Cmp (Unix)

cmp is a command line utility for computer systems that use Unix or a Unix-like operating system. It compares two files of any type and writes the results to the standard output. By default, cmp is silent if the files are the same; if they differ, the byte and line number at which the first difference occurred is reported.

Switches

cmp may be qualified by the use of command-line switches. The switches supported by the GNU version of cmp are:

<code>-b, --print-bytes</code>

Print differing bytes.

<code>-i SKIP, --ignore-initial=SKIP</code>

Skip the first SKIP bytes of input.

<code>-i SKIP1

SKIP2, --ignore-initial=SKIP1

<code>-l, --verbose</code>

Output byte numbers and values of all differing bytes.

<code>-n LIMIT, --bytes=LIMIT</code>

Compare at most LIMIT bytes.

<code>-s, --quiet, --silent</code>

Output nothing; yield exit status only.

<code>-v, --version</code>

Output version info.

<code>--help</code>

Outputs a help file.

Return values

• 0 - files are identical
• 1 - files differ
• 2 - inaccessible or missing argument

See also

• Comparison of file comparison tools
• List of Unix programs

References

External links

• The section of the manual of GNU cmp in the diffutils free manual.

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