sum(1) - Plan 9 from User Space

| SUM(1) | SUM(1)
| NAME
| sum, md5sum, sha1sum – sum and count blocks in a file
SYNOPSIS
| `sum` [ `−5r` ] [ file ... ]
`md5sum` [ file ... ]
`sha1sum` [ 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. 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.
SOURCE
| `/usr/lib/plan9/src/cmd/sum.c /usr/lib/plan9/src/cmd/md5sum.c /usr/lib/plan9/src/cmd/sha1sum.c`
SEE ALSO
| cmp(1), wc(1)