问题
I want to get rid of buffer overflow and I am using fgets instead of scanf to limit the characters. But whenever I enter something with scanf before fgets, it doesn't work correctly anymore.
This code works correctly
#include <stdio.h>
int main()
{
char name[10];
printf("Who are you? \n");
fgets(name,10,stdin);
printf("Good to meet you, %s.\n",name);
return(0);
}
This code does not read name correctly
#include <stdio.h>
#include <stdlib.h>
#define MAX 15
int new_acc();
int view_list();
int main(){
int one=1, two=2, three=3, four=4, five=5, six=6, seven=7, choice;
int new_account, list;
printf("%d. Create new account\n",one);
printf("Enter you choice: ");
scanf("%d",&choice);
if (choice==one){new_account = new_acc();}
return 0;
}
int new_acc(){
char name[MAX], address, account;
printf("Enter your name: ");
fgets(name, MAX, stdin); /* it is the code */
}
Why is it happening and how do I fix it?
回答1:
Don't mix scanf() with fgets() in the same code.
scanf("%d",&choice); does not consume all the line - it leaves the trailing '\n' for the later fgets() to consume as an empty line.
scanf() is difficult to use in a secure fashion.
来源：https://stackoverflow.com/questions/61642572/using-fgets-after-scanf