The difference between a program in C++ developed under Windows and Linux

Question

What's the difference between a program developed in C++ under Windows and Linux?

Why can't a program developed under Windows in C++ be used under Linux?

Answer 1

• Windows and Linux use different container formats to hold the executable code (PE vs ELF).
• Windows and Linux have completely different APIs (except for trivial programs that only use the CRT and STL)
• Windows and Linux have a completely different directory structure

You could write a program that can use either set of APIs (for example, using Qt), and that can handle either directory structure, but you still won't be able to run the same file on both operating systems because of the differing container formats.

This can be solved by using Wine.

Answer 2

In a nutshell,

• Windows runs PE format executables
• Linux runs ELF format executables

Furthermore, even if there were a tool to convert between PE and ELF, the program instructions necessary to interface with the operating system are completely different between Windows and Linux. Only the most restricted computation-only code (that only does calculations and doesn't interact with the operating system at all) could be ported between systems without special action. However, this is rarely done.

I believe some versions of Linux allow you to directly load device drivers designed for Windows without recompiling. However, this is an extremely special purpose application and the technique is not generally used.