Difference between C under Windows and C under UNIX [closed]

Question

Does the 'power' of the C language change with the OS under which it is used ? What exactly is the difference , from a programmer's point of view ?

PS : I want to dive deep into 'C' (Advanced C) and have an affinity towards C under UNIX . Is it better than C under Windows ? Please also comment on creating applications in each environment .

Answer 1

I have listed down into several criteria:

• The libraries used to get anything platform-specific done are different.
• Unix world typically will use POSIX syscalls to do system stuff, like IPC etc. Windows isn't POSIX system so it has different API for it.
• undefined behavior for example, fflush(stdin) doesn't work on Unix
• data type size (the short=16 bit, int=long=32 bit)
• carriage return format: in the normal strings it's \n everywhere, but when written on file it's \n on *NIX, \r\n on Windows
• in particular, pointer size (void * isn't always 32 bit, and can't be always casted safely to an int); in general you should be careful with conversions and comparisons that involve pointers, and you should always use the provided types for that kind of tasks instead of "normal" ints (see in particular size_t and ptrdiff_t)
• data type "inner format" (the standard do not say that floats and doubles are in IEEE 754, although I've never seen platforms doing it differently);
• functions (__beginthread, MS safe strings functions; on the other side, POSIX/GNU extensions)
• compiler extensions (_inline, _declspec, #pragmas, ...) and in general anything that begins with double underscore (or even with a single underscore, in old, nonstandard implementations);
• console escape codes (this usually is a problem when you try to run Unix code on Windows);

What should You do?

If you're looking for the simplest route to convert from linux/unix to windows, try Cygwin and install the whole boat. It'll make a lot of the headaches go away when you port your code to windows.

The following resources may help you

• http://stackoverflow.com/questions/7830496/conversion-of-c-code-from-linux-to-windows
• http://stackoverflow.com/questions/6911250/how-do-i-convert-linux-c-source-code-into-windows-c-source-code
• http://social.msdn.microsoft.com/Forums/en/vcgeneral/thread/24194445-43d1-46b8-9db0-1356b10799b4
• https://bbs.archlinux.org/viewtopic.php?id=24491

If you have a good basic regarding Windows & Unix, it will help you

• http://bge-kernel-panic.blogspot.com/2005/07/difference-between-windows-and-unix.html

Answer 2

C standard is the same between these two operating systems. The difference is in the system programming. Traditionnaly, Unix systems are mainly written in C programming langage (cf. Single Unix Specification). Anyway, you can also use API Windows in a C program.