def.c

linux下的Ｃ语言开发

/*-*/
/********************************************************
 * Question:						*
 *	Why does the following program *not* print	*
 *	an error message when an incorrect command is	*
 *	entered?  Hint:  There is a reason we put this	*
 *	in the *goto* section.				*
 ********************************************************/
/*+*/
#include <stdio.h>
#include <stdlib.h>		

int main()
{
    char  line[10];

    while (1) {
	printf("Enter add(a), delete(d), quit(q): ");
	fgets(line, sizeof(line), stdin);

	switch (line[0]) {
	case 'a':
	    printf("Add\n");
	    break;
	case 'd':
	    printf("Delete\n");
	    break;
	case 'q':
	    printf("Quit\n");
	    exit(0);
        defualt:
	    printf("Error:Bad command %c\n", line[0]);
	    break;
	}
    }
}