tokens

[deika]

what are tokens and what does strtok do?

[JosAH]

what are tokens and what does strtok do?

I'll move your question over to the C/C++ Forum section where it belongs.

kind regards,

Jos

[Studlyami]

strtok tells how you want to separate a string and where you want to store it.
Heres a basic example.

    FILE *f_ptr;  //points to an open text file
    f_ptr = fopen("MyText.txt", "rt"); //opens the text file

    if(f_ptr == NULL) //error opening file
        return;

    char * c_Ptr = NULL; // holds a temparay selection sections
    char c_Ptr1[1000] = {NULL}; //holds the entire line of text

    for(;fgets(c_Ptr1, 1000, f_ptr)!=NULL;) //grabs the next line of text
    {
        c_Ptr = strtok(c_Ptr1, ","); // first time to separate hold the location in the line
        while (c_Ptr != NULL)
        c_Ptr = strtok(NULL, ","); 
}

if the first line of text said "this is, the line of, text separated by a specific token"

the first time strtok c_Ptr = this is
2nd strtok c_Ptr = the line of
3rd strtok c_Ptr = text separated by a specific token

Then when it hits the for loop it grabs the next line in the text file until it find the end of file.

[Studlyami]

Wow my example is pretty ugly here is a much cleaner example fro www.cplusplus.c om

/* strtok example */
#include <stdio.h>
#include <string.h>

int main ()
{
  char str[] ="- This, a sample string.";
  char * pch;
  printf ("Splitting string \"%s\" into tokens:\n",str);
  pch = strtok (str," ,.-");
  while (pch != NULL)
  {
    printf ("%s\n",pch);
    pch = strtok (NULL, " ,.-");
  }
  return 0;
}

Output:


Splitting string "- This, a sample string." into tokens:
This
a
sample
string