read a constant from a file

[Kais3r]

Hi everyone,

I'm trying to read a settings file for a program i'm working on. This settings file is something like this:

option1=asdf
option2=5
option3=CONSTANT_X

where CONSTANT_X is a string too.

There is no problem about reading the numbers or strings from the program but, how can i read CONSTANT_X and use it as a constant in my program?
what i mean is to use it as:

int number=CONSTANT_X; (for example)

how can i interpret the constant from a string?? I don't know if i'm explaining it right

thanks!!

[claudiu]

So get the value and put it in a const variable that is declared but not initialized until you initialize it with that value.

To get the value use strtol() assuming it's an integer value.

[Kais3r]

no, you are not getting the value from the file, you are getting the name of the constant, and you want to use it.


Imagine you would have CONSTANT_X defined in your whatever_you_are_doing and you are preparing a demo or something, and you need to use some of this constants that you have defined in your program in that file.

I'm doing some stuff with a DDS distribution, a communication protocol, and it has a lot of predefined constants. What i want to do is some kind of settings for one kind of entity and some of this parameters must be initialized with constants, so in the settings file i must use the constant's name.

Imagine a Reliability parameter, it can be defined as "REALIABLE" or "BEST_EFFORT" so i need my program to read the "RELIABLE" string or the "BEST_EFFORT" string and be able of interpret them as the predefined constant

I hope i have explained myself better

[Kais3r]

well, the post is not needed any more it can be closed

The answer is that reflection is not implemented in C, so it can't be done that way

[Salem]

Reading a constant name from a file - Dev Shed