sum(1)sum(1)NAMEsum - Displays the checksum and byte count in block-size (1024) units
of a file
SYNOPSISsum [-o | -r] [file...]
The sum command reads file and calculates a 16-bit checksum and the
byte count in block-size (1024) units in the file. If the file argu‐
ment is omitted, sum reads standard input.
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
sum: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
[Tru64 UNIX] Uses an algorithm to compute the checksum using word-by-
word computation. Uses an alternate algorithm to compute the checksum
(rigorous byte-by-byte computation rather than the word-by-word compu‐
tation).
[Tru64 UNIX] This is the default.
OPERANDS
The file for which a checksum is to be computed. If this operand is
omitted, standard input is used.
DESCRIPTION
The checksum and number of blocks are written to standard output. The
sum command is generally used to determine if a file that was copied or
communicated over transmission lines is an exact copy of the original.
The sum command writes the space used in 1024-byte units.
[Tru64 UNIX] The checksum is calculated using a rigorous byte-byte
computation by default.
System V Compatibility
[Tru64 UNIX] The checksum algorithms for the default sum command and
the SVID 2 compliant sum command are reversed. The SVID 2 compliant
sum command uses the word-by-word algorithm by default and uses the
byte-by-byte algorithm if you specify the -r option on the command
line.
NOTES
The sum utility is marked LEGACY in XCU Issue 5. [Tru64 UNIX] The
default algorithm is no longer the word-by-word computation algorithm.
It was changed to the 4.3BSD default algorithm. The algorithms used
may not be portable, that is, the same checksum may not be produced for
the same input on different systems. Portable applications should use
cksum.
EXIT STATUS
The following exit values are returned: Successful completion. An
error occurred.
EXAMPLES
To display the checksum of datafile and the number of blocks in this
file, enter: sum datafile
If the checksum of datafile is 1605 and if the file contains 3 blocks,
sum displays: 1605 3 datafile
ENVIRONMENT VARIABLES
The following environment variables affect the execution of sum: Pro‐
vides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from
the default locale is used. If any of the internationalization vari‐
ables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, over‐
rides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
SAGES.
SEE ALSO
Commands: cksum(1), wc(1)
Standards: standards(5)sum(1)
