2.11BSD/src/local/zmodem/crc.1

.TH CRC 1 OMEN 
.SH NAME
crc \- checksum files
.SH SYNOPSIS
.B crc
file ...
.SH DESCRIPTION
For each file,
.I crc\^
calculates and prints a 32-bit CRC,
the byte count, and the file name.
It is typically used to validate files transferred between
different systems, and is useful in detecting subtle disk corruption.
.I Crc\^
uses a checksum compatible with the
DOS
version of crc,
the 32 bit CRC used by PKZIP version 0.9,
as well as the "crc" command in ZCOMM and Professional-YAM
(high reliability communications programs).

The 32-bit CRC used is the frame
check sequence in ADCCP (ANSI X3.66, also known as FIPS PUB 71
and FED-STD-1003, the U.S. versions of CCITT's X.25 link-level
protocol).

32 bit CRC code courtesy Gary S. Brown.
.SH BUGS
Although extremely unlikely,
files with different data may still produce the same crc value.
.SH "SEE ALSO"
chek(1), undos(OMEN), todos(OMEN), tocpm(OMEN), sum(1), wc(1).