term% cat index.txt SUM(1) General Commands Manual 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 commuâ
nicated 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 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)
SUM(1)