.Dd January 15, 2017
.Dt GZUNGETC 3
.Os
.
.Sh NAME
.Nm gzungetc
.Nd un-get character from compressed file
.
.Sh LIBRARY
.Lb libz
.
.Sh SYNOPSIS
.In zlib.h
.Ft int
.Fn gzungetc "int c" "gzFile file"
.
.Sh DESCRIPTION
Push one character back onto the stream
to be read as the first character
on the next read.
At least one character of push-back
is allowed.
.Fn gzungetc
will fail if
.Fa c
is -1,
and may fail if a character
has been pushed
but not read yet.
If
.Fn gzungetc
is used immediately after
.Xr gzopen 3
or
.Xr gzdopen 3 ,
at least the output buffer size
of pushed characters is allowed.
.Po
See
.Xr gzbuffer 3 .
.Pc \&
The pushed character will be discarded
if the stream is repositioned with
.Xr gzseek 3
or
.Xr gzrewind 3 .
.
.Sh RETURN VALUES
.Fn gzungetc
returns the character pushed,
or -1 on failure.
.
.Sh SEE ALSO
.Xr gzbuffer 3 ,
.Xr gzerror 3 ,
.Xr gzgetc 3 ,
.Xr gzopen 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