ungetch
函数名: ungetch
功 能: 把一个字符退回到键盘缓冲区中
用 法: int ungetch(int c);
程序例:
#include
#include
#include
int main( void )
{
int i=0;
char ch;
puts("Input an integer followed by a char:");
/* read chars until non digit or EOF */
while((ch = getche()) != EOF && isdigit(ch))
i = 10 * i + ch - 48; /* convert ASCII into int value */
/* if non digit char was read, push it back into input buffer */
if (ch != EOF)
ungetch(ch);
printf("
i = %d, next char in buffer = %c
", i, getch());
return 0;
}