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