Splitting a string?

[motionman95]

Hello! I have a question. I'm trying to take this string:

howOld:20

and split it, right at the ":", so I get an Array like this:

myArray[1] = {"howOld","20"}

How difficult is this to do, and how should I go about doing it? I'm reading that string from a settings file.

Thanks in advance!

[sean]

Look into the strtok() function in string.h. You specify a string and a delimiter (in your case the ':') every time you call it, and each time you call it, it will return a pointer to the next piece of the string. When there are no more pieces, it returns NULL.

[vart]

another way - is using sscanf - which will not modify original buffer, but you will need to provide the additional storage for the parsed substrings

char name[20];
char val[11];
const char* str="howOld:20";
if(sscanf(str,"%19[^:]:%10[^\n]", name, val) == 2)
{
   /* parsed ok*/
}

[Maz]

there is lot of solutions. Here was another thread with similar question, and i suggested these. 1. Loop through the array, char by char, and replace each : with \0. And store start address for next string in ptr array. 2. I wrote c version of php's explode, and it is introduced in my blog. It should do what you want. Link is in my signature.

[motionman95]

Before I read either of your posts (I had left the house) a little mental brainstorming helped me to come up with this:

char name[20], value[20];

static int parseSetting(char* myString)
{
        int i, array[1], i2 = 0, len = strlen(myString);
	bool sep = false;
	
	for(i = 0; i<len; i++){
	    if (myString[i] != ':') {
		    if(!sep){
		        name[i] = myString[i];
			} else {
			    value[i2] = myString[i];
				i2++;
			}
		} else {
		    sep = true;
		}
	}
	
	name[i] = '\0';
	value[i] = '\0';
	
	array[0] = name;
	array[1] = value;
	
	return array;
}

parseSetting("howOld:20");

The bad thing is that it gives these warnings:

In function 'parseSetting':
warning: assignment makes integer from pointer without a cast
warning: assignment makes integer from pointer without a cast
warning: return makes integer from pointer without a cast
warning: function returns address of local variable

What's wrong?

[sean]

name is a character array, and when you use just the array name, the compiler evaluates it as a pointer to the first element in the array. So you're assigning a pointer (&name[0]) to an integer (array[0]). If you want to get a number out of a string you should use atoi(), or sscanf().

Another problem I see is that you declare an array as "int array[1]" - which only has one element. If you declare "int array[2]" you can refer to the two elements as array[0] and array[1].

[motionman95]

name is a character array, and when you use just the array name, the compiler evaluates it as a pointer to the first element in the array. So you're assigning a pointer (&name[0]) to an integer (array[0]). If you want to get a number out of a string you should use atoi(), or sscanf().

Another problem I see is that you declare an array as "int array[1]" - which only has one element. If you declare "int array[2]" you can refer to the two elements as array[0] and array[1].

Hmm...should I do a for loop instead of a plain assignment?

[sean]

Unless you're doing more than 2 or 3 elements I hardly see the point. It wouldn't fix any of your errors.

[motionman95]

array[0] = name;
array[1] = value;

I'm just asking what I should do to get this to work. The 'value' variable isn't always going to be a number.

[sean]

Then I would store it as a string. Maybe you should have an array of char pointers.

[motionman95]

Huh? I'm not sure I'm catching you. Store what as a string?

[King Mir]

If it doesn't store integers, why is array define an array of ints?

you can declare an array of two char pointer like this:

char *charptrs[2];

This will require you to make sure that the char pointers are properly managed and freed, if need be. The easiest way is to malloc memory, and copy the strings over.

[sean]

If the data can be anything, just store it in the format that you originally recieved it in: a string. Since you're splitting it into parts, you need an array of strings (or just two separate strings). The way you can do that is

char * strings[2];
strings[0] = &first_string[0]; // You set the pointer to the address of the first element
strings[1] = second_string; // You can refer to an array by name too, and you get the address of the first element