我做了一个程序,找到了gets(),并使用了它,它很棒,但是当我编译程序时它说gets是危险的,所以我搜索了一个替代方案,即使gets()函数使它具有正确的输出,为了将来我宁愿使用一个不危险的替代方法,那是我偶然发现 fgets() 的时候。我认为代码会编译相同并具有相同的输出,但是没有输出我的 if 语句。
代码如下:
#include <stdio.h>
#include <string.h>
int main()
{
char qOne[10];
char qTwo[10];
char guess[40] = "My guess is that you are thinking of a\0";
printf("TWO QUESTIONS\n");
printf("Think of an object, and i'll try to guess it.\n\n");
printf("Question 1) Is it an animal, vegetable, or mineral?\n");
printf("\n> ");
//gets(qOne);
fgets(qOne, 10, stdin);
printf("\nQuestion 2) Is it bigger than a breadbox? (yes/no)\n");
printf("\n> ");
//gets(qTwo);
fgets(qTwo, 10, stdin);
printf("\n");
if(strcmp(qOne, "animal") == 0 && strcmp(qTwo, "no") == 0 ||strcmp(qOne, "animal") == 0 && strcmp(qTwo, "No") == 0)
printf("%s squirrel.\n", guess);
else if(strcmp(qOne, "animal") == 0 && strcmp(qTwo, "yes") == 0 ||strcmp(qOne, "animal") == 0 && strcmp(qTwo, "Yes") == 0)
printf("%s moose.\n", guess);
else if(strcmp(qOne, "vegetable") == 0 && strcmp(qTwo, "no") == 0 ||strcmp(qOne, "vegetable") == 0 && strcmp(qTwo, "No") == 0)
printf("%s carrot.\n", guess);
else if(strcmp(qOne, "vegetable") == 0 && strcmp(qTwo, "yes") == 0 ||strcmp(qOne, "vegetable") == 0 && strcmp(qTwo, "Yes") == 0)
printf("%s watermelon.\n", guess);
else if(strcmp(qOne, "mineral") == 0 && strcmp(qTwo, "no") == 0 ||strcmp(qOne, "mineral") == 0 && strcmp(qTwo, "No") == 0)
printf("%s paper clip.\n", guess);
else if(strcmp(qOne, "mineral") == 0 && strcmp(qTwo, "yes") == 0 ||strcmp(qOne, "mineral") == 0 && strcmp(qTwo, "Yes") == 0)
printf("%s Camaro.\n", guess);
printf("\nI would ask you if I'm right, but I don't actually care.\n");
return 0;
}
此代码的输出是(输入字符串“animal”和“yes”):
TWO QUESTIONS
Think of an object, and i'll try to guess it.
Question 1) Is it an animal, vegetable, or mineral?
> animal
Question 2) Is it bigger than a breadbox? (yes/no)
> yes
I would ask you if I'm right, but I don't actually care.
然而,当我只使用 gets() 而不是 fgets() 时,我的代码给出了正确的输出,即:
TWO QUESTIONS
Think of an object, and i'll try to guess it.
Question 1) Is it an animal, vegetable, or mineral?
> animal
Question 2) Is it bigger than a breadbox? (yes/no)
> yes
My guess is that you are thinking of a moose.
I would ask you if I'm right, but I don't actually care.
如何使用 fgets() 获得相同的输出?
最佳答案
fgets()
保留结束行 '\n'
而 gets()
不保留。然后比较失败。 @user3121023添加代码以消除潜在的结束行。
if (fgets(qTwo, sizeof qTwo, stdin) == NULL) Handle_EOF();
qTwo[strcspn(qTwo, "\n")] = 0;
Removing trailing newline character from fgets() input
[编辑]
备注@Keith Thompson上面关于输入行过长的评论。
关于c - 为什么 gets() 可以正常工作,而 fgets() 却不能?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32340168/