从主数组中的函数存储令牌（strtok）

Question

I'm trying to make a function to split a sentence in words and store the words into an array of strings. If I use a global variable it works, the strings are stored nice and the job is done, however, when I try to pass an array defined in main it won't work.

void split(char sentence[], char *words[]){
  unsigned char n= 0;
  const char delim n= " ";
  char clone[strlen(sentence)];
  strcpy(clone, sentence);

  char *token;
  token= strtok(clone, delim);

  while(token != NULL){
    words[n++]= token;
    token= strtok(NULL, delim);
  }
  words[n]= NULL; //Needed for future usage of the array;
}

int main(){
  char *sentenceFromMain;
  sentenceFromMain= "A BB CCC DDDD";

  char *wordList[nrOfWords+1]; //I do have another function that counts words

  split(sentenceFromMain, wordList);
  exit(0);
}

If I do in the function, for example, words[0]= "A"; it works. Is token return a pointer? How should I get only whats stored in it? I tried multiple ways to do this, none of them worked well. Every response is welcomed!

Answer 1

The problem here is that strtok returns pointers into the string it tokenizes. The pointers you get will be pointers into the clone array, which is local inside the split function. Once the split function returns the pointers will no longer be valid.

One possible way to solve this problem is to not have a local clone array, but have it externally outside the function, and pass it in as the first argument and use that argument in the call to strtok .