这是什么情况，有哪位大神指点一下

[Tenacious0]

[Tenacious0]

#include<stdio.h>
#include<string.h>

int main(void) {
FILE *file;
char name[123];
char password[123];
char name_tmp[123];
char password_tmp[123];
char name_pass;
char *ret;

file = fopen("D:\\liu\\lx.txt","r+");
if (file == NULL) {
printf("文件打开失败！");
return 1;
}

while(1) {
printf("请输入用户名：");
scanf("%s",name);
printf("请输入密码：");
scanf("%s",password);

while(1) {
ret = fgets(name_pass,sizeof(name_pass),file);
if (ret==NULL) { //判断文件有没有读取成功
break;
}

sscanf(name_pass,"%s %s",name_tmp,password_tmp);

if((strcmp(name,name_tmp) == 0) && strcmp(password,password_tmp) == 0) {
break;
} else {
printf("用户名或密码错误！");
system("pause");
system("cls");
}
}
}
return 0;


下面是编译错误代码
aaa.c: In function 'main':
aaa.c:26:4: warning: passing argument 1 of 'fgets' makes pointer from integer without a cast [enabled by default]
In file included from aaa.c:1:0:
c:\mingw\bin\../lib/gcc/mingw32/4.7.1/../../../../include/stdio.h:354:39: note: expected 'char *' but argument is of type 'char'
aaa.c:31:4: warning: passing argument 1 of 'sscanf' makes pointer from integer without a cast [enabled by default]
In file included from aaa.c:1:0:
c:\mingw\bin\../lib/gcc/mingw32/4.7.1/../../../../include/stdio.h:348:37: note: expected 'const char *' but argument is of type 'char'
aaa.c:42:2: error: expected declaration or statement at end of input

[自信男孩]

能否把代码直接贴出来，测试现象可以截图嘛

[Tenacious0]

好的谢谢。在问一下，fscanf和sscanf的语法有什么区别

[zangfong]

你的第12行

char name_pass;

应该是想定义成类似如下的字符数组的吧

    char name_pass[256];

这么修改，再加上头文件

#include<stdlib.h>

至少你贴出来的代码可以运行了，如下

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

int main(void)
{
    FILE *file;
    char name[123];
    char password[123];
    char name_tmp[123];
    char password_tmp[123];
    char name_pass[256];
    char *ret;

    file = fopen("D:\\liu\\lx.txt","r+");
    if (file == NULL)
    {
        printf("文件打开失败！");
        return 1;
    }

    while(1)
    {
        printf("请输入用户名：");
        scanf("%s",name);
        printf("请输入密码：");
        scanf("%s",password);

        while(1)
        {
            ret = fgets(name_pass,sizeof(name_pass),file);
            if (ret==NULL)      //判断文件有没有读取成功
            {
                break;
            }

            sscanf(name_pass,"%s %s",name_tmp,password_tmp);

            if((strcmp(name,name_tmp) == 0) && strcmp(password,password_tmp) == 0)
            {
                break;
            }
            else
            {
                printf("用户名或密码错误！");
                system("pause");
                system("cls");
            }
        }
    }
    return 0;
}

[zangfong]

sscanf 从指定字符串输入，而fscanf 是从文件输入，下面是fscanf的应用

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

int main(void)
{
    FILE *file;
    char name[123];
    char password[123];
    char name_tmp[123];
    char password_tmp[123];
    char name_pass[256];
    char *ret;
    int login_success = 0;

    file = fopen("D:\\liu\\lx.txt","r+");
    if (file == NULL)
    {
        printf("文件打开失败！");
        return 1;
    }

    while(1)
    {
        printf("请输入用户名：");
        scanf("%s",name);
        printf("请输入密码：");
        scanf("%s",password);

        while(1)
        {
//            ret = fgets(name_pass,sizeof(name_pass),file);
//            if (ret==NULL)      //判断文件有没有读取成功
//            {
//                break;
//            }
//
//            sscanf(name_pass,"%s %s",name_tmp,password_tmp);

            fscanf(file,"%s %s",name_tmp,password_tmp);

            if((strcmp(name,name_tmp) == 0) && strcmp(password,password_tmp) == 0)
            {
                printf("登陆成功！\n");
                break;
            }
            else
            {
                printf("用户名或密码错误！");
                system("pause");
                system("cls");
                break;
            }
        }
    }
    fclose(file);
    return 0;
}