sum (Unix)

sum
Original author(s)	Ken Thompson
Developer(s)	AT&T Bell Laboratories
Initial release	November 3, 1971; 50 years ago
Operating system	Unix, Unix-like, Inferno
Platform	Cross-platform
Type	Command
License	coreutils: GPLv3+

sum is a legacy utility available on some Unix and Unix-like operating systems. This utility outputs the checksum of each argument file, as well as the number of blocks they take on disk.^[1]

Overview[]

The sum program is generally only useful for historical interest. It is not part of POSIX. Two algorithms are typically available: a 16-bit BSD checksum and a 32-bit SYSV checksum. Both are weaker than the (already weak) CRC32 used by cksum.^[2]

The default algorithm on FreeBSD and GNU implementations is the weaker BSD checksum. Switching between the two algorithms is done via command line options.^[2]^[1]

Syntax[]

The sum utility is invoked from the command line according to the following syntax:

sum [OPTION]... [FILE]...

with the possible option parameters being:

-r
- use BSD checksum algorithm, use 1K blocks (defeats -s)
-s, --sysv
- use SYSV checksum algorithm, use 512 bytes blocks
--help
- display the help screen and exit
--version
- output version information and exit

When no file parameter is given, or when FILE is -, the standard input is used as input file.

References[]

^ ^a ^b sum(1) — manual pages from GNU coreutils
^ ^a ^b sum(1) – FreeBSD General Commands Manual

External links[]

sum(1) — manual pages from GNU coreutils

[sum-invocation-1] sum(1) — manual pages from GNU coreutils

[fbsd-2] sum(1) – FreeBSD General Commands Manual

[1]

[2]

v t Unix command-line interface programs and shell builtins
File system	cat chmod chown chgrp cksum cmp cp dd du df file fuser ln ls mkdir mv pax pwd rm rmdir split tee touch type umask
Processes	at bg crontab fg kill nice ps time
User environment	env exit logname mesg talk tput uname who write
Text processing	awk basename comm csplit cut diff dirname ed ex fold head iconv join m4 more nl paste patch printf sed sort strings tail tr uniq vi wc xargs
Shell builtins	alias cd echo test unset wait
Searching	find grep
Documentation	man
Software development	ar ctags lex make nm strip yacc
Miscellaneous	bc cal expr lp od sleep true and false
Categories Standard Unix programs Unix SUS2008 utilities List

v t GNU Core Utilities command-line interface programs
File system	chmod chown chgrp cksum cp dd df dir install ln ls mkdir mkfifo mknod mktemp mv rm rmdir shred sync touch truncate vdir
Text utilities	base32 base64 cat cksum comm csplit cut expand fmt fold head join md5sum nl od paste ptx pr sha1sum shuf sort split sum tac tail tr tsort unexpand uniq wc
Shell utilities	arch basename chroot date dirname du echo env expr factor false groups id link logname nice nohup printenv printf pwd seq sleep stat tee test timeout true tty uname unlink uptime users who whoami yes

sum (Unix)

Contents

Overview[]

Syntax[]

See also[]

References[]

External links[]