IZREADME_SMS (IZREADME.SMS): Info-ZIP for SMS/QDOS,   last revised: 15-Jun-1998===============================================================================[was "InfoZIP_SMSQDOS_ReadMe" in J. Hudson's original ports, ca. 08/1995]Info-ZIP Programs=================ZipUnZipUnZipSFXfUnZipIntroduction------------This archive is a result of frustrations with contemporary (August 95)versions of Zip and UnZip. While they use the same compressionalgorithms as the Info-ZIP programs, there the compatibility ends. Ifyou just use Zip/UnZip only on SMS/QDOS, then perhaps this is not aproblem (but I know for some users it still is); if you use Zip/UnZipto transport source code and data between diverse systems, then thedisregard for Info-ZIP standards is inconvenient, particularly thefact that directories are not supported and files are always storedunderscored.This release of Zip/UnZip offers:    o   zipfile/directory compatibility with all other supported        platforms    o   SMS/QDOS compatibility and back-compatible with earlier        versions.    o   Improved performance (Zip is typically 50% faster)    o   Command-line compatibility with Info-ZIP    o   Self-extracting archives (but not very elegantly)    o   Archives are marked as 'created by SMS/QDOS'.    o   Optional recursion into directories    o   Directory structure restored on unzip of Info-ZIP/PKZIP-        compatible archives.    o   Config'urable for listing and unpack formats (Info-ZIP (.) or        SMS/QDOS (_) and 'Press any key' timeouts. Override options        from command line.Info-ZIP Standards------------------This (rather long-winded and waffling) section discusses theconventions and standards used by Info-ZIP-compatible archivers and how"Info-ZIP for SMS/QDOS" achieves compatibility.Info-ZIP Zip/UnZip on all supported platforms (Unix, DOS, OS/2, NT,VAX/VMS, Amiga etc etc), works in a specific way. (Until now SMS/QDOSwas neither 'supported' nor Info-ZIP-compliant.)    a. The zipfile directory is in (/.) (Unix) format.    b. When zips are listed, it is in 'zipfile' (Unix) format.    c. When files are added, they are defined in native format.    d. When files are added, this is shown in 'zipfile' format.    e. When files are unpacked, this is done to native format, but       selection is done in 'zipfile' format.Basically, the listing and stored format of a file is that of thedestination.So, given a file structure at some arbitrary 'root' level.    Makefile    src (Dir)        afile.c        bfile.c        docs (Dir)             prog.txt    hdr (Dir)        cfile.h        dfile.hThen these would be in Unix (and Amiga) as     Makefile     src/afile.c     src/bfile.c     src/docs/prog.txt     hdr/cfile.h     hdr/dfile.hThis is also how the zipfile directory appears.And in DOS/OS2/NT    Makefile    src\afile.c    src\docs\prog.txt    hdr\cfile.h         .. etcAnd in VMS      (we SHOUT in VMS and have a silly file system)    MAKEFILE    [SRC]AFILE.C    [SRC.DOC]PROG.TXT    [HDR]CFILE.H        .. etc                        (OK VMS purist, [.SRC] etc. Only an example)And in SMS/QDOS (quiet again, but slightly ludicrous !)    Makefile    src_afile_c    src_doc_prog_txt    hdr_cfile_h         .. etcThe main problem regarding SMS/QDOS is not that of extensions - (afterall, only VMS and DOS _really_ have extensions; Unix, AmigaDOS, NT andOS/2 (and Win95) allow multiple '.' in.long.file.names.The SMS/QDOS problem is that '_' is both a legal file name characterand a directory separator. This creates the difficulties, asdirectories and files are somewhat different objects.It is the intention that these versions of SMS/QDOS Zip/UnZip willfollow the Info-ZIP rules, thus providing compatibility with the otherplatforms. It is possible to zip the file structure described above onSMS/QDOS and unpack it on VMS and get the VMS structure as shown in theexample (and vice-versa). [We only choose the most obtuse filesystems for the examples].In order to achieve this, SMS/QDOS names are mapped into Unix-styleones when the zipfile is created and un-mapped when it is unpacked.There is an option to unpack in 'zipfile' format (i.e. with '.' ratherthan '_'), but there will be no option to pack to all '_'. That wouldcontravene the standard.  However, a file        src_split_name_c        (which is src->split_name_c !)                                          src/split_name.c)where src is a hard directory, would be stored in the zip directory as      src/split_name.cIt does handle '_' with a little intelligence.The default UnZip option will be to translate '.' to '_'; this isbecause there are still many QDOS/Minerva users that cannot handle '.'without quotes, which is immensely inconvenient. For many SMS users'_' is also the most natural and convenient option. It also means thatSMS/QDOS <-> SMS/QDOS Zip - UnZip sequences are transparent.There will, however, be two ways around this in UnZip.      