|UNGETC(3)||FreeBSD Library Functions Manual||UNGETC(3)|
NAMEungetc — un-get character from input stream
LIBRARYStandard C Library (libc, -lc)
SYNOPSIS#include < stdio.h>
ungetc( int c, FILE *stream);
DESCRIPTIONThe ungetc() function pushes the character c (converted to an unsigned char) back onto the input stream pointed to by stream. The pushed-back 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 ( fseek(3), fsetpos(3), or rewind(3)) will discard the pushed back characters.
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. The file-position indicator is decremented by each successful call to ungetc(); if its value was 0 before a call, its value is unspecified after the call.
RETURN VALUESThe ungetc() 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.
STANDARDSThe ungetc() function conforms to ISO/IEC 9899:1990 (“ISO C90”).
|June 4, 1993||FreeBSD|