I am trying to write a function to take a char and return a string as
follows: the user will enter say:  4 + 3  and I need to turn the +
into "ADD" to store it in a structure element.

struct math_operation
{
   int operand1;
   char *operation; // this is where I need the + to be ADD
   int operand2;
} message;

I've got the extraction and assignment of the two numbers working
fine.

I've got the "+" char extracted from the args:
char *tempOp;
tempOp = argv[2];

Now I need a function to convert the "+" to "ADD" (and "-" to "SUB",
"*" to "MUL" and "/" to "DIV") then put that string into its struct
member
message.operation = ??

The attempts I've made so far have just not worked. I think I've got a
pointer problem. So, what is the correct way to have a function take
the char + - * or / and return the respective string ADD SUB MUL or
DIV?

Thank you!
-David

hi - 
ultimately your parser will need to be more complicated than what you
have suggested here because getting the second character of an array
like this:
char *tempOp; 
tempOp = argv[2]; 

may not work unless the input has been very strictly assembled - for
example:

if you use 4 + 3 it will work - but if the user types by accident: 4+3
it will not work - or consider 4+ 3 - etc...

anyway, here is one way of doing what you are asking for:

C does not have an "associate a character with a string" or a "map a
string to a string" native to the language - so you have to do this
manually - here is one way to do it:

char * LookupOperand(char X)
( 
    char *szRet = "";

    switch (X)
    {
        case '-':
            szRet = "SUB";
            break;
        case '+':
            szRet = "ADD";
            break;
        case '*':
            szRet = "MUL";
            break;
        case '/':
            szRet = "DIV";
            break;

        default:
            // error condition
            // do something here
            break;
    }
    return(szRet);
}

now you can just call this with your character - so, it would look
something like this:

    char *Operand;

    Operand = LookupOperand(argv[2][0]);

    // or you could do this
    char *tempOp;

    tempOp = argv[2];
    Operand = LookupOperand(*tempOp);

    // these two operations are the same thing.

good luck.
Dan