Command Reference Guide
__________________________________________________________________________________________________________________________________________________________________________________________________
__________________________________________________________________________________________________________________________________________________________________________________________________
STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1/!!!intro.1
________________________________________________________________
___ ___
c
cksum(1) cksum(1)
NAME
cksum - print file checksum and sizes
SYNOPSIS
cksum [file ...]
DESCRIPTION
The cksum command calculates and prints to standard output a checksum for each named file, the number
of octets in the file and the filename.
cksum uses a portable algorithm based on a 32-bit Cyclic Redundancy Check. This algorithm finds a
broader spectrum of errors than the 16-bit algorithms used by sum (see sum(1)). The CRC is the sum of
the following expressions, where x is each byte of the file.
x
32
+ x
26
+ x
23
+ x
22
+ x
16
+ x
12
+ x
11
+ x
10
+ x
7
+ x
5
+ x
4
+ x
2
+ x
1
+ x
0
The results of the calculation are truncated to a 32-bit value. The number of bytes in the file is also
printed.
Standard input is used if no file names are given.
cksum is typically used to verify data integrity when copying files between systems.
EXTERNAL INFLUENCES
Environment Variables
LANG determines the locale to use for the locale categories when both LC_ALL and the corresponding
environment variable (beginning with LC_) do not specify a locale. If LANG is not set or is set to the
empty string, a default of "C" (see lang(5)) is used.
LC_CTYPE determines the locale for interpretation of sequences of bytes of text data as characters (e.g.,
single- verses multibyte characters in arguments and input files).
LC_MESSAGES determines the language in which messages are displayed.
If any internationalization variable contains an invalid setting,
cksum behaves as if all internationaliza-
tion variables are set to "C". See environ(5).
RETURN VALUE
Upon completion,
cksum returns one of the following values:
0 All files were processed successfully.
>0 One or more files could not be read or another error occurred.
If an inaccessible file is encountered, cksum continues processing any remaining files, but the final exit
status is affected.
SEE ALSO
sum(1), wc(1), pdf(4).
STANDARDS CONFORMANCE
cksum: XPG4, POSIX.2
HP-UX Release 11i: December 2000 − 1 − Section 1−−95
___
___