recover (command)
{{lowercase title}}
{{Infobox software
| name = recover
| logo =
| screenshot =
| screenshot size =
| caption =
| author = Chris Peters
| developer = Microsoft, IBM, Digital Research, Novell, Imre Leber
| released = {{Release year|df=yes|1983}}
| latest release version =
| latest release date =
| programming language = MS-DOS: x86 assembly language
| operating system = MS-DOS, PC DOS, SISNE plus, OS/2, eComStation, ArcaOS, Windows, DR DOS, FreeDOS
| platform = Cross-platform
| genre = Command
| license = MS-DOS: MIT
FreeDOS: GPL
| website = {{URL|https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/recover}}
}}
In computing, recover
is a primitive file system error recovery utility{{Cite web|url=https://ss64.com/nt/recover.html|title=Recover - Restore damaged data - Windows CMD - SS64.com|website=ss64.com}} included in MS-DOS / IBM PC DOS versions prior to DOS 6.0{{cite web |url=http://support.microsoft.com/kb/71986 |title=MS-DOS 5.0 Internal and External Commands |website=support.microsoft.com |url-status=dead |archive-url=https://web.archive.org/web/20070206024045/http://support.microsoft.com/kb/71986 |archive-date=2007-02-06}} and a number of other operating systems.
Overview
Typing recover
at the DOS command-line invoked the program file {{mono|RECOVER.COM}} or {{mono|RECOVER.EXE}} (depending on the DOS version). recover
proceeded under the assumption that all directory 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, and then created new files with names such as "{{mono|FILE0001.REC}}" 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 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 utility.{{Cite web | url=http://www.drsolly.com/story/macedpcp.art | format=TXT | title=Explore captures for this URL | archive-url=https://web.archive.org/web/20120426031601/http://www.drsolly.com/story/macedpcp.art | archive-date=2012-04-26}}
In DOS version 5, another mode of operation was added: specifying a single filename 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.DOS 5 User's Guide by Dan Gookin (1991), {{ISBN|1-55851-188-1}}, p. 602.
DR DOS 6.0 includes an implementation of the {{code|recover}} command.[https://www.4corn.co.uk/archive/docs/DR%20DOS%206.0%20User%20Guide-opt.pdf DR DOS 6.0 User Guide Optimisation and Configuration Tips] The command is also available on SISNE plus[https://datassette.org/manuais/ibm-pc/sisne-plus-referencia-sumaria SISNE plus - Referência Sumária | Datassette] and IBM OS/2.{{cite web |url=http://www.jatomes.com/Help/Os2Cmd.php#RECOVER |title=JaTomes Help - OS/2 Commands |website=www.jatomes.com |url-status=dead |archive-url=https://web.archive.org/web/20190414130029/http://www.jatomes.com/Help/Os2Cmd.php |archive-date=2019-04-14}} The FreeDOS version was developed by Imre Leber and is licensed under the GPL.{{cite web|url=http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/recover.html |title=FreeDOS 1.2 Updates Package - recover (FreeDOS Base) |publisher=Ibiblio.org |date=2004-02-07 |accessdate=2022-09-04}}
See also
References
{{Reflist|2}}
Further reading
- {{Cite book|author-last=Cooper|author-first=Jim|title=Special Edition Using MS-DOS 6.22, Third Edition|date=2001|publisher=Que Publishing|isbn=978-0789725738}}
- {{Cite book|author1=Kathy Ivens|author2=Brian Proffit|year=1993|title=OS/2 Inside & Out|publisher=Osborne McGraw-Hill|isbn=978-0078818714}}
- {{Cite book|author=John Paul Mueller|year=2007|title=Windows Administration at the Command Line for Windows Vista, Windows 2003, Windows XP, and Windows 2000|publisher=John Wiley & Sons|isbn=978-0470165799}}
External links
{{Wikibooks|Guide to Windows Commands}}
- [https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/recover recover | Microsoft Docs]
- [https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/RECOVER.ASM Open source RECOVER implementation that comes with MS-DOS v2.0]
{{Windows commands}}
Category:External DOS commands