c -正确使用带错置指针的strtok指向string

Question

我看到了很多带有数组的strtok示例，但没有指向数组的指针。我随便拿了一个，试着猜测它应该是如何工作的。它不是。为什么这会导致总线错误?

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
int main () {
char *str = malloc(16);
memset(str, '', 16);
str = "This - is - foo";
const char s[2] = "-";
char *token;

/* get the first token */
token = strtok(str, s);

/* walk through other tokens */
while( token != NULL ) {
printf( " %sn", token );

token = strtok(NULL, s);
}

return(0);
}

Answer 1

char *str = malloc(16); // you allocate memory
memset(str, '', 16);  // you set it to zero
str = "This - is - foo";// you loose the reference to it assigning the pointer with the string literal reference
// now str references string literal
// as a bonus you got the memory leak as well

你能做什么?:

char *str = malloc(16);
strcpy(str, "This - is - foo");

或简单

char str[] = "This - is - foo";

或

char *str = strdup("This - is - foo");