sum, md5sum, sha1sum – sum and count blocks in a file|
sum [ −5r ] [ file ... ]
md5sum [ file ... ]
sha1sum [ file ... ]|
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
−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. If no files are given, the standard
input is summed.
Sha1sum computes the 40 hex digit National Institute of Standards
and Technology SHA1 secure hash algorithm described in FIPS PUB
180-1. If no files are given, the standard input is summed.