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
*file*s
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)