Q:

Different sizeof(long) values in W7 and Linux Mint

IDE: Code::Blocks 13.12
Compiler: GNU GCC
Application type: console application
Language: C
Platforms: W7 and Linux Mint
I wrote a compiler and interpreter for a self defined language, I made executables for Windows and Linux. The compiler - obviously - generates a code file that is read by the interpreter. I want to use the compiled file both on Windows and Linux. So, a file created with the Windows compiler must be readable by the Linux interpreter and vice versa.
I can't get the compatibility to work. I found that in Windows, the sizeof(long)=4 and in Linux, sizeof(long)=8. As the compiler will write long integers to the output file I think the difference in size is (part of) the problems I have.
I checked this forum, but similar problems are mostly about casting and writing platform independent C++ code. I also found some suggestions about using (u)intptr_t but these are also pointer related.
Maybe the quickest solution is to use type int rather than long in Linux, but then I would have different sourcecode for both platforms.
Is there another way to handle this issue?

A:

Consider using int32_t for a 32 bit 2's complement signed integral type, and int64_t for a 64 bit 2's complement signed integral type.
Note that a compiler doesn't have to support these types, but if it does then they must be as I describe.
An int in C can be as small as -32767 to +32767. A long must be at least 32 bit. MSVC maintains a long as 32 bit on 64 bit systems (it uses the LLP64 model). The C standard does not place an upper limit on the sizes. This flexibility allows optimal C compilation on a variety of platforms.

