zoo.man

汇编大全 中国矿业大学计算机学院 汇编实验5

     It is important to note that zoo's idea of the latest gen-
     eration of a file is not based upon searching the entire
     archive.  Instead, whenever zoo adds a file to an archive,
     it is marked as being the latest generation.  Thus, if the
     latest generation of a file is deleted, then no generation
     of that file is considered the latest any more.  This can be
     surprising to the user.  For example, if an archive already
     contains the file stdio.h:5 and a new copy is added, appear-
     ing in the archive listing as stdio.h:6, and then stdio.h:6
     is deleted, the remaining copy stdio.h:5 will no longer be
     considered to be the latest generation, and the file
     stdio.h:5, even if undeleted, will no longer appear in an
     archive listing unless generation 5 (or every generation) is
     specifically requested.  This behavior will likely be
     improved in future releases of zoo.

FILES
     xXXXXXX - temporary file used during packing
     archive_name.bak - backup of archive

SEE ALSO
     compress(1), fiz(1)

BUGS
     When files are being added to an archive on a non-MS-DOS
     system, it is possible for zoo to fail to detect a full disk
     and hence create an invalid archive.  This bug will be fixed
     in a future release.

     Files with generation counts that wrap around from 65535 to
     1 are not currently handled correctly.  If a file's genera-
     tion count reaches a value close to 65535, it should be
     manually set back down to a low number.  This may be easily
     done with a command such as gc-65000, which subtracts 65000
     from the generation count of each specified file.  This
     problem will be fixed in a future release.

     Although zoo on **IX systems preserves the lowest nine mode
     bits of regular files, it does not currently do the same for
     directories.

     Currently zoo's handling of the characters : and ; in
     filenames is not robust, because it interprets these to
     separate a filename from a generation number.  A quoting
     mechanism will eventually be implemented.

     Standard input cannot be archived nor can a created archive
     be sent to standard output.  Spurious error messages may
     appear if the filename of an archive is too long.

     Since zoo never archives any file with the same name as the
     archive or its backup (regardless of any path prefixes),
     care should be taken to make sure that a file to be archived
     does not coincidentally have the same name as the archive it
     is being added to.  It usually suffices to make sure that no
     file being archived is itself a zoo archive.  (Previous ver-
     sions of zoo sometimes tried to add an archive to itself.
     This bug now seems to be fixed.)

     Only regular files are archived; devices and empty direc-
     tories are not.  Support for archiving empty directories and
     for preserving directory attributes is planned for the near
     future.

     Early versions of MS-DOS have a bug that prevents "." from
     referring to the root directory;  this leads to anomalous
     results if the extraction of paths beginning with a dot is
     attempted.

     VAX/VMS destroys case information unless arguments are
     enclosed in double quotes.  For this reason if a command
     given to zoo on a VAX/VMS system includes any uppercase
     characters, it must be enclosed in double quotes.  Under
     VAX/VMS, zoo does not currently restore file timestamps;
     this will be fixed as soon as I figure out RMS extended
     attribute blocks, or DEC supplies a utime() function, which-
     ever occurs first.  Other VMS bugs, related to file struc-
     tures, can often be overcome by using the program bilf.c
     that is supplied with zoo.

     It is not currently possible to create a zoo archive con-
     taining all zoo archives that do not contain themselves.

DIAGNOSTICS
     Error messages are intended to be self-explanatory and are
     divided into three categories.  WARNINGS are intended to
     inform the user of an unusual situation, such as a CRC error
     during extraction, or -freshening of an archive containing a
     file newer than one specified on the command line.  ERRORS
     are fatal to one file, but execution continues with the next
     file if any.  FATAL errors cause execution to be aborted.
     The occurrence of any of these causes an exit status of 1.
     Normal termination without any errors gives an exit status
     of 0.  (Under VAX/VMS, however, to avoid an annoying mes-
     sage, zoo always exits with an error code of 1.)

COMPATIBILITY
     All versions of zoo on all systems are required to create
     archives that can be extracted and listed with all versions
     of zoo on all systems, regardless of filename and directory
     syntax or archive structure;  furthermore, any version of
     zoo must be able to fully manipulate all archives created by
     all lower-numbered versions of zoo on all systems.  So far
     as I can tell, this upward compatibility (all manipulations)
     and downward compatiblity (ability to extract and list) is
     maintained by zoo versions up to 2.01.  Version 2.1 adds the
     incompatibility that if high-performance compression is
     used, earlier versions cannot extract files compressed with
     version 2.1.  This is the only incompatibility that is
     permissible.  You are forbidden, with the force of copyright
     law, to create from the zoo source code any derivative work
     that violates this compatibility goal, whether knowingly or
     through negligence.  If any violation of this compatibility
     goal is observed, this should be considered a serious prob-
     lem and reported to me.

CHANGES
     Here is a list of changes occurring from version 1.50 to
     version 2.01.  In parentheses is given the version in which
     each change occurred.

     -    (1.71) New modifiers to the list commands permit
          optional suppression of header and trailer information,
          inclusion of directory names in columnized listings,
          and fast one-column listings.

     -    (1.71) Timezones are handled.

