Sum (Unix)

Sum is a core Unix utility available on all Unix and Linux distributions. There is a GNU utility written by Kayvan Aghaiepour and David MacKenzie and distributed with the UNIX- and Linux-based operating systems. This utility outputs the checksum of each argument file, as well as the number of blocks they take on disk.^[1]

According to the manual page,^[1] sum uses two different algorithms for calculating the checksum and blocks, the SYSV checksum algorithm and the BSD checksum (default) algorithm. Switching between the two algorithms is done via command line options.

The algorithms implemented in this program are less sensitive than more modern checksum methods; the SYSV algorithm does not even depend on the order of the data. The GNU manual page states: "sum is provided for compatibility; the cksum program is preferable in new applications".

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

1 2 sum(1) — manual pages from GNU coreutils

External links

sum(1) — manual pages from GNU coreutils

Unix command-line interface programs and shell builtins

File system	cat chmod chown chgrp cksum cmp cp dd du df file fsck fuser ln ls mkdir mount mv pax pwd rm rmdir split tee touch type umask

Processes	at bg chroot cron fg kill killall nice pgrep pkill ps pstree time top

User environment	clear env exit finger history logname mesg passwd su sudo uptime talk tput uname w wall who whoami write

Text processing	awk banner basename comm csplit cut diff dirname ed ex fmt fold head iconv join less more nl paste printf sed sort spell strings tail tr uniq vi wc xargs yes

Shell builtins	alias cd echo test unset wait

Networking	dig host ifconfig inetd netcat netstat nslookup ping rdate rlogin route ssh traceroute

Searching	find grep locate whatis whereis

Documentation	apropos help man

Miscellaneous	bc dc cal expr lp od sleep true and false

List of Unix commands

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Sum (Unix)

See also

References

External links