_ungetch

Pushes back the last charcter read from the console.

int_ungetch(intc**);**

For additional compatibility information, see Compatibility in the Introduction.

Libraries

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

Console and Port I/O Routines

See Also   _cscanf, _getch