.TH UNGETC 3S .SH NAMEungetc \- push character back into input stream.SH SYNOPSIS.B #include <stdio.h>.PP.B ungetc(c, stream).br.SM.B FILE.B *stream;.SH DESCRIPTION.I Ungetcpushes the character.I cback on an input stream.That character will be returned by the next.I getccall on that stream..I Ungetc returns .IR c ..PPOne character of pushback is guaranteed providedsomething has been read from the stream and the stream isactually buffered.Attempts to push EOF are rejected..PP.IR  Fseek (3)erases all memory of pushed back characters..SH "SEE ALSO"getc(3), setbuf(3), fseek(3).SH DIAGNOSTICS.I Ungetcreturns.SM.B EOFif it can't push a character back.