NAME
cmp — compare two files
SYNOPSIS
cmp
[-l]
[-s]
file1 file2
[skip1
[skip2]]
DESCRIPTION
cmp
compares two files (if
file1
or
file2
is
-,
the standard input is used).
Under default options,
cmp
makes no comment if the files are the same;
if they differ, it announces the byte and line number
at which the difference occurred.
If one file is an initial subsequence of the other, that fact is noted.
skip1
and
skip2
are initial byte offsets into
file1
and
file2,
respectively; and maybe octal or decimal;
the form of the number is determined by the
environment variable
LC_NUMERIC
(in the C locale, a leading 0 denotes an
octal number. See
LANG
on
environ(5)
and
strtol(3C)).
cmp
recognizes the following options:
- -l
Print the byte number (decimal) and the differing bytes (octal)
for each difference (byte numbering begins at 1 rather than 0).
- -s
Print nothing for differing files; return codes only.
EXTERNAL INFLUENCES
Environment Variables
LANG
determines the language in which messages are displayed.
If
LANG
is not specified or is set to the empty string,
a default of "C" (see
lang(5))
is used instead of
LANG.
If any internationalization variable contains an invalid setting,
cmp
behaves as if all internationalization variables are set to "C".
See
environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
DIAGNOSTICS
cmp
returns the following exit values:
- 0
Files are identical.
- 1
Files are not identical.
- 2
Inaccessible or missing argument.
cmp
prints the following warning if the comparison succeeds
till the end of file of file1(file2) is reached.
STANDARDS CONFORMANCE
cmp: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2