the archive.
When the timestamp relationship is not preserved, some files like
`configure' or `*.info' may be uselessly remade after unpacking.
This is why, when this option is not used, a special effort is
made to restore timestamps,
`-Q'
`--quiet-unshar'
Verbose *off* at `unshar' time. Disables the inclusion of
comments to be output when the archive is unpacked.
`-f'
`--basename'
Use only the last file name component of each input file name,
ignoring any prefix directories. This is sometimes useful when
building a shar from several directories, or another directory.
If a directory name is passed to `shar', the substructure of that
directory will be restored whether `-f' is specified or not.
File: sharutils.info, Node: unshar invocation, Next: Miscellaneous, Prev: shar invocation, Up: Top
Invoking the `unshar' program
*****************************
The format of the `unshar' command is:
unshar [ OPTION ] ... [ FILE ... ]
Each FILE is processed in turn, as a shell archive or a collection
of shell archives. If no files are given, then standard input is
processed instead.
Options:
`--version'
Print the version number of the program on standard output, then
immediately exits.
`--help'
Print an help summary on standard output, then immediately exits.
`-d DIRECTORY'
`--directory=DIRECTORY'
Change directory to DIRECTORY before unpacking any files.
`-c'
`--overwrite'
`-f'
`--force'
Passed as an option to the shar file. Many shell archive scripts
(including those produced by `shar' 3.40 and newer) accepts a `-c'
argument to indicate that existing files should be overwritten.
The option `-f' is provided for a more unique interface. Many
programs (such as `cp' and `mv') use this option to trigger the
very same action.
`-e'
`--exit-0'
This option exists mainly for people who collect many shell
archives into a single mail folder. With this option, `unshar'
isolates each different shell archive from the others which have
been put in the same file, unpacking each in turn, from the
beginning of the file towards its end. Its proper operation
relies on the fact that many shar files are terminated by a
`exit 0' at the beginning of a line.
Option `-e' is internally equivalent to `-E "exit 0"'.
`-E STRING'
`--split-at=STRING'
This option works like `-e', but it allows you to specify the
string that separates archives if `exit 0' isn't appropriate.
For example, noticing that most `.signatures' have a `--' on a
line right before them, one can sometimes use `--split-at=--' for
splitting shell archives which lack the `exit 0' line at end. The
signature will then be skipped altogether with the headers of the
following message.
File: sharutils.info, Node: Miscellaneous, Prev: unshar invocation, Up: Top
Miscellaneous considerations
****************************
Here is a place-holder for many considerations which do not fit
elsewhere, while not worth a section for themselves.
Be careful that the output file(s) are not included in the inputs or
`shar' may loop until the disk fills up. Be particularly careful when
a directory is passed to `shar' that the output files are not in that
directory (or a subdirectory of that directory).
When a directory is passed to `shar', it may be scanned more than
once, to conserve memory. Therefore, one should be careful to not
change the directory contents while `shar' is running.
No attempt is made to restore the protection and modification dates
for directories, even if this is done by default for files. Thus, if a
directory is given to `shar', the protection and modification dates of
corresponding unpacked directory may not match those of the original.
Use of the `-M' or `-B' options will slow down the archive process.
Use of the `-z' or `-Z' options may slow the archive process
considerably.
Let us conclude by a showing a few examples of `shar' usage:
shar *.c > cprog.shar
shar -Q *.[ch] > cprog.shar
shar -B -l28 -oarc.sh. *.arc
shar -f /lcl/src/u*.c > u.sh
The first shows how to make a shell archive out of all C program
sources. The second produces a shell archive with all `.c' and `.h'
files, which unpacks silently. The third gives a shell archive of all
uuencoded `.arc' files, into files `arc.sh.01' through to `arc.sh.NNN'.
The last example gives a shell archive which will use only the file
names at unpack time.
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