diffutils: cmp Options
12.1 Options to 'cmp'
=====================
Below is a summary of all of the options that GNU 'cmp' accepts. Most
options have two equivalent names, one of which is a single letter
preceded by '-', and the other of which is a long name preceded by '--'.
Multiple single letter options (unless they take an argument) can be
combined into a single command line word: '-bl' is equivalent to '-b
-l'.
'-b'
'--print-bytes'
Print the differing bytes. Display control bytes as a '^' followed
by a letter of the alphabet and precede bytes that have the high
bit set with 'M-' (which stands for "meta").
'--help'
Output a summary of usage and then exit.
'-i SKIP'
'--ignore-initial=SKIP'
Ignore any differences in the first SKIP bytes of the input files.
Treat files with fewer than SKIP bytes as if they are empty. If
SKIP is of the form 'FROM-SKIP:TO-SKIP', skip the first FROM-SKIP
bytes of the first input file and the first TO-SKIP bytes of the
second.
'-l'
'--verbose'
Output the (decimal) byte numbers and (octal) values of all
differing bytes, instead of the default standard output. Each
output line contains a differing byte's number relative to the
start of the input, followed by the differing byte values. Byte
numbers start at 1. Also, output the EOF message if one file is
shorter than the other.
'-n COUNT'
'--bytes=COUNT'
Compare at most COUNT input bytes.
'-s'
'--quiet'
'--silent'
Do not print anything; only return an exit status indicating
whether the files differ.
'-v'
'--version'
Output version information and then exit.
In the above table, operands that are byte counts are normally
decimal, but may be preceded by '0' for octal and '0x' for hexadecimal.
A byte count can be followed by a suffix to specify a multiple of
that count; in this case an omitted integer is understood to be 1. A
bare size letter, or one followed by 'iB', specifies a multiple using
powers of 1024. A size letter followed by 'B' specifies powers of 1000
instead. For example, '-n 4M' and '-n 4MiB' are equivalent to '-n
4194304', whereas '-n 4MB' is equivalent to '-n 4000000'. This notation
is upward compatible with the SI prefixes
(http://www.bipm.fr/enus/3_SI/si-prefixes.html) for decimal multiples
and with the IEC 60027-2 prefixes for binary multiples
(http://physics.nist.gov/cuu/Units/binary.html).
The following suffixes are defined. Large sizes like '1Y' may be
rejected by your computer due to limitations of its arithmetic.
'kB'
kilobyte: 10^3 = 1000.
'k'
'K'
'KiB'
kibibyte: 2^10 = 1024. 'K' is special: the SI prefix is 'k' and
the IEC 60027-2 prefix is 'Ki', but tradition and POSIX use 'k' to
mean 'KiB'.
'MB'
megabyte: 10^6 = 1,000,000.
'M'
'MiB'
mebibyte: 2^20 = 1,048,576.
'GB'
gigabyte: 10^9 = 1,000,000,000.
'G'
'GiB'
gibibyte: 2^30 = 1,073,741,824.
'TB'
terabyte: 10^12 = 1,000,000,000,000.
'T'
'TiB'
tebibyte: 2^40 = 1,099,511,627,776.
'PB'
petabyte: 10^15 = 1,000,000,000,000,000.
'P'
'PiB'
pebibyte: 2^50 = 1,125,899,906,842,624.
'EB'
exabyte: 10^18 = 1,000,000,000,000,000,000.
'E'
'EiB'
exbibyte: 2^60 = 1,152,921,504,606,846,976.
'ZB'
zettabyte: 10^21 = 1,000,000,000,000,000,000,000
'Z'
'ZiB'
2^70 = 1,180,591,620,717,411,303,424. ('Zi' is a GNU extension to
IEC 60027-2.)
'YB'
yottabyte: 10^24 = 1,000,000,000,000,000,000,000,000.
'Y'
'YiB'
2^80 = 1,208,925,819,614,629,174,706,176. ('Yi' is a GNU extension
to IEC 60027-2.)