[英]Input from scanf function giving unexpected result
我試圖在Linux系統和gcc-4.7編譯器上獲取用於身份驗證的用戶名和密碼,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;
}
預期的行為如下:
Enter username: test
Enter password:
Entered username is: test
Entered password is: xxxx
但是它不起作用,並且將null用作用戶名或密碼。
伙計們,我要去哪里錯了?
任何幫助將不勝感激。
謝謝。
您沒有為username
和password
分配內存。
char *password, *username;
username = malloc(50);
printf("Enter username: ");
scanf("%49s", username);
printf("\n");
printf("\nEnter password: ");
password = malloc(50);
getuserdata(password);
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