Question

我试图在linux系统和gcc-4.7编译器上获取用户名和密码，如下所示：

#include "stdio.h"
#include "stdlib.h"
#include <termios.h>
#include <unistd.h>

void getuserdata(char *passwd)
{
    struct termios term, term_orig;
    tcgetattr(STDIN_FILENO, &term);
    term_orig = term;
    term.c_lflag &= ~ECHO;
    tcsetattr(STDIN_FILENO, TCSANOW, &term);

    scanf("%s", passwd);
    /* Remember to set back, or your commands won't echo! */
    tcsetattr(STDIN_FILENO, TCSANOW, &term_orig);

}

int main()
{
    char *password, *username;
    printf("Enter username: ");
        scanf("%s", username);
        fflush(stdin); 
    printf("\n");

    printf("\nEnter password: ");
    getuserdata(password);

    printf("Entered username is:%s\n", username);
    printf("Entered password is:%s\n", password);
    return 0;
}

和预期的行为如下：

Enter username: test 
Enter password:
Entered username is: test 
Entered password is: xxxx

但它不起作用，并将null作为用户名或密码。

伙计我哪里错了？

非常感谢任何帮助。

感谢。

Answer 1

您没有为username和password分配内存。

char *password, *username;
username = malloc(50);
printf("Enter username: ");
    scanf("%49s", username);

printf("\n");

printf("\nEnter password: ");
password = malloc(50);
getuserdata(password);

scanf函数的输入给出了意想不到的结果

1 个答案: