Thread: string tok

Repeat calls to strtok should be called with NULL instead of the string.

The strtok() function is used to isolate sequential tokens in a null-ter-
minated string, str. These tokens are separated in the string by at
least one of the characters in sep. The first time that strtok() is
called, str should be specified; subsequent calls, wishing to obtain fur-
ther tokens from the same string, should pass a null pointer instead.
The separator string, sep, must be supplied each time, and may change
between calls.

See the man page


Quzah.

I could have sworn he had the array name there when I looked for it. Oh well.

The delimiter doesn't have to be mutable. In fact, it shouldn't be modified at all by strtok at all. Since arrays degrade to pointers to their type when passed to functions anyway, this would serve no purpose (since it isn't modified by the function).

I do wonder however, what he's passing to this function as an argument. He has down that it's an array of ints.

Code:

#include<string.h>
#include<stdlib.h>
#include<stdio.h>

int freqInput(int *array)
{
   
    /* declaration of variables*/
    char *delim = " ";
    char chInput[255];
    char *p = chInput;
    int count = 0;
    
    /* call to user input*/
    fgets(chInput, 255, stdin);

    p = strtok(chInput, delim);

   /* get the rest of the input tokenized until
      there is none left then convert it to a
      int and place it each element of the array*/

    while(p != NULL)
    {
      array[count++] = (int) strtol(p, NULL, 10);
      p = strtok(NULL, delim);
    }
    /* pass it back to options.c*/

    return count;
}

int main( void )
{
    int array[10] = {0};
    int f, c;
    
    printf( "> " );
    fflush( stdout );
    f = freqInput( array );
    
    for( c = 0; c < f && c < sizeof array / sizeof array[0]; c++ )
        printf( "array[ &#37;d ] is %d\n", c, array[ c ] );
    
    return 0;
}

Quick test case shows it working fine for me. I suspect they're doing a few things wrong:

1 - Not initializing the array they're passing it.
2 - Not filling it completely.
3 - Printing the entire array, not only the filled cells.


Quzah.