Pushes back the last charcter read from the console.
int _ungetch( int c );
| Routine | Required Header | Compatibility |
| _ungetch | <conio.h> | Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
_ungetch returns the character c if it is successful. A return value of EOF indicates an error.
Parameter
c
Character to be pushed
Remarks
The _ungetch function pushes the character c back to the console, causing c to be the next character read by _getch or _getche. _ungetch fails if it is called more than once before the next read. The c argument may not be EOF.
Example
/* UNGETCH.C: In this program, a white-space delimited
* token is read from the keyboard. When the program
* encounters a delimiter, it uses _ungetch to replace
* the character in the keyboard buffer.
*/
#include <conio.h>
#include <ctype.h>
#include <stdio.h>
void main( void )
{
char buffer[100];
int count = 0;
int ch;
ch = _getche();
while( isspace( ch ) ) /* Skip preceding white space. */
ch = _getche();
while( count < 99 ) /* Gather token. */
{
if( isspace( ch ) ) /* End of token. */
break;
buffer[count++] = (char)ch;
ch = _getche();
}
_ungetch( ch ); /* Put back delimiter. */
buffer[count] = '\0'; /* Null terminate the token. */
printf( "\ntoken = %s\n", buffer );
}
Output
White
token = White