unzoo.c                     Tools                        Martin Schoenert

@(#)$Id: unzoo.c,v 4.4 2000/05/29 08:56:57 sal Exp $

This file is in the Public Domain.

SYNTAX

'unzoo'
'unzoo [-l] [-v] <archive>[.zoo] [<file>..]'
'unzoo -x [-abnpo] <archive>[.zoo] [<file>..]'

DESCRIPTION

'unzoo' is  a zoo  archive extractor.   A zoo archive   is  a  file  that
contains several files, called its members, usually in compressed form to
save space.  'unzoo' can list all or  selected members or  extract all or
selected members, i.e.,  uncompress them and write   them  to files.   It
cannot add new members or  delete  members.  For this   you need the  zoo
archiver, called 'zoo', written by Rahul Dhesi.

If you call 'unzoo'  with no arguments, it will  first print a summary of
the commands and  then prompt for  command lines interactively, until you
enter an empty line.  This is useful  on systems  that do not support the
notion of command line arguments such as the Macintosh.

If you call  'unzoo' with the  '-l' option,  it lists the  members in the
archive <archive>.   For each member 'unzoo'   prints  the size  that the
extracted file  would  have, the  compression factor,  the  size that the
member occupies in the archive (not  counting  the  space needed to store
the attributes such as the path name of the file), the date and time when
the files were last modified, and finally  the path name itself.  Finally
'unzoo' prints a grand total for the  file sizes, the compression factor,
and the member sizes.

The '-v' suboption causes 'unzoo' to append to each path name,  separated
by a ';', the generation number of the member,  where higher numbers mean
later generations.  Members for which generations are disabled are listed
with  ';0'.  Also 'unzoo'   will print the  comments associated  with the
archive itself or the members, preceeded by the string '# '.

If you call 'unzoo' with the '-x' option,  it extracts the  members  from
the archive <archive>.  Members are  stored with a  full path name in the
archive and if the operating system supports this, they will be extracted
into   appropriate subdirectories,   which will   be  created on  demand.
The members are usually  extracted as binary files,  with no translation.
However, if a member has a  comment that starts with the string '!TEXT!',
it is  extracted as a  text file, i.e.,  it will be  translated from  the
universal text file format (with <lf> as line separator as under UNIX) to
the local text file format (e.g., with <cr>/<lf> as separator under DOS).
If the archive  itself has a  comment that starts with  '!TEXT!' then all
members will be extracted as text files, even those that have no comment.
For each member the name is printed followed by  '-- extracted as binary'
or '-- extracted as text' when the member has been completely extracted.

The '-a' suboption causes  'unzoo' to extract all members  as text files,
even if they have no comment starting with  '!TEXT!'.

The '-b' suboption causes 'unzoo' to extract all members as binary files,
even if they have a comment starting with  '!TEXT!'.

The '-n' suboption causes 'unzoo' to suppress writing the files.  You use
this suboption  to test the integrity  of the archive  without extracting
the members.  For each member the name is printed followed by '-- tested'
if the member is intact or by '-- error, CRC failed' if it is not.

The '-p' suboption causes 'unzoo' to print the files to stdout instead of
writing them to files.

The '-o'  suboption causes 'unzoo'   to overwrite existing  files without
asking  you for confirmation.   The  default is  to ask for  confirmation
'<file> exists, overwrite it? (Yes/No/All/Ren)'.   To this you can answer
with 'y' to overwrite the  file, 'n' to skip  extraction of the file, 'a'
to overwrite this and all following files, or 'r' to enter a new name for
the file.  'unzoo' will never overwrite existing read-only files.

The '-j <prefix>' suboption causes 'unzoo' to prepend the string <prefix>
to  all path names for  the members  before  they  are extracted.  So for
example if an archive contains absolute  path names under  UNIX,  '-j ./'
can be used to convert them to relative pathnames.   This option  is also
useful  on  the Macintosh where   you start 'unzoo' by clicking,  because
then the current directory will be the one where 'unzoo' is,  not the one
where the  archive is.   Note  that the  directory  <prefix> must  exist,
'unzoo' will not create it on demand.

If no  <files>  argument is given all members  are  listed or  extracted.
If  one or  more <files>  arguments are given,  only members whose  names
match at least one of  the  <files> patterns  are  listed  or  extracted.
<files> can  contain the wildcard   '?', which  matches any character  in
names, and '*', which  matches any number  of characters  in names.  When
you pass the <files> arguments on the command  line you will usually have
to quote them to keep the shell from trying to expand them.

Usually 'unzoo' will  only list or extract the  latest generation of each
member.  But if you append ';<nr>' to a path  name pattern the generation
with the number <nr> is listed or extracted.  <nr> itself can contain the
wildcard characters '?' and '*', so appending ';*' to a path name pattern
causes all generations to be listed or extracted.


COMPATIBILITY

'unzoo'  is based heavily on the 'booz' archive extractor by Rahul Dhesi.
I basically stuffed everything in one file (so  no 'Makefile' is needed),
cleaned it up (so that it is now more portable and  a little bit faster),
and added the  support for  long file names,  directories,  and comments.

'unzoo' differs in some details from  'booz' and the zoo archiver  'zoo'.

'unzoo' can  only list  and extract members   from archives, like 'booz'.
'zoo' can also add members, delete members, etc.

'unzoo' can extract members as text files, converting from universal text
format to the local text format,  if the '-a' option is given or the '-b'
option is not given and the  member has a comment starting with '!TEXT!'.
So in the absence of the '-a' option and comments starting with '!TEXT!',
'unzoo' behaves like  'zoo' and 'booz',  which always extract as  binary.
But  'unzoo' can  correctly extract  text files from  archives that  were
created under UNIX (or other systems using the universal text format) and
extended with '!TEXT!' comments on systems such as DOS, VMS, Macintosh.

'unzoo' can handle  long names, which it converts  in  a system dependent
manner to local  names, like  'zoo'  (this may not   be available on  all
systems).  'booz' always uses the short DOS format names.

'unzoo' extracts  members  into  subdirectories, which  it  automatically
creates, like 'zoo' (this  may not be available on  all systems).  'booz'
always extracts all members into the current directory.

'unzoo'  can handle comments and generations in the  archive, like 'zoo'.
'booz' ignores all comments and generations.

'unzoo' cannot handle  members compressed with  the old method, only with
the new  high method or  not compressed  at all.   'zoo' and  'booz' also
handle members compress with the old method.  This shall be fixed soon.

'unzoo' can handle archives in  binary format under  VMS, i.e., it is not
necessary to convert  them to stream linefeed  format  with 'bilf' first.
'zoo' and 'booz' require this conversion.

'unzoo' is somewhat faster than 'zoo' and 'booz'.

'unzoo' should be much easier to port than both 'zoo' and 'booz'.

ACKNOWLEDGMENTS

Rahul Dhesi  wrote the  'zoo' archiver and the  'booz' archive extractor.
Haruhiko Okumura  wrote the  LZH code (originally for his 'ar' archiver).
David Schwaderer provided the CRC-16 calculation in PC Tech Journal 4/85.
Jeff Damens  wrote the name match code in 'booz' (originally for Kermit).
Harald Boegeholz  ported 'unzoo' to OS/2 with the emx development system.
Dave Bayer ported 'unzoo' to the Macintosh,  including Macbinary support.