c - getchar() 在尝试扫描输入时跳过第一个字符

Question

我正在尝试扫描来自终端的输入，并且正在尝试扫描初始空白，但程序只是跳过它。我之前在另一个程序中尝试过使用此方法，但它在我的新程序中不起作用。请帮助!!!

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

#define ADMIN_PASS "ABC123"
#define MAX_ARR_LEN 20
#define debug

void getinput(char inp[], int n);
void password(char passUser[]);

int main(void)
{      
    char passUser[MAX_ARR_LEN+1];
    int i=1;
    while (i==1)
    {
        password(passUser);
        printf("Try again?(1/0)>");
        scanf("%d",&i);
        if (i == 1)
        printf("\n");
    }
    return 0;
}

void getinput(char inp[], int n)
{
    scanf("%[^\n]c", &inp[n-1]);
    #ifdef debug
        printf("\nThe entered code in function>%s\n",inp);
        printf("The 1st character of entered code in function>%c\n",inp[0]);
    #endif
}

void password(char passUser[])
{
    char admin[MAX_ARR_LEN+1] = ADMIN_PASS;
    do
    {
        printf("\nPlease enter the Administrator password to Login:\n");
        getchar();
        getinput(passUser);
        #ifdef debug
            printf("\nThe input password in main is>%s\n", passUser);
            printf("The 1st character in main is>%c\n", passUser[0]);           
        #endif
        if (strcmp(passUser, admin) != 0)
        {
            printf("The password entered is incorrect, try again\n");
        }
    } while (!(strcmp(passUser, admin) == 0));   
}

Answer 1

您应该使用 fgets(inp, sizeof(ADMIN_PASS), stdin) 传递字符串，如下所示:

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

#define ADMIN_PASS "ABC123"
#define MAX_ARR_LEN 20
#define debug

void getinput(char * inp);
void password(char * passUser);

int main(void)
{
    char passUser[MAX_ARR_LEN+1];
    int i=1;
    while (i==1)
    {
        password(passUser);
        printf("Try again?(1/0)>");
        scanf("%d",&i);
        if (i == 1)
        printf("\n");
    }
    return 0;
}

void getinput(char * inp)
{
    fgets(inp, sizeof(ADMIN_PASS), stdin);
    #ifdef debug
        printf("\nThe entered code in function>%s\n",inp);
        printf("The 1st character of entered code in function>%c\n",inp[0]);
    #endif
}

void password(char * passUser)
{
    char admin[MAX_ARR_LEN+1] = ADMIN_PASS;
    do
    {
        printf("\nPlease enter the Administrator password to Login:\n");
        getinput(passUser);
        #ifdef debug
            printf("\nThe input password in main is>%s\n", passUser);
            printf("The 1st character in main is>%c\n", passUser[0]);
        #endif
        if (strcmp(passUser, admin) != 0)
        {
            printf("The password entered is incorrect, try again\n");
        }
    } while (!(strcmp(passUser, admin) == 0));
}

我删除了 getchar() 和函数 getinput() 的第二个参数，因为它们没有用。