fflush函数

清除文件缓冲区，文件以写方式打开时将缓冲区内容写入文件 ]

原型:int fflush(FILE *stream)

用法：
/* FFLUSH.C */

#include
#include

void main( void )
{
int integer;
char string[81];

/* Read each word as a string. */
printf( "Enter a sentence of four words with scanf: " );
for( integer = 0; integer < 4; integer++ )
{
scanf( "%s", string );
printf( "%s\n", string );
}

/* You must flush the input buffer before using gets. */
fflush( stdin );
printf( "Enter the same sentence with gets: " );
gets( string );
printf( "%s\n", string );
}


输出：

Enter a sentence of four words with scanf: This is a test
This
is
a
test
Enter the same sentence with gets: This is a test
This is a test