SUM(1)SUM(1)
NAME
sum, md5sum, sha1sum – sum and count blocks in a file
SYNOPSIS
sum
[
-5r
]
[
file ...
]
md5sum
[
file ...
]
sha1sum
[
-2
bits
] [
file ...
]
DESCRIPTION
By default,
sum
calculates and prints a 32-bit hexadecimal checksum,
a byte count,
and the name of
each
file.
The checksum is also a function of the input length.
If no
files
are given,
the standard input is
summed.
Other summing algorithms are available.
The options are
-r
Sum with the algorithm of System V’s
sum -r
and print the length (in 1K blocks) of the input.
-5
Sum with System V’s default algorithm
and print the length (in 512-byte blocks) of the input.
Sum
is typically used to look for bad spots,
to validate a file communicated over
some transmission line or
as a quick way to determine if two files on different machines might be the same.
Md5sum
computes the 32 hex digit RSA Data Security, Inc. MD5 Message-Digest Algorithm
described in RFC1321.
Sha1sum
computes the 40 hex digit National Institute of Standards and Technology
(NIST)
SHA1 secure hash algorithm
described in FIPS PUB 180-1,
by default.
Given the
2
option,
it instead computes the
bits-bit
NIST SHA2 secure hash algorithm
described in FIPS PUB 180-2
and prints the hash in hex.
Currently supported values of
bits
are
224,
256,
384,
and
512.
SOURCE
/sys/src/cmd/sum.c
/sys/src/cmd/md5sum.c
/sys/src/cmd/sha1sum.c
SEE ALSO
cmp(1),
wc(1),
sechash(2)