CMP(1) User Commands CMP(1)
NAME
cmp - compare two files
SYNOPSIS
cmp [
-l |
-s]
file1 file2 [
skip1] [
skip2]
DESCRIPTION
The
cmp utility compares two files.
cmp writes no output if the files
are the same. Under default options, if they differ, it writes to
standard output the byte and line numbers at which the first
difference occurred. Bytes and lines are numbered beginning with 1.
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 can be either octal or decimal. A leading 0 denotes
octal.
OPTIONS
The following options are supported:
-l Write the byte number (decimal) and the differing bytes (octal)
for each difference.
-s Write nothing for differing files. Return exit status only.
OPERANDS
The following operands are supported:
file1 A path name of the first file to be compared. If
file1 is
-,
the standard input is used.
file2 A path name of the second file to be compared. If
file2 is
-, the standard input is used.
If both
file1 and
file2 refer to standard input or refer to the same
FIFO special, block special or character special file, an error
results.
USAGE
See
largefile(7) for the description of the behavior of
cmp when
encountering files greater than or equal to 2 Gbyte (2^31 bytes).
EXAMPLES
Example 1: Comparing Files Byte for Byte
The following example does a byte for byte comparison of
file1 and
file2:
example%
cmp file1 file2 0 1024 It skips the first 1024 bytes in
file2 before starting the
comparison.
ENVIRONMENT VARIABLES
See
environ(7) for descriptions of the following environment
variables that affect the execution of
cmp:
LANG,
LC_ALL,
LC_CTYPE,
LC_MESSAGES, and
NLSPATH.
EXIT STATUS
The following error values are returned:
0 The files are identical.
1 The files are different. This includes the case where one file
is identical to the first part of the other.
>1 An error occurred.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
SEE ALSO
comm(1),
diff(1),
attributes(7),
environ(7),
largefile(7),
standards(7) July 19, 2006 CMP(1)