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NAME
AVLSort - Sort a file.
SYNOPSIS
AVLSort From To COLSTART/k WIDTH/k CASE/s REVERSE/s
DESCRIPTION
AVLSort was written to remedy several defects of the ARP Sort
command. AVLSort places each line of text in an AVL tree,
which has reasonable worst-case performance, even for large
files. I have not made speed comparisons with AmigaDos Sort
or with ARP Sort.
This program can handle large files, up to available memory.
There is no arbitrary limit on the number of lines in the file
(I have seen a report that ARP Sort is limited to 32767 lines).
The order of otherwise identical lines does not change in the
output file. This can happen in ARP Sort when using the
COLSTART and WIDTH switches.
If you omit the From argument from Sort, it reads from its
standard input, which allows it to be used in pipelines.
OPTIONS
COLSTART n
This takes a numeric argument which gives the starting
column for the sort. All entries to the left of this
column will not be considered in the final arrangement.
WIDTH n
This takes a numeric argument, which gives the width
for the sort. You can use this to specify a 'window'
for Sort to work on. For example, using a WIDTH of 4
will arrange a file based on the first 4 characters of
each line. If you also use COLSTART, then the first 4
characters starting at that column will be the ones on
which the sort is based.
CASE
The CASE switch will use a case-sensitive match, rather
than the default case-insensitive match.
REVERSE
The REVERSE switch will cause the sorted file to be
printed in reverse order. This switch is not part
of the AmigaDos or ARP Sort commands.
EXAMPLE
list >listfile
avlsort listfile colstart 41
or using pipes: list | avlsort colstart 41
This gives a listing of all files sorted by time (i.e., from
the earliest to the latest).
BUGS
File size is limited by available memory.
SEE ALSO
ARP Sort
CREDITS
The AVL tree package was written by Mark E. Mallett of Zinn
Computer Company, copyright 1988.
The startup code is by Sebastiano Vigna, based on previous
work by Scott Ballantine and John Toebes.
Much of this document (AVLSORT.DOC) was lifted from the ARP
documentation for Sort.