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HP-UX 11i Version 3: February 2007

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cksum — print file checksum and sizes


cksum [file ...]


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.

  • 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 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.


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 internationalization variables are set to "C". See environ(5).


Upon completion, cksum returns one of the following values:


All files were processed successfully.


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.


sum(1), wc(1).


cksum: XPG4, POSIX.2

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