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           SORTS - A Multi-Key Record Sorting Utility

                           Version 1.4

             by William C. Parke (c) Copyright 1986
                             for CHUG
              the Capital Heath/Zenith Users' Group

INTRODUCTION

SORTS is  a record  sorting program  for MS-DOS computer systems.
It will  sort records  from files  larger than  64K in size, with
tens of  thousands of  records (depending  on the  memory in  the
computer), sorting  on an arbitrary set of key fields selected in
any order.   Record  lengths can  be variable,  with  up  to  255
characters in  each.   The sorting  keys can  be from  one to 255
characters long,  taken from columns in the records in any order.
Often used  key-column orders  can  be  saved  within  SORTS  and
recalled by  a single  letter name.  Any part or parts of the key
can be selected for reverse order sorting.

The advantages of SORTS are the following:

1.   Speed:   SORTS was  written  in  assembly  language  and  it
performs its  sorts in  memory, making  its operations  very fast
relative to many other sorting programs.

2.   Capacity:   SORTS can handle files with approximately 30,000
records and up to a 7.5 Megabyte file.

3.   Flexibility:  SORTS can perform multiple field sorting based
on a selection of columns making up a sorting key.  Each selected
column can be sorted in reverse order or normal ASCII order.

4.   Ease of Use:  SORTS can save up to 8 set of columns used for
a sorting key.  This setting can be recalled by a single letter.

PURPOSE OF SORTS:

SORTS is  use to  arrange records  in a  file  in  numerical  and
alphabetical order,  starting at  any position in the record, and
using an  arbitrary set  of columns  to perform  the ordering.  A
record  is  any  set  of  characters  terminated  by  a  carriage
return/line feed.  SORTS does not require the records be of fixed
length, but they must not exceed 255 characters per record.

SORTS is  handy for  sorting  disk  catalogs,  name  directories,
numerical data,  address lists, etc. based on selected key fields
within the  records.   It is  probably  the  fastest  multi-field
sorting utility  available.   It gains  speed by using all of the
available free RAM (up to the 640K limit on MS-DOS machines).  It
will not operate on files with more than about 30,000 records.

INVOKING SORTS:

The command syntax for SORTS is:

   SORTS oldfile newfile [/t][/sx][/c1-c2,c3,...]

where
        oldfile is the name of the file which stores the unsorted
              records (with optional path name prefix),
        newfile is  the name  of the  file you  wish to  use  for
              storing  the   sorted  records  (newfile  may  also
              contain a path name prefix);

        t  is an optional toggle:
          t= C   will make SORTS ignore the case of letters while
              sorting,

        s is an optional selection:
          s= Sx  indicates that the column order which follows is
              to be saved and given the name 'x',
          s= Ux     indicates that  the previously  saved  column
              order 'x' is to be used for the present sort;

        c1-c2,c3,... are  optional column  numbers, starting at 1
              for the  first column in the record. The pair c1-c2
              makes the columns from c1 to c2 (inclusive) part of
              the sorting  key.   The single  value like c3 above
              adds the  single column  at c3  to the  key.  If no
              columns are  given, a  default of  columns 1-12  is
              assumed.
        If an  R appears  in front  of any pair of column numbers
              (or in  front of  a singular  column number),  that
              column range  (or single  column) will be sorted in
              reverse ASCII order.

EXAMPLES:

1. Getting a reminder of SORTS' syntax and stored fields:

        SORTS

will give a brief help screen indicating the syntax for SORTS and
will show  the current  names and  values of  the  stored  column
orders to  make key  fields.   This same  help  screen  is  shown
whenever a command line syntax error occurs. The initial settings
for the  stored column orders  match  the  columns  used  in  the
companion program  CATS,  used to catalog a large number of files
on multiple disks.

2. Sorting by default:

        SORTS NAM.REC NAME.REC

will sort  the records  in the  file NAM.REC,  using the  default
first 12  columns of  each record  as a  key field.   The  sorted
records will be written to NAME.REC.

3. Sorting with new key field:

        SORTS FOO.BAR FOOD.BAR/8-10,r1-3,40,43,50-60

will sort  the records  in the file FOO.BAR, using a key based on
the columns:

   8,9,10,1,2,3,40,43,50,51,52,53,54,55,56,57,58,59,60

in that  order, in  FOO.BAR.   This operation will produce a file
FOOD.BAR with  all 'A's  in column  8 before 'B's, etc.  For each
record with  a given  sequence in  columns 8,  9, and 10, records
with a  'Z' in  column 1  will come before those with a 'Y', etc.
Specifying multiple  columns  in  this  way  has  the  effect  of
performing a  multiple  number  of  sorts  on  each  key  subset,
preserving the previously sorted fields.

4.  Defining a new key field column order:

        SORTS /Sa/r14-15,1-8,10

will save  the column  order settings r14-15,1-8,10 into a buffer
in SORTS  with the  name 'a'.   (The 'a' can be in upper or lower
case.)   This setting can be reviewed with the command SORTS with
no command tail as in the first example above.

