Content-type: text/html Man page of sum

sum

Section: User Commands (1)
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NAME

sum - Displays the checksum and block count of a file  

SYNOPSIS

sum [-o|-r] [file...]

The sum command reads file and calculates a 16-bit checksum and the number of blocks in the file. If the file argument is omitted, sum reads standard input.
 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

sum:  XPG4, XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.
 

OPTIONS

[Compaq]  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 computation). 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 512-byte units.
 

System V Compatibility

[Compaq]  The root of the directory tree that contains the commands modified for SVID 2 compliance is specified in the file /etc/svid2_path. You can use /etc/svid2_profile as the basis for, or to include in, your .profile. The file /etc/svid2_profile reads /etc/svid2_path and sets the first entries in the PATH environment variable so that the modified SVID 2 commands are found first.

[Compaq]  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

[Compaq]  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: Provides 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 variables contain an invalid setting, the utility behaves as if none of the variables had been defined. If set to a non-empty string value, overrides 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 multibyte characters in arguments). Determines the locale for the format and contents of diagnostic messages written to standard error. Determines the location of message catalogues for the processing of LC_MESSAGES.
 

SEE ALSO

Commands:  cksum(1), wc(1)

Standards:  standards(5)


 

Index

NAME
SYNOPSIS
STANDARDS
OPTIONS
OPERANDS
DESCRIPTION
System V Compatibility
NOTES
EXIT STATUS
EXAMPLES
ENVIRONMENT VARIABLES
SEE ALSO

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Time: 02:42:59 GMT, October 02, 2010