1. It is possible to Config the UnZip default to be '.'         translations (or not).      2.  The UnZip -Q1 option will toggle the default (Config'ed)          state.Examples:Given that we want/have     Makefile                   (Makefile)     src/afile.c                (src_afile_c)     src/bfile.c                (src_bfile_c)     src/docs/prog.txt          (src_docs_prog_txt)     hdr/cfile.h                (hdr_cfile_h)     hdr/dfile.h                (hdr_dfile_h)Then on SMS/QDOS we might have added the *.c files as     ex zip;'-r test *_c'(or VMS, just to do something different)    zip -r test [.src]*.cIn both cases the file lists as above (left).To unpack on SMS/QDOS (just the _c/.c files)   ex unzip;'test src/*.c'   (and VMS, unzip test src/*.c)i.e. in both cases using the 'zipfile' format. As a concession toSMS/QDOS, you could also have:   ex unzip;'test src_*_c'        but not unzip test [.src]*.c on VMS !!!!! Sorry, dinosaurs.Both SMS/QDOS commands unpack to     src_afile_c etc, where src_ is a hard sub-directory.(and the VMS example would unpack to [.src]afile.c, (or to src\afile.c onDOS/NT/OS2 etc).Options & SMS/QDOS Features---------------------------The options supported by Zip/UnZip are basically those documented inthe Info-ZIP documents and shown in on-line 'usage'. In particular, -rand -j work as intended.PLEASE NOTE: Previous SMS/QDOS zip/unzips have NOT followed theseconventions, for example -r was not implemented and -j was reversed.A number of -Q (SMS/QDOS-specific) options (not yet in the currentdocuments or usage screens) are implemented.The Zip 2.0.1 (and later) default is to add SMS/QDOS headers wherefile type = 1 (exe) or 2 (rel) or (type > 0 && != 255 and (filesize %64) != 0). Directories are included anyway, unless you zip -D.Where a header is added for an 'exe' file a '*' is displayed after thename in the zip display  (and '#' for 'rel' files).The -Q options for Zip are:    -Q1  Don't add headers for ANY files    -Q2  Add headers for all files    -Q4  Don't wait for interactive key press    (additive, so -Q5 => no headers, no wait, -Q6 all headers,     no wait etc)    (the default is exec/rel headers, 5 sec wait)Zip has rationalised the file header storage in zipfiles. Theprevious Zip used to store a QDOS header for each file. This was verywasteful, for example compressing a SMS/QDOS release of PGP in thisway came to 730Kb, too large for a DD disk. Changing the Zip programjust to add a header record for the single PGP exe and the zipfilesize went down to around 690Kb.And for UnZip    -Q1 Toggle unpack format status ('.' <-> '_')    -Q2 Toggle listing format    -Q4 Don't wait for key pressFiles Types-----------The history of QDOS suffers from incompatible featureimplementations. For example, Thor directories have file type 3, CSThave type 4 and Level 2 have type 255. Some software writers (bothamateur and otherwise) have used type 3 or 4 for other purposes(backward compatibility ?? who cares ??).In order to bypass problems cause by incompatible (inconsiderate ?)usage of file types, the file type denoting a directory is aConfig'urable item. The default is set to -1 (65535 in Config terms),which means "determine directory type from the file header of the rootdirectory". If this is appears unsuccessful on your system, the valuecan be Config'ed in the range 3-255.Zip assumes a file is a directory if:        ((type == CONFIGed_type) && (file_size % 64) == 0)If you are unfortunate enough have files of that pass this test butare not directories, then Zip will loop endless, as SMS/QDOS opens theroot directory again !!! (recursion: see recursion etc).I suggest you refrain from zipping such files and contact the softwaresupplier and point out the error of their ways.File Naming Issues------------------Zip will append a '_zip' suffix to the archive filename when thesupplied name (i.e. excluding device/directory parts) does notcontain a '_' or a '.'. This is broadly compatible with Info-ZIP,taking into account the '_' aberation.So        ex zip;'ram2_test ...'          >> ram2_test_zip        ex zip;'ram2_test.zip ...'      >> ram2_test.zip        ex zip;'ram2_test_rep ... '     >> ram2_test_rep        ex zip;'ram2_fdbbs.rep ... '    >> ram2_fdbbs.rep        ex zip;'ram2_test_rep.zip ...'  >> ram2_test_rep.zipThis implies that if a file ram2_test.zip exists, and you do:        ex zip;'ram2_test ...'Then a new file (test_zip) is created, rather than 'test.zip' beingupdated.