Eval in C?
Hello again!
Is there such a thing as eval in C?
In my C-file I have this defined
#define doSomething (0x123456)
#define doSomethingElse (0x100efe2)
Then I will like to read an imput from a file an instead of writing the hexadecimal value I would like to write doSomethingElse, in that way my user will know what he7she is doing and would not need to memeorize the hexadecimal values?
Any tips?
/Steffi
Eval is not possible with C code. Though probably what you had seen was machine code "building" on runtime. I don't think that's something for beginners though...
"The Internet treats censorship as damage and routes around it." - John Gilmore
Well simple name=value type substitutions are relatively easy to implement with a simple look up table of sorts.
You start with say
int doSomethingElse = 0x100efe2;
If you then read say
doSomethingElse
from the file, you can use a table of names to find the corresponding symbol.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Well I know C is evil, but I have no idea what you mean by "Eval"?
Thinking laterally:
You could of course create a little file like this:
and run that through the C-preprocessor [e.g gcc -E myfile.p]Code:// myfile.p #define doSomething (0x123456) #define doSomethingElse (0x100efe2) #include myfile
--
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Eval is found in Perl and other scripting languages (I think -- I only know Perl). It is used to evaluate a string as if it were code.Originally Posted by cpjust
@steffi
Can you describe what you are trying to do?
It is too clear and so it is hard to see.
A dunce once searched for fire with a lighted lantern.
Had he known what fire was,
He could have cooked his rice much sooner.
> Well I know C is evil, but I have no idea what you mean by "Eval"?
Evaluate, ie evaluate a string as C code at runtime.
