Developer(s)DEC, IBM, Microsoft, Digital Research, Novell, Paul Vojta, ReactOS Contributors
Initial releaseAugust 1981; 42 years ago (1981-08)
Operating systemOS/8, PC DOS, MS-DOS, FlexOS, SISNE plus, OS/2, eComStation, ArcaOS, Windows, DR DOS, FreeDOS, ReactOS
LicenseFreeDOS: MIT
ReactOS: GNU GPL 2

In computing, comp is a command used on DEC OS/8,[1] DOS,[2] DR FlexOS,[3] IBM OS/2,[4] Microsoft Windows[5] and related computer operating systems such as ReactOS. It is used to perform comparisons of multiple computer files to show the differences between them.[6]


COMP.COM (among other commands) in IBM PC DOS 1.0.

In DOS, the comp command first appeared in PC DOS 1.0[7] and has been included in most versions of MS-DOS and PC DOS. A newer command, fc was added in DOS 3.3 which allows for line comparisons in addition to binary comparisons. DR DOS 6.0 also includes an implementation of the comp command.[8]

The FreeDOS version was developed by Paul Vojta and is licensed under the MIT License.[9] Ged Murphy developed the ReactOS version. It is licensed under the GNU GPL 2.[10]

The command is also available in the EFI shell.[11]


The command-syntax is:[12]

comp [<Data1>] [<Data2>] [/d] [/a] [/l] [/n=<Number>] [/c]


See also


  1. ^ "Concise Command Language" (CCL)."OS/8 Handbook" (PDF). April 1974. Retrieved 28 November 2017.
  2. ^ Jamsa, Kris A. (1993), DOS: The Complete Reference, Osborne McGraw-Hill, p. 206, ISBN 0078819040.
  3. ^ Archived 2019-09-25 at the Wayback Machine [bare URL PDF]
  4. ^ "OS/2 Commands". Archived from the original on 2019-04-14. Retrieved 2019-07-20.
  5. ^ "Comp".
  6. ^ Wolverton, Van (2003). Running MS-DOS Version 6.22 (20th Anniversary Edition), 6th Revised edition. Microsoft Press. ISBN 0-7356-1812-7.
  7. ^ [bare URL PDF]
  8. ^ "DR DOS 6.0 User Guide Optimisation and Configuration Tips" (PDF). Archived from the original (PDF) on 2019-09-30. Retrieved 2019-08-13.
  9. ^ "FreeDOS 1.2 Updates Package - comp (FreeDOS Base)". 2006-10-21. Retrieved 2022-09-04.
  10. ^ "Reactos/Reactos". GitHub. 3 January 2022.
  11. ^ "EFI Shells and Scripting". Intel. Retrieved 2013-09-25.
  12. ^ MS-DOS and Windows command line comp command

Further reading