How can I compile a file with different constants?

[Valentin Tihomirov]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example

char a[BYTE_SIZE];

where BYTE_SIZE is a constant defined in an external (.h?) file.

 

[osmium]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example

char a[BYTE_SIZE];

where BYTE_SIZE is a constant defined in an external (.h?) file.

Perhaps you want to know about the preprocessor? You can use #define and
control it with #if.

 

[Martin Ambuhl]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example

char a[BYTE_SIZE];

where BYTE_SIZE is a constant defined in an external (.h?) file.

Use CHAR_BIT from <limits.h>.
But note that the "size" of a byte as given by sizeof(char) is always 1.

 

[Ben Pfaff]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example
char a[BYTE_SIZE];
where BYTE_SIZE is a constant defined in an external (.h?) file.

Use CHAR_BIT from <limits.h>.
But note that the "size" of a byte as given by sizeof(char) is always 1.

I don't think you're answering the OP's question.

 

[Rouben Rostamian]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example

char a[BYTE_SIZE];

where BYTE_SIZE is a constant defined in an external (.h?) file.

If BYTE_SIZE is defined somewhere, well, there is not much you
can do about it. That's that.

If BYTE_SIZE is undefined, then see if your compiler supports a
-D flag. For instance, with gcc you may do:

gcc -DBYTE_SIZE=23 prog.c

 

[Dan Pop]

I have a .c file with a general code. It can be compiled with different
constants for different applications. For example

char a[BYTE_SIZE];

where BYTE_SIZE is a constant defined in an external (.h?) file.

If BYTE_SIZE is defined in a header file, all you have to do is to
include that header before using the BYTE_SIZE macro.

Most compilers also allow you to define macros at compile time, e.g.
via compiler command line options.

Dan