Thread: compare strings not working

I am somewhat new to C programming, but this looks like it should work. I am using MS VS .Net 2002. When I put my mouse over the variable, the strings match up, but when I compare them, the comparison does not equal each other. What I do here is parse a string, then I need to compare it. so if the string is "123 W Main St". It seems to parse ok, but when i come to the "W", I need to compare it with "W" and it does not work.

Code:

char * Grab_String(char* string, int length)
{
	char *ip;
	int i = 0;

	ip = (char *) malloc(length*sizeof(char *));
	while (i < length)
	{
		ip[i] = string[i];
		i = i++;
	}
	ip[i] = '\0';

	return ip;
}


char *ParseDelimiter (char *addr_string, char delimiter)
{
	char *field;
	char hold;
	int seperator;
	int str_len;
	int i = 0;
	int x=0;
	bool ok=false;

	str_len = strlen(addr_string);
	while (i <= str_len)
	{
		if (addr_string[i] == delimiter)
			break;
		i = i++;
	}	

	field = Grab_String(addr_string, i);

	if ("W"==field)   //////HERE IS THE CODE THAT DOES NOT WORK
	{
		ok=true;
	}

	return field;
}

Thanks for helping.

George

this is something terribly wrong with this function, but i dont know what it is. If you see, where I commented out the address, if I uncomment it, the function works fine. The other strange thing is that when i am in the dubugger, the variable returned will be the correct one, but the compare strings does not work. If I uncomment, and use the hard code the strings compare fine. Please help, my head hurts from banging it on the desk.

Code:

char * left(char * string, int length) 
{ 
	char *ip;
	int i = 0;

	ip = (char *) malloc((length*sizeof(char)));
	while (i < length)
	{
		ip[i] = string[i];
		i++;
	}
	ip[i] = '0';

	//ip = "2406 W OCEAN FRONT ST";

	return ip;
}

You should pass a previously allocated buffer to your function, because returning local stack data is dangerous and heap data must be free()'ed. You can assume your strings are null-terminated and remove the length parameter probably. Your implementation will end up looking very similar to strcpy (is this what your function intends?), which you will notice also takes a destination and source buffer.