     -    (1.71) A bug was fixed that had made it impossible to
          individually update comments for a file whose name did
          not correspond to MS-DOS format.

     -    (1.71) A change was made that now permits use of the
          shared library on the **IX PC.

     -    (1.71) VAX/VMS is now supported reasonably well.

     -    (2.00) A comment may now be attached to the archive
          itself.

     -    (2.00) The OO option allows forced overwriting of
          read-only files.

     -    (2.00) Zoo will no longer extract a file if a newer
          copy already exists on disk;  the S option will over-
          ride this.

     -    (2.00) File attributes are preserved for **IX systems.

     -    (2.00) Multiple generations of the same file are sup-
          ported.

     -    (2.00) Zoo will now act as a compression or decompres-
          sion filter on a stream of data and will use a CRC
          value to check the integrity of a data stream that is
          uncompressed.

     -    (2.00) A bug was fixed that caused removal of a direc-
          tory link if files were moved to an archive by the
          superuser on a **IX system.

     -    (2.00) The data recovery modifier @ was greatly
          enhanced.  Self-extracting archives created for MS-DOS
          systems can now be extracted by zoo on any system with
          help from fiz(1).

     -    (2.01) A bug was fixed that had caused the first gen-
          eration of a file to sometimes unexpectedly show up in
          archive listings.

     -    (2.01) A bug was fixed that had caused the MS-DOS ver-
          sion to silently skip files that could not be extracted
          because of insufficient disk space.

     -    (2.01) A bug was fixed that had sometimes made it
          impossible to selectively extract a file by specifying
          its name, even though all files could be extracted from
          the archive by not specifying any filenames.  This
          occurred when a file had been archived on a longer-
          filename system (e.g. AmigaDOS) and extraction was
          attempted on a shorter-filename system (e.g. MS-DOS).

     -    (2.01) A change was made that will make zoo preserve
          the mode (file protection) of a zoo archive when it is
          packed.  This is effective only if zoo is compiled to
          preserve and restore file attributes.  Currently this
          is so only for **IX systems.

     -    (2.01) A bug was fixed that had caused an update of an
          archive to not always add all newer files.

     -    (2.01) Blanks around equal signs in commands given to
          "make" were removed from the mk* scripts for better
          compatiblity with more **IX implementations including
          Sun's.

     -    (2.1) Compression is now greatly improved if the "h"
          option is used.

     -    (2.1) The default behavior is to preserve full path-
          names during extraction.

     -    (2.1) On some systems, extraction of files using the
          older (default) compression method is greatly speeded
          up.

     -    (2.1) Extended multiscreen help is available.

     -    (2.1) Memory allocation is improved, so that the MS-DOS
          version will not prematurely abort when updating a
          large archive.

     -    (2.1) The VAX/VMS version preserves file timestamps
          during extraction.

     -    (2.1) The default archive-wide generation limit, when
          generations are enabled, is 3.

FUTURE DIRECTIONS
     A revised version of zoo is in the works that will be able
     to write newly-created archives to standard output and will
     support multivolume archives.  It will be upward and down-
     ward compatible with this version of zoo.

ACKNOWLEDGEMENTS
     The zoo archiver was initially developed using Microsoft C
     3.0 on a PC clone manufactured by Toshiba of Japan and
     almost sold by Xerox.  Availability of the following systems
     was helpful in achieving portability: Paul Homchick's Compaq
     running Microport System V/AT;  The Eskimo BBS somewhere in
     Oregon running Xenix/68000; Greg Laskin's system 'gryphon'
     which is an Intel 310 running Xenix/286;  Ball State
     University's AT&T 3B2/300, UNIX PC, and VAX-11/785 (4.3BSD
     and VAX/VMS) systems.  In addition J. Brian Waters provided
     feedback to help me make the code compilable on his Amiga
     using Manx/Aztec C.  The executable version 2.0 for MS-DOS
     is currently compiled with Borland's Turbo C++ 1.0.

     Thanks are due to the following people and many others too
     numerous to mention.

     J. Brian Waters <[e-mail]>, who has worked
     diligently to port zoo to AmigaDOS, created Amiga-specific
     code, and continues keeping it updated.

     Paul Homchick <rutgers!cgh!paul>, who provided numerous
     detailed reports about some nasty bugs.

     Bill Davidsen <[e-mail]>, who provided
     numerous improvements to this manual, contributed mul-
     tiscreen help, and provided many useful bug reports, bug
     fixes, code improvements, and suggestions.

     Mark Alexander <amdahl!drivax!alexande>, who provided me
     with some bug fixes.

     Haruhiko Okumura, who wrote the ar archiver and some excel-
     lent compression code, which I adapted for use in zoo.

     Randal L. Barnes <[e-mail]>, who (with
     Randy Magnuson) wrote the code to support the preservation
     of file timestamps under VAX/VMS.

     Raymond D. Gardner, who contributed replacement uncompres-
     sion code that on some systems is twice as fast as the
     original.

     Greg Yachuk and Andre Van Dalen, who independently modified
     MS-DOS zoo to support multivolume archives.  (This support
     is not yet in this official release.)

AUTHOR
     Rahul Dhesi