ALL ABOUT FILENAMES & EXTENSIONS



     .COM  =  Command file

     .EXE  =  Executable file

     .BAS  =  BASIC source file

     .ASM  =  Assembly source file

     .PAS  =  Pascal source file

     .ASC  =  Program source file in ASCII

     .TXT  =  Text file usually in ASCII

     .DOC  =  Documentation usually in ASCII

     .OBJ  =  Object file to be linked into a .EXE or .COM format

     .FIX  =  Fix to (usually) BASIC source

     .WKS  =  Lotus 1-2-3 worksheet

     .WRK  =  Lotus Symphony worksheet, also .WR1
     .VC   =  Visicalc worksheet

     .C    =  "C" Language program
     .SC   =  Supercalc worksheet

     .LBR  =  Library or group of related programs

     .ARC  =  File Archive Grouping - group of related programs



     You will need a program to split up the library into its individual

     programs.  Get LAR or the LU program on this board.

     (ie: LU.EXE - runs quite fast. To obtain help enter LU.)



     File extensions that have  a "Q" in the  middle such as .BQS, .EQE,

     .LQR,  .DQC,  etc.  have been "squeezed" with a rather  complicated

     compression routine to produce a new file which is usually smaller.

     The routine represents  frequently occurring characters  with fewer

     bits. You will need a unsqueeze program such as  " NUSQ.COM " to do

     the job.   Not all  unsqueeze programs around are  the same but you

     shouldn't have too many problems.  If you want to squeeze a program

     to send to me for example, use  "SQPC.COM".  Both of these programs

     can be found on this board. Often there are squeezed libraries such

     as .LQR so  usually you will "unsqueeze" it first  and split up the

     library, but there are a few exceptions.



                  ARC   ...     File Archive Utility



     ARC is used to create and maintain file archives.   An archive is a

     group of files collected  together into one file in such a way that

     the individual files may be recovered intact.



     ARC is different from other  archive and library  utilities in that

     it automatically compresses  the files being archived,  so that the

     resulting archive takes up a minimum amount of space.



     When ARC is used to add a  file to an archive it  analyzes the file

     to determine which of  four storage methods  result in the greatest

     savings.  These four methods are:



     1)  No compression; the file is stored intact.



     2)  Repeated-character compression;  repeated sequences of the same

         byte value are collapsed into a three-byte code sequence.



     3)  Huffman squeezing;  the file is compressed into variable length bit

         strings, similar to the method used by the SQ programs.



     4)  Lempel-Zev  compression;   the file is  stored  as a  series of

         twelve bit codes which  represent character strings,  and which

         are created "on the fly".



     Note that since one of the  four methods involves no compression at

     all,  the resulting  archive  entry will  never be larger  than the

     original file.







                               USING ARC

                               =========



     ARC is invoked with a command of the following format:



          ARC <x> <arcname> [<template> . . .]



     Where:



          <x> is an ARC  command letter (see below),  in either upper or

          lower case.



     <arcname> is the name of  the archive to act on, with or without an

     extension.   If no extension  is supplied,  then ".ARC" is assumed.

     The archive  name  may include  path and drive  specifiers,  as the

     archive itself may be anywhere you wish.



     <template>  is  one or more  file name templates.   The  "wildcard"

     characters "*" and "?" may be used.   A file name  template may NOT

     include a path or drive specifier,  as all  of the files must be in

     your current directory on your current disk.



     If ARC is invoked with no arguments  (by typing "ARC", and pressing

     "enter"), then a brief command summary is displayed.





                                ARC COMMANDS





     Following is a brief summary of the available ARC commands:



       a,u = add files to archive

       m   = move files to archive

       d   = delete files from archive

       x,e = extract files from archive

       r   = run files from archive

       p   = copy files from archive to stdout

       l   = list files in archive

       v   = verbose listing of files in archive

       t   = test archive integrity

       c   = convert entry to new packing method

       b   = retain backup copy of archive

       w   = suppress warning messages

       n   = suppress notes and comments



     I hope this has helped you and ifa you have any problems leave me a

     comment in the  "C)omments" section of the board.