.Dd January 15, 2017
.Dt DEFLATECOPY 3
.Os
.
.Sh NAME
.Nm deflateCopy
.Nd copy deflate stream
.
.Sh LIBRARY
.Lb libz
.
.Sh SYNOPSIS
.In zlib.h
.Ft int
.Fn deflateCopy "z_streamp dest" "z_streamp source"
.
.Sh DESCRIPTION
Sets the destination stream
as a complete copy of the source stream.
.
.Pp
This function can be useful when
several compression strategies will be tried,
for example when there are several ways of
pre-processing the input data with a filter.
The streams that will be discarded
should then be freed by calling
.Xr deflateEnd 3 .
Note that
.Fn deflateCopy
duplicates the internal compression state
which can be quite large,
so this strategy is slow
and can consume lots of memory.
.
.Sh RETURN VALUES
.Fn deflateCopy
returns
.Dv Z_OK
if success,
.Dv Z_MEM_ERROR
if there was not enough memory,
.Dv Z_STREAM_ERROR
if the source stream state was inconsistent
.Po
such as
.Fa zalloc
being
.Dv Z_NULL
.Pc .
.Fa msg
is left unchanged
in both source and destination.
.
.Sh SEE ALSO
.Xr deflateInit 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