5.  Defining and operating with a new key field column order:

        SORTS MAY.DIG MAYBE.DIG/Sm/20-24,1-8

will save  the key  columns 20-24,1-8 with name 'm' and then sort
the records in MAY.DIG according to this key.

6.  Ignoring case while sorting:

        SORTS \CATS\CATS.DIR CATST.DIR/C/UT

will sort  the file  CATS.DIR in the directory called CATS, using
the previously  set column order named 't', and ignoring the case
of the characters.

7.  Erasing a previously defined column order:

        SORTS /Sa/0

will erase  the column  order labeled 'a' from the storage buffer
in SORTS.   This  will make  space for  a new column order with a
different label.

SORTS OPERATION

After the  program begins,  SORTS will show the key field columns
it will use for the sorting.  It then calculates and displays the
total number  of records which could be sorted with the given key
field length,  assuming resident  programs are  not  loaded  into
memory.   SORTS follows by showing how many records can be sorted
with the  current free  memory.  Next, the output file is opened.
If it  already exits,  you will be asked if you wish to overwrite
it.   Then, the  key fields  of the file records to be sorted are
read into memory.  SORTS will display the total number of records
it has  found, and check if enough memory is available to perform
the sort.   If so, the sorting is done in memory. The file is re-
read in record sorted form to be written to the output file.

SORTING CONSIDERATIONS

Key field  lengths from 1 to 12 will permit the largest number of
records to be sorted.  With a total key field length of 13 to 28,
only half  that number  can be  sorted.   When picking columns by
examining sample  records to be sorted, try to keep the total key
field length  in the  1-12 range.   If  this is not possible, you
should then  try to  use less  than 29 columns for the key field.
For example, if a record had the following format (column numbers
are given above record):

         1         2         3         4         5
12345678901234567890123456789012345678901234567890
FOOBAR   EXE     89984 83/11-30 01:23 DISK 000001\.........

then sorting  on the date and time field (24-37) can be done with
the key  columns set  to either  24-37, or  24-25,27-28,30-31,33-
34,36-37.   This second  choice eliminates the '/', '-', and ' ',
and ':'  characters which are repeated in every record and do not
affect a record sort anyway.  Instead of (24-37), which has a key
width of  14, the segmented set has a width of only 10, leaving 2
more columns  available to make a 12 or less character key.  Note
that SORTS starts column numbers at 1 rather than 0.

For some  purposes, a  restricted sub-key  field produces  a more
interesting sorted  file than a wider field.  With records in the
format of the above example, taking the 'year' field (columns 24-
25) rather  than the  full date (columns 24-31) as the first part
of a  column order,  such as  24-25,1-12, produces  a sorted file
with  all   records  in   one  year  grouped  together  and  then
alphabetized by the names in the columns 1-12..

SORTS ERROR MESSAGES

Column order "x" in use.  Overwrite it ?
        The selection  /Sx was  made for  a column  order already
        defined.

Column order "x" not found.
        The selection  /Ux was  made for  a column  order not yet
        defined.

Column syntax error.
        The format  of the  /c1-c2,c3,... column  order  was  not
        correct.  See the examples above for the correct syntax.

Erase column order "x" ?
        A request  to overwrite  a previously define column order
        was made with the /Sx selection.

Error opening [filename]
        The input file specified was not found.

Error Reading file
        An error occurred in attempting to read the input file.

Error Writing sorted file
        An error occurred in attempting to write the output file.

Insufficient memory.
        SORTS did  not find enough free RAM for its required file
        buffers.

Invalid DOS Version.
        SORTS requires MS-DOS 2.1 or above.

Maximum 16 column pairs exceeded.
        Too many column pairs were given on the command line.

No free new column space.
        All of  the column order settings have been defined.  Use
        the /Sx/0 command to erase one of them.

Output file already exits. Overwrite it ?
        Overwriting the  output file  will destroy  any  previous
        data in that file.  The input file is unaffected.

Output file cannot be input file.
        The output  file was  given the  same name  as the  input
        file.  SORTS cannot operate on just one file.

S selection requires column order.
        The /Sx  selection must  be followed  by a  column  order
        definition: /c1-c2,c3,...

SORTS.COM not found.
        If a  /Sx selection is to save a column order, SORTS must
        be able to find itself on the disk.

U selection takes no column order.
        The /Ux  selection uses  a previously  defined and  saved
        column order  definition.   No /c1-c2,c3... should follow
        this selection.


Acknowledgement:

     This program was inspired by a sorting utility by Vernon Buerg.
Jerome Horwitz  and  Douglas Clark  in  CHUG  gave suggestions  and
encouragement.


Copyright Status:

The author retains all legal Copyrights to the program SORTS Version 1.4.
However, he grants individuals licence to use this program, and permits
non-profit and non-commercial distribution of the program.

Please send comments to:

        William C. Parke
        1820 S Street NW
        Washington, D.C. 20009