opensolaris man page for ungetwc

ungetwc(3C)						   Standard C Library Functions 					       ungetwc(3C)

NAME
       ungetwc - push wide-character code back into input stream

SYNOPSIS
       #include <stdio.h>
       #include <wchar.h>

       wint_t ungetwc(wint_t wc, FILE *stream);

DESCRIPTION
       The  ungetwc() function pushes the character corresponding to the wide character code specified by wc back onto the input stream pointed to
       by stream. The pushed-back characters will be returned by subsequent reads on that stream in the reverse order of their pushing. A success-
       ful intervening call (with the stream pointed to by stream) to a file-positioning function ( fseek(3C), fsetpos(3C) or rewind(3C)) discards
       any pushed-back characters for the stream. The external storage corresponding to the stream is unchanged.

       One character of push-back is guaranteed. If ungetwc() is called too many times on the same stream without an  intervening  read  or  file-
       positioning operation on that stream, the operation may fail.

       If the value of wc equals that of the macro WEOF, the operation fails and the input stream is unchanged.

       A  successful  call  to	ungetwc() clears the end-of-file indicator for the stream. The value of the file-position indicator for the stream
       after reading or discarding all pushed-back characters will be the same as it was before the characters were pushed back. The file-position
       indicator  is  decremented (by one or more) by each successful call to ungetwc(); if its value was 0 before a call, its value is indetermi-
       nate after the call.

RETURN VALUES
       Upon successful completion, ungetwc() returns the wide-character code corresponding to the  pushed-back	character.  Otherwise  it  returns
       WEOF.

ERRORS
       The ungetwc() function may fail if:

       EILSEQ	 An invalid character sequence is detected, or a wide-character code does not correspond to a valid character.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |ATTRIBUTE TYPE		     |ATTRIBUTE VALUE		   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       read(2), fseek(3C), fsetpos(3C), rewind(3C), setbuf(3C), attributes(5), standards(5)

SunOS 5.11							    14 Aug 2002 						       ungetwc(3C)