.Dd January 15, 2017
.Dt ADLER32_COMBINE 3
.Os
.
.Sh NAME
.Nm adler32_combine
.Nd combine Adler-32 checksums
.
.Sh LIBRARY
.Lb libz
.
.Sh SYNOPSIS
.In zlib.h
.Ft uLong
.Fn adler32_combine "uLong adler1" "uLong adler2" "z_off_t len2"
.
.Sh DESCRIPTION
Combine two Adler-32 checksums into one.
For two sequences of bytes,
.Va seq1
and
.Va seq2
with lengths
.Va len1
and
.Va len2 ,
Adler-32 checksums were calculated for each,
.Va adler1
and
.Va adler2 .
.Fn adler32_combine
returns the Adler-32 checksum of
.Va seq1
and
.Va seq2
concatenated,
requiring only
.Fa adler1 ,
.Fa adler2 ,
and
.Fa len2 .
Note that the
.Vt z_off_t
type
.Pq like Vt off_t
is a signed integer.
If
.Fa len2
is negative,
the result has no meaning or utility.
.
.Sh SEE ALSO
.Xr adler32 3
.
.Sh HISTORY
This manual page was converted from
.In zlib.h
to mdoc format by
.An C. McEnroe Aq Mt june@causal.agency .
.
.Sh AUTHORS
.An Jean-loup Gailly Aq Mt jloup@gzip.org
.An Mark Adler Aq Mt madler@alumni.caltech.edu