from a text file to a structure ?

**Intenz** · 12-29-2003

So far i have written a program that reads a config file which is written in the form of:

Code:

// settings.cfg
// comment
item "value1 value2"
item2 value

The program assignes the the following:
item to char szVar[20]
values to char szVal[20] - (szVal is everything between the quotes or the 1st value if there arnt any quotes)

Now for the second part of the program i would like to assign each value to a value in a structure. the variables in the structure have the same name as the item in the config file. this is what my structure looks like at the moment:

Code:

typedef struct _SETTINGS {
  string          item;
  string          item2;
} SETTINGS;

i could do it this way:

Code:

if (szVar == item) {
  // assigne value to settings.item
}
else if (szVar == item2) {
  // assigne value to settings.item2
}

But it looks too messy when you have about 10-15 items and i dont think its very good practice. i tried using a switch case statment but then realised that they only take intagers

Is there a way that you can make a variable name the value of szVar
say.. szVar = item; can i make a variable with the name of what is held in szVar which is item. this is the only other way i can think of doing this.
if anyone can suggest anyother way to do this that would be great.

Thanks for taking your time to help me out

**erikj** · 12-29-2003

if you are using c++, stl map is perfect for you. It lets you assign values to keys. Here is a small example.

Code:

#include <iostream>
#include <map>
#include <string>

using namespace std;

int main()
{
	map<string,string> settings;
	
	settings["fullscreen"]="yes";
	settings["invert mouse"]="no"; 

	map<string,string>::const_iterator i;
	
	for(i=settings.begin();i!=settings.end();i++)
		cout<<i->first<<"="<<i->second<<endl;
	return 0;
}

**Hammer** · 12-29-2003

>>if you are using c++
Although the code in the OPs post does reference a "string" object, we'll have to assume for now that this is a C program, as they've posted on the C forum. Maybe the OP can clarify?!

Anyways, here's one way to achieve the goal. Normally I wouldn't give you a complete code answer, but I think it'll be easy than trying to explain what I'm thinking!

Code:

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

struct Option
{
  const char  *Name;
  int   Value;
};

int FindOptionIndex(struct Option *OptionsTable, int Length, const char *Criteria)
{
  int i;
  
  for (i = 0; i < Length; i++)
  {
    if (strcmp(OptionsTable[i].Name, Criteria) == 0)
      return i;
  }
  printf ("Invalid option: >%s<\n", Criteria);  
  return -1;
}

int main(void)
{
  struct Option myOptions[2] = {
    {"item1", -1},
    {"item2", -1}
  };
  char SimulatedInput[] = "item2";
  int Index;
  int i;
  
  if ((Index = FindOptionIndex(myOptions, sizeof(myOptions)/sizeof(*myOptions), SimulatedInput)) != -1)
  {
    myOptions[Index].Value = 99;
  }
  
  for (i = 0; i < sizeof(myOptions)/sizeof(*myOptions); i++)
  {
    printf ("%s = %d\n", myOptions[i].Name, myOptions[i].Value);
  }
  
    
  return(0);
}

The "struct Option" contains the information for a single option, "myOptions" is an array of these. In main, we initialise the array to have names and default values.

The FindOptionIndex() function searches the array for an entry with a Name element that matches the input criteria. If no match is found, -1 is returned. The code in main() calls this function to determine the index location of a particular option, then sets the appropriate value, in this case to a hard coded value of 99.

In case you don't recognise it, this piece of code:
sizeof(myOptions)/sizeof(*myOptions)
... simply works out the count of elements in the myOptions array, which equates to 2 in this code.

**Intenz** · 12-30-2003

thanks a lot for the help Hammer i am at the moment trying to implement it into the program now. Im just trying to understand how this code works as im still fairly new to the C language but if i have ny more trouble i know where to ask. thanks again

Thread: from a text file to a structure ?

Thread Tools

Search Thread

Display

from a text file to a structure ?

Similar Threads

Newbie homework help

Possible circular definition with singleton objects

Ok, Structs, I need help I am not familiar with them

System

Moving to the next structure array