int
ungetc(
int c
, FILE *stream
)
)
function pushes the character
c
(converted to an unsigned char)
back onto the input stream pointed to by
stream
.
The pushed-backed characters will be returned by subsequent reads on the
stream (in reverse order).
A successful intervening call, using the same stream, to one of the file
positioning functions
href="../html3/fsetpos.html">fsetpos(3), or rewind(3)
(fseek(3),
One character of push-back is guaranteed,
but as long as there is
sufficient memory, an effectively infinite amount of pushback is allowed.
If a character is successfully pushed-back, the end-of-file indicator for the stream is cleared.
)
function
returns
the character pushed-back after the conversion, or
EOF
if the operation fails.
If the value of the argument
c
character equals
EOF
,
the operation will fail and the stream will remain unchanged.
)
function conforms to
ANSI X3.159-1989 (``ANSI C89'') .