我在比较用户输入的用户名和密码。被比较的字符串是从文件中读入的。不管出于什么原因,它都是在适当地比较用户名,而不是密码。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
const int MAX_SIZE = 100;
int main()
{
FILE *fp;
char *filename = "userdata.txt";
char arr[100][MAX_SIZE];
//open for writing
fp = fopen(filename, "r");
//verify open
if(fp == NULL)
{
printf("%s does not exist", filename);
return 0;
}
int index = 0;
//read file into array
while(fgets(arr[index], MAX_SIZE, fp) != NULL)
{
index++;
}
//username input
char username[100];
printf("Username: ");
scanf("%s", username);
//password input
char password[100];
printf("Password: ");
scanf("%s", password);
int check1 = 0;
int check2 = 0;
int x;
for (int i = 0 ; i<index ; i++)
{
char *token = strtok(arr[i], " ");
while (token != NULL)
{
x = strcmp(token,username);
printf("%d\n",x);
printf("%s %s\n",token,username);
if(!strcmp(token,username))
{
check1 = 1;
}
token = strtok(NULL, " ");
x = strcmp(token,username);
printf("%d\n",x);
printf("%s %s\n",token,password);
if(!strcmp(token,username))
{
check2 = 1;
}
token = strtok(NULL, " ");
if(check1&&check2)
{
printf("The amount is: %s\n",token);
return 0;
}
token = strtok(NULL, " ");
check1=0;
check2=0;
}
}
printf("Username/Password mismatch!!!\n");
return 0;
}
控制台输出:
Username: user1
Password: password1
0
user1 user1
-5
password1 password1
1
user2 user1
-5
password2 password1
2
user3 user1
-5
password3 password1
3
user4 user1
-5
password4 password1
4
user5 user1
-5
password5 password1
5
user6 user1
-5
password6 password1
Username/Password mismatch!!!
1条答案
按热度按时间5sxhfpxr1#
当
fgets
读入一行文本时,它也会读取并存储该行末尾的换行符。这意味着,当您使用
strtok
拆分字符串并使用" "
作为后缀时,读入的密码包括换行符,而通过scanf
读取的用户密码(带有%s
说明符)不包括换行符,从而导致不匹配。您可以通过在指定给
strtok
的分隔符集中包含换行符来解决这个问题。另外,对
strcmp
的第二组调用是检查用户名而不是密码。因此,与此相反:你想要这个: