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ungetwc()
Push a wide character back onto an input stream

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ungetwc()

QNX SDP8.0C Library ReferenceAPIDeveloper

Push a wide character back onto an input stream

Synopsis:

#include <wchar.h>

wint_t ungetwc( wint_t wc,
                FILE * fp );

Arguments:

c: The wide character that you want to push back.
fp: The stream you want to push the wide character back on.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The ungetwc() function pushes the wide character specified by wc back onto the input stream pointed to by fp.

The pushed-back character will be returned the next time that you read from the stream but is discarded if you call fflush() or a file-positioning function (fseek(), fsetpos(), or rewind()) before the next read operation is performed.

Only one character (the most recent one) of pushback is guaranteed.

The ungetwc() function clears the end-of-file indicator, unless the value of wc is WEOF.

Returns:

The character pushed back.

Errors:

EILSEQ: Invalid character sequence or wide character.

Classification:

ANSI, POSIX 1003.1


Safety:
Cancellation point	Yes
Signal handler	No
Thread	Yes

Page updated: March 05, 2025