Commodore PC 20 - Page 168

130 MS-DOS User's Reference
The Backup switches
You can specify the following switches with backup:
Is Backs up subdirectories also.
1m
la
Id
It
IL
Backs up only those files that have changed since the
last backup.
Adds
the files to be backed up to those already on the
backup disk. It does not erase old files on the backup
disk.
Backs
up only those files that you last modified on or
after date.
Backs up only those files that you last modified at or
after a certain time.
Makes a backup log entry in the specified file. If you
do not specify a filename, backup places a file called
backup. log in the root directory of the disk that con-
tains
the files being backed up. The first line of the
entry in the file contains [date time) where date and
time are the backup dates and times. Each subsequent
line in the entry corresponds to a backed up file. These
lines each consist of a filename and the number of the
disk that contains the file. You can use this information
when you need to restore a particular file from a
floppy disk,
but you must specify which disk to restore
so that backup does not have to search for files. If the
backup log file already exists, backup appends the
current entry to the file.
Backup displays the name of each file as it is backed up. You
should label and number each backup disk consecutively to help
you restore the files properly with the restore command.
If you are sharing files, you can back up only the files that you
have access to.
Note You
should not use the backup command if the drive you
are backing up has been assigned, joined, or substituted with the
assign, join, or subst command. If you do, you may not be able
to restore the files with the restore command.
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