BACKUP and RESTORE

Usage and messages

Due to the different versions of BACKUP and RESTORE in the different DOS versions, there are a lot of differences in the usage of the programs too.

As FreeDOS basically claims compatibility to MS-DOS 3.3, the FreeDOS BACKUP and RESTORE programs default to the usage of this MS-DOS version. As far as compatibility for different versions are implemented, a few additional switches and options are introduced.

Additional switches
 

 /?, /h show short usage/help message on the screen

The /?  is a requirement of FreeDOS, the /h is added for convenience. All other options given in combination with these switches are ignored

 /v[version] define the version of compatibility

As far as compatibility for different DOS versions is implemented, the /v switch can force the programs to behave accordingly.
32 or 3.2 The program uses data format and options of the BACKUP/RESTORE command of MS-DOS 3.2x and earlier
33 or 3.3 The program uses data format and options of the BACKUP/RESTORE of MS-DOS 3.3 to 5.0x
This is the default for both programs

So far, this switch is only requiered for the BACKUP program as the RESTORE program is able to determine the data format on it's own.

BACKUP

Back up one or more files from one disk onto another.

Syntax
backup <source> <destination-drive:> [/s] [/m] [/a] [/f[:size]] [/d:date] [/t:time] [/l[:[drive:][path]logfile]] [/p] [/{?,h}]

Parameters

source Specifies the location of the files you want to back up. Source can consist of a drive letter and a colon, a directory name, a filename or a combination.
destination-drive: Specifies the drive that contains the disk on which you want to store any backup files. The backup files are stored accordingly to the chosen compatibility mode (default is MS-DOS 3.3+)
 
Switches
/s  Backup all files of all subdirectories recursed into
/m Back up only files that have been changed since the last backup (that means all files where the Archive attribute is set) and turns off the archive attribute of the original file.
/a Add backup files to an existing backup disk without deleting existing files
/f[:size] Format the destination drive. If no size is given, the default for this drive is selected. 
Not implemented yet!
/d:date Backup all matching files changed on or after the given date
Not implemented yet!
/t:time Backup all matching files changed at or after the given time
Not implemented yet!
/l[:[drive:][path]logfile] Write the filesname of all backed up files and all error messages to a logfile.
Not implemented yet!
/p Not implemented yet!
/{?,h} This is a FreeDOS specific extension to show a help screen with the usage explanations.

Return codes/Errorlevels
The BACKUP command sets the ERRORLEVEL (return code) as follows:
0
Normal completion
1
No files were found to backup
2
Some files not backed up due to sharing conflicts
3
Terminated by user (Ctrl-Break or ESC)
4
Terminated due to error

Notes
- The BACKUP program allows only to do backups from a fixed disk to a diskette (removable disk). Other combinations will only be implemented if there are enough resonable requests for it.
- The BACKUP program doesn't do a format of the destination diskettes (yet).
Examples

 

RESTORE

Restore files that have been backed up by the BACKUP command.

Syntax
restore <drive1:> <drive2:>[path[filename]] [/s] [/p] [/b:date] [/a:date] [/e:time] [/l:time][/m] [/n] [/d]
Parameters
drive1: The drive that contains the backed-up files
drive2: The drive to which the backed-up files are going to be restored
path The directory to which the backed-up files are going to be restored. In MS-DOS you had to specify the same directory form which the files were backed-up. The FreeDOS restore program allows to specify any directory as the base for the to be restored directory structure.
filename The names of the files that are going to be restored

Switches
/s Restore all subdirectories
/p Prompt for permission to restore files that are marked as read-only or that have changed since the last backup (archive bit set)
/b:date Restore only those files modified on or before the given date.

The following switches are only valid for backup files with the data format of the DOS versions 3.3x to 5.0x
/a:date Restore only those files modified on or after the given date.
Note: As country specific settings are not implemented yet, the format for the date has to be given as YYYY-MM-DD. This is Y2K safe and the most universal format anyway.
/e:time Restore only those files modified at or earlier than the given time
/l:time Restore only those files modified at or later than the given time
Note: the time has to be given in 24h format. A check for the american 12h format has not (yet) be implemented
/m Restore only those files modified since the last backup (archive bit set)
/n Restore only those files that donít exist on the destination drive
/d Display those files that match the files specified for backup without actually restoring any files
Note: even though no files are actually restored, you have to specify drive2
/{?,h} This is a FreeDOS specific extension to show a help screen with the usage explanations.

Return codes/Errorlevels
The RESTORE command sets the ERRORLEVEL (return code) as follows:
0
Normal completion
1
No files were found to restore
2
Some files not restored due to sharing conflicts
3
Terminated by user (Ctrl-Break or ESC)
4
Terminated due to error

Notes
- To do a better job on restoring incomplete backup sets, the /d option uses a different format for the output list of files. It will show the sequence number of the disk (in case the disks are not marked properly) and it will also show special notes about split files at the beginning or the end of the disk.
In case of the restore of an incomplete backup set, this way the user can make a decision to restore partial files before the actual restore procedure.

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Examples