$kept-versions - Number of backups to be kept
$kept-versions integer; Default is 0
0 <= integer <= n
$kept-versions allows the user to specify the number of backup versions that are required for each file. For file "XXXX", each backup version is renamed to "XXXX.~?~", where ? is the backup number. If $kept-versions is set to 0 this feature is disabled and the default single backup file is created.
The most recent backup will always be .~0~ and the last version will be .~n~ where n is $kept-versions - 1. when the file is next saved the .~0~ backup file is moved to .~1~, .~1~ to .~2~ etc, backup .~n~ is removed. Evidently if $kept-versions it set to a large number this can effect performance.
$kept-versions may only be used when DOS file name restrictions are not enabled. This means that some systems (such as DOS) cannot use this functionality, see $system(5) for more information. Backup files are only created when buffer mode backup(2m) is enabled.
This feature is not supported when writing ftp files, a single backup file is created when backup files are enabled.
Copyright (c) 1998-2006 JASSPA
Last Modified: 2002/01/11
Generated On: 2006/10/07