Question

I’m reading a string with space as a delimiter by using the strtok function.

My code looks like this:

char * pch = strtok (text," ");
int i = 0;
while (pch != NULL)
{
  if (i == 0)
     strcpy(name, pch);
  else
     others[i - 1] = pch;
  pch = strtok (NULL, " ");
}

The string looks like this: TCP 1 2 3 4, and name is of char* type that I receive in my function.

I wish to assign name to be TCP (i.e. first piece before the first delimiter), but because the pch pointer proceeds, the name variable changes when pch changes. How can I assign the pch pointer value to name without it being changed when the pointer changes?

Answer 1

You never increment i so every loop ends up copying the latest value of pch into name.

You could fix it by incrementing i for each iteration of the loop:

char * pch = strtok (text," ");
int i = 0;
while (pch != NULL)
{
  if (i++ == 0) // ++ is the only change from your code
     strcpy(name, pch);
  else
     others[i - 1] = pch;
  pch = strtok (NULL, " ");
}