int value passed to function

hey guys
this is probably an easy question to answer, but i just dont get it.

i have a main method where i call a function parse: something like that:

Code:

---

int main()
{
char *newargv[MAXITEM];
int size;
parse(newargv, size);
printf("argvsize = %i\n", newargvSize);
}

int parse(char *newargv[], int newargvSize)
{
newargvSize = 0;

// loop where values are assigned to the newargv array and the size is increaded
// newargv[newargvSize] = some string;
// newargvSize++;

printf("newargvSize: %i\n", newargvSize);
}

---

now the printf statement in my parse method outputs the correct value, where as my printf after the function call returns some random value (an address i guess). what would i have to do to get the same value as in my function. i tried to work with pointers and stuff, but couldn't figure it out yet! :(

any help appreciated,
thx

You need to pass a pointer.

This is a call by value.

The local copy of newargvSize is lost after going out of the function.

Also, your int function doesnt return anything. You might want to return newargvSize to a variable inside main. That should work if you dont want to use pointers.

Code:

---

int parse(char *newargv[], int newargvSize)
{
newargvSize = 0;

// loop where values are assigned to the newargv array and the size is increaded
// newargv[newargvSize] = some string;
// newargvSize++;

printf("newargvSize: %i\n", newargvSize);
}

---

Won't this perform an 'infinite' loop?

thanks for this fast reply!

yeah i'm returning a different value already, because i call another function in my parse function, forgot to mention that.

i tried to do it with pointers. i just don't get it i guess. heres what i had:

Code:

---

// main method
int newargvSize;
returnValue = parse(newargv, &newargvSize);

// parse method
int parse(char *newargv[], int *newargvSize)
{
newargvSize = 0;
newargv[newargvSize] = some string; // this results into the following error: array subscript is not an integer
newargvSize++;
}

---

so i created a new int size = 0;
used that in the array -> newargv[size] = some string; and tried to assign size to newargvSize, but that didnt work either. What am i doing wrong here? i have a feeling its not much, but i have no clue right now :(

well here is my whole parse method, to make it a little easier to understand i guess:

Code:

---

int parse(char *newargv[], int *newargvSize)
{
    char word[STORAGE];
    int returnValue = 0;
    newargvSize = 0;

    //int size = 0;

    for (;;)
    {
        returnValue = getword(word);

        //printf("pointer: %i\n", *newargvSize);

        if (returnValue == 0 || returnValue == -1)
        {
            newargv[newargvSize] = NULL;
            break;
        } else
        {
            // copy the word to the array because it will be overwritten
            // each time the loop is run again
            newargv[newargvSize] = (char*) malloc(strlen(word) + 1);
            strcpy(newargv[newargvSize], word);
            newargvSize++;
        }
    }

  // newargvSize = *size;

    //printf("size: %i\n", size);
    printf("newargvSize: %i\n", newargvSize);
    //printf("pointer: %i\n", *newargvSize);

    return returnValue;
}

---

Code:

---

int main()
{
char *newargv[MAXITEM];
int size;
printf("argvsize = %i\n", newargvSize = parse(newargv, size););
}

---

hmm.. thx, but i'm not returning the size (i can't) isn't that what your code snippet does?

the way i have my function now with the int pointer, is that how its supposed to be?
how do i use my int value in the array then?

newargv[newargvSize] = (char*) malloc(strlen(word) + 1);

this doesnt work anymore as a pointer. always get the error message -> array subscript is not an integer

what am i missing? :s

Yep, you're nearly there!

Code:

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newargv[newargvSize] = (char*) malloc(strlen(word) + 1);

---

Quote:

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Originally Posted by search

always get the error message -> array subscript is not an integer

---

Quite right, it is not an integer. It's a pointer, i.e. an address. You need to dereference the pointer. The dereferencing operator in C is *, and you need to use it whenever you want to access the value pointed to. So you should access the array like:

Code:

---

newargv[*newargvSize] = (char*) malloc(strlen(word) + 1);

---

Assign to newargvSize in parse like

Code:

---

*size = 0;

---

The rest of it looks correct, if you can't return the size.

Code:

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int parse(char *newargv[], int *newargvSize)

---

Code:

---

// main method
int newargvSize;
returnValue = parse(newargv, &newargvSize);

printf("newargvSize = %i", newargvSize); // no * needed here, newargvSize is not a pointer

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