.TH SUM 1L "GNU Text Utilities" "FSF" \" -*- nroff -*-
.SH NAME
sum \- checksum and count the blocks in a file
.SH SYNOPSIS
.B sum
[\-rs] [\-\-sysv] [\-\-help] [\-\-version] [file...]
.SH DESCRIPTION
This manual page
documents the GNU version of
.BR sum .
.B sum
computes a 16-bit checksum for each named file, or the standard input
if none are given or when a file named `\-' is given.  It prints the
checksum for each file along with the number of blocks in the file
(rounded up).
By default each corresponding file name is also printed if at least two
arguments are specified.
With the
.I "\-\-sysv"
option, corresponding file name are printed when there is at least
one file argument.  By
default, the GNU
.B sum
computes checksums using an algorithm that is compatible with the BSD
.B sum
and prints file sizes in units of 1K blocks.
.SS OPTIONS
.TP
.I \-r
Use the default (BSD compatible) algorithm.  This option is included
for compatibility with the System V
.BR sum .
Unless the
.I \-s
option was also given, it has no effect.
.TP
.I "\-s, \-\-sysv"
Compute checksums using an algorithm that is compatible with the one
the System V
.B sum
uses by default
and print file sizes in units of 512-byte blocks instead of 1K.
.TP
.I "\-\-help"
Print a usage message and exit with a non-zero status.
.TP
.I "\-\-version"
Print version information on standard error then exit.