Comp (command)

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

The ReactOS comp command
Developer(s)	DEC, IBM, Microsoft, Digital Research, Novell, Paul Vojta, ReactOS Contributors
Initial release	August 1981; 43 years ago (1981-08)
Operating system	OS/8, PC DOS, MS-DOS, FlexOS, SISNE plus, OS/2, eComStation, ArcaOS, Windows, DR DOS, FreeDOS, ReactOS
Platform	Cross-platform
Type	Command
License	FreeDOS: MIT ReactOS: GNU GPL 2

History

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]

Syntax

The command-syntax is:^[12]

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

Parameters

• <Data1> – Location and name of the first file or set of files
• <Data2> – Location and name of the second file or set of files
• /d – Display differences in decimal format (Default is hexadecimal)
• /a – Display differences as characters
• /l – Display the number of the line, instead of the byte offset
• /n=<Number> – Compare only the specified number of lines for each file
• /c – Perform a non case-sensitive comparison
• /off[line] – Process files with the offline attribute set
• /? – Display Help

See also

• Data comparison
• List of DOS commands
• diff

References

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. http://www.bitsavers.org/pdf/digitalResearch/flexos/1073-2003_FlexOS_Users_Guide_V1.3_Nov86.pdf Archived 2019-09-25 at the Wayback Machine ^{[bare URL PDF]}
4. "OS/2 Commands". www.jatomes.com. 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. http://www.bitsavers.org/pdf/ibm/pc/dos/6172220_DOS_1.0_Jan82.pdf ^{[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)". Ibiblio.org. 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

• Cooper, Jim (2001). Special Edition Using MS-DOS 6.22, Third Edition. Que Publishing. ISBN 978-0789725738.
• Dyson, Peter (1995). Mastering OS/2 Warp. Sybex. ISBN 978-0782116632.
• Stanek, William R. (2008). Windows Command-Line Administrator's Pocket Consultant, 2nd Edition. Microsoft Press. ISBN 978-0735622623.

External links

• comp | Microsoft Docs