Segmentation Fault when using strtok_r

Question

Can anyone explain why I am getting segmentation fault in the following example?

#include 
#include 

int main(void) {
  char          


        

Answer 1

A bunch of things wrong:

1. hello points to a string literal, which must be treated as immutable. (It could live in read-only memory.) Since strtok_r mutates its argument string, you can't use hello with it.

2. You call strtok_r only once and don't initialize your tokens array to point to anything.

Try this:

#include 
#include 

int main(void) {
  char hello[] = "Hello World, Let me live.";
  char *p = hello;
  char *tokens[50];
  int i = 0;

  while (i < 50) {
     tokens[i] = strtok_r(p, " ,", &p);
     if (tokens[i] == NULL) {
        break;
     }
     i++;
  }

  i = 0;
  while (i < 5) {
    printf("%s\n", tokens[i++]);
  }

  return 0;
}