strcpy導致線程1：信號SIGABRT

Question

我只是在做一些練習代碼，但我不知道這個頑固的線程1：

信號SIGABRT錯誤。

int main(){
    char diet[] = "vegan";

    printf("Because of health concerns, my diet is now %s.\n", diet);

    strcpy(diet, "whatever");

    printf("Before the health concerns, my diet was %s.\n", diet);


    return 0;
}

Answer 1

strlen（“ whatever”）> strlen（“ vegan”）=未定義的行為。

為什么您認為需要復制字符串。 您可以這樣做：

int main(){
    char *diet = "vegan";
    printf("Because of health concerns, my diet is now %s.\n", diet);
    diet = "whatever";
    printf("Before the health concerns, my diet was %s.\n", diet);
    return 0;
}

Answer 2

您需要分配更多的內存來解決此問題； 您不能在6個字節的空間中存儲9個字節-這會導致錯誤。

解

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

char *create(const char *src) { 
   char *ret = calloc(sizeof(char*) , strlen(src) + 1);
   strcpy(ret , src);
   return ret;
}

int main(){
   char *diet = create("Vegan");
   printf("Because of health concerns, my diet is now %s.\n", diet);
   free(diet); // always free it after using it or before changing it

   diet = create("whatever");
   printf("Before the health concerns, my diet was %s.\n", diet);
   free(diet);

   return 0;
}