In
computing,
recover is a primitive
file system
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...
error recovery utility included in
MS-DOS /
IBM PC DOS versions prior to DOS 6.0 and a number of other
operating systems.
Overview
Typing
recover at the DOS
command-line invoked the program file or (depending on the DOS version).
recover proceeded under the assumption that all
directory
Directory may refer to:
* Directory (computing), or folder, a file system structure in which to store computer files
* Directory (OpenVMS command)
* Directory service, a software application for organizing information about a computer network's u ...
information included on a disk or
disk partition was hopelessly corrupted, but that the
FAT and non-directory areas might still contain useful information (though there might be additional bad
disk sectors not recorded in the FAT).
The program removed all subdirectories and all entries in the
root directory
In a computer file system, and primarily used in the Unix and Unix-like operating systems, the root directory is the first or top-most directory in a hierarchy. It can be likened to the trunk of a tree, as the starting point where all branches ...
, and then created new files with names such as "" in the root directory, corresponding to the valid allocation chains that were found in the FAT area (excluding
disk clusters that were tested and found to have hardware errors). A formerly
bootable disk
A boot disk is a removable digital data storage medium from which a computer can load and run (boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting ...
would no longer be bootable after
recover had executed. The range of circumstances in which
recover was genuinely useful was quite limited, and well-meaning DOS users sometimes created havoc by running
recover under the misconception that it was a file
undelete
Undeletion is a feature for restoring computer files which have been removed from a file system by file deletion. Deleted data can be recovered on many file systems, but not all file systems provide an undeletion feature. Recovering data witho ...
utility.
In DOS version 5, another mode of operation was added: specifying a single
filename
A filename or file name is a name used to uniquely identify a computer file in a directory structure. Different file systems impose different restrictions on filename lengths.
A filename may (depending on the file system) include:
* name &ndas ...
on the command line would cause the program to test all the disk sectors used to store the file, and shorten the file by omitting sectors which tested bad.
DR DOS 6.0 includes an implementation of the command.
[DR DOS 6.0 User Guide Optimisation and Configuration Tips](_blank)
/ref> The command is also available on SISNE plus and IBM OS/2. The FreeDOS version was developed by Imre Leber and is licensed under the GPL.
See also
* Chkdsk
* Scandisk
* Norton Utilities
Norton Utilities is a utility software suite designed to help analyze, configure, optimize and maintain a computer. The latest version of the original series of Norton Utilities is Norton Utilities 16 for Windows XP/Vista/7/8 was released 26 Oc ...
* List of DOS commands
References
Further reading
*
*
*
External links
recover , Microsoft DocsOpen source RECOVER implementation that comes with MS-DOS v2.0
{{Windows commands
Disk file systems
External DOS commands
IBM PC compatibles
Microsoft free software
OS/2 commands