HP UX Operating Systems 123

cksum(1)

NAME

cksum - print ®le checksum and sizes

SYNOPSIS

cksum [®le ...]

DESCRIPTION

The cksum command calculates and prints to standard output a checksum for each named ®le, the number of octets in the ®le and the ®lename.

cksum uses a portable algorithm based on a 32-bit Cyclic Redundancy Check. This algorithm ®nds 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 ®le.

x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x7 + x5 + x4 + x2 + x1 + x0

The results of the calculation are truncated to a 32-bit value. The number of bytes in the ®le is also printed.

Standard input is used if no ®le names are given.

cksum is typically used to verify data integrity when copying ®les 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 ®les).

LC_MESSAGES determines the language in which messages are displayed.

If any internationalization variable contains an invalid setting, cksum behaves as if all internationalization variables are set to "C". See environ(5).

RETURN VALUE

Upon completion, cksum returns one of the following values:

0All ®les were processed successfully.

>0 One or more ®les could not be read or another error occurred.

If an inaccessible ®le is encountered, cksum continues processing any remaining ®les, but the ®nal exit status is affected.