c - strcmp 给出段错误

Question

这个问题在这里已经有了答案:





Crash or "segmentation fault" when data is copied/scanned/read to an uninitialized pointer

(5 个回答)


5年前关闭。




这是我给出段错误的代码

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

int main(void) {
    char *get;
    scanf("%s", get);
    int k = strcmp("sachin", get);
    printf("%d", k);
}

谢谢你的帮助;

Answer 1

char *get;

上面的语句定义了 get成为指向字符的指针。它可以存储类型为 char 的对象的地址。 ，不是字符本身。问题在于 scanf和 strcmp称呼。您需要定义一个字符数组来存储输入字符串。

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

int main(void) {
    // assuming max string length 40
    // +1 for the terminating null byte added by scanf

    char get[40+1];

    // "%40s" means write at most 40 characters
    // into the buffer get and then add the null byte
    // at the end. This is to guard against buffer overrun by
    // scanf in case the input string is too large for get to store

    scanf("%40s", get);
    int k = strcmp("sachin", get);
    printf("%d", k);

    return 0;
}