ZOO HISTORY 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 compatiblity (all manipulations) and downward compatiblity (ability to extract and list) is maintained by zoo version 2.0. 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-i.e., if you are able to use an implementation of zoo to create an archive that some implementation of zoo on any system cannot extract-this should be considered a serious problem and reported to me. CHANGES Zoo version 1.5 was posted to Usenet in mid-1987. Later, I distributed version 1.71 via anonymous UUCP and disks, but I did not widely distribute it by other means such as online information services or bulletin boards, because changes from 1.5 to 1.71 were minor. Although 1.5 was distributed for MSDOS in binary form, 1.71 was not. The Amiga version of 1.71 has just been released as this documentation is written. The current version 2.0 is a significant enhancement from 1.5, with many new features and improvements. Here is a list. In parentheses is given the version in which each feature was introduced. - (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. - (2.0) A comment may now be attached to the archive itself. - (2.0) The OO option allows forced overwriting of read- only files. - (2.0) Zoo will no longer extract a file if a newer copy already exists on disk; the S option will override this. - (2.0) File attributes are preserved for **IX systems. - (2.0) Multiple generations of the same file are sup- ported. - (2.0) 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. - (2.0) 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. - (2.0) 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). 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 also automatically perform end-of-line conversion for text files moved between dissimilar systems. It will be upward and downward compatible with existing versions 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 *T&T 3B2/300, **IX PC, and VAX-11/785 (4.3BSD) systems. In addition J. Brian Waters provided feedback to help me make the code compilable on his Amiga using Manx/Aztec C. More recently, actual development, as opposed to portability testing, has been done exclusively on my own AT from PC's Limited running Microport System V/AT. The executable version 2.0 for MS-DOS is currently compiled with Borland's Turbo C 1.0. Special thanks are due to: J. Brian Waters , who has worked diligently to port zoo to AmigaDOS, created Amiga-specific code, and continues keeping it updated. Paul Homchick , who provided numerous detailed reports about some nasty bugs. Bill Davidsen , who fixed zoo's handling of daylight savings time, provided changes to make this manual format correctly with troff, and provided many useful bug reports and suggestions. Mark Alexander , who provided me with some bug fixes, and also some portability modifications and speed optimizations that are due to be incorporated into the next release. AUTHOR Rahul Dhesi Feb 7, 1988