C - split string into an array of strings

c, c-strings

Solution

Since you've already looked into `strtok` just continue down the same path and split your string using space (`' '`) as a delimiter, then use something as `realloc` to increase the size of the array containing the elements to be passed to `execvp`.

See the below example, but keep in mind that `strtok` will modify the string passed to it. If you don't want this to happen you are required to make a copy of the original string, using `strcpy` or similar function.

char    str[]= "ls -l";
char ** res  = NULL;
char *  p    = strtok (str, " ");
int n_spaces = 0, i;


/* split string and append tokens to 'res' */

while (p) {
  res = realloc (res, sizeof (char*) * ++n_spaces);

  if (res == NULL)
    exit (-1); /* memory allocation failed */

  res[n_spaces-1] = p;

  p = strtok (NULL, " ");
}

/* realloc one extra element for the last NULL */

res = realloc (res, sizeof (char*) * (n_spaces+1));
res[n_spaces] = 0;

/* print the result */

for (i = 0; i < (n_spaces+1); ++i)
  printf ("res[%d] = %s\n", i, res[i]);

/* free the memory allocated */

free (res);

res[0] = ls
res[1] = -l
res[2] = (null)

Problem

I'm not completely sure how to do this in C: ``` char* curToken = strtok(string, ";"); //curToken = "ls -l" we will say //I need a array of strings containing "ls", "-l", and NULL for execvp() ``` How would I go about doing this?

Original source