CODEWITHSUNDEEP
clinuxtestingposixcompatibility
Squall
Squall

Reputation: 4472

How to test POSIX compatibility?

I am writing a C program with POSIX API and using Linux. I compiled and ran it on a friend's Mac OSX PC and there was a small error, but I did not use Linux specific features.

I will use some specific features that Linux adds to the API. I will also use specific POSIX extensions for Mac Os X and FreeBSD.
I will use conditional compilation to choose the code. If the OS is none of those, I will use generic POSIX code.

I do not own Darwin/Mac OSX and FreeBSD, Linux is the only OS that I have in my PC. I cannot download and install FreeBSD, because it is more than 500 MB.
I want to know a way to test if the program will compile and behave as expected on other POSIX systems.
I wonder if there is a POSIX simulator and compiler to do tests.
The tests are simple, they do not use GUI and drivers, they are only command line.

I will need to do 3 tests: FreeBSD, Mac OSX/Darwin and Generic POSIX, but I do not have the tools.

EDIT

Is there a minimal version of FreeBSD and Darwin without GUI, but with GCC/G++ and ssh/scp? Darwin is free, is not it?
My PC is old, but I think I can install them in a virtual machine, create a virtual network and use ssh/scp to transfer and test the programs.

Upvotes: 5

Views: 3549

Answers (2)

R.. GitHub STOP HELPING ICE
R.. GitHub STOP HELPING ICE

Reputation: 215427

One simple way is to compile your program with the proper feature test macros. For example if you define _POSIX_C_SOURCE to the target version of POSIX (currently 200809L), you will request the system headers expose to your program nothing except what's needed/allowed by POSIX base. This can be done via the command line CFLAGS with -D_POSIX_C_SOURCE=200809L. If you want the XSI option (full Single Unix Standard functionality, which is a superset of POSIX base) then use -D_XOPEN_SOURCE=700 instead.

This will not help you detect problems that come from either certain systems lacking POSIX functionality (for example, OSX is broken and lacks a working sem_init last I checked, even though it's mandatory in POSIX), or from writing code that depends on non-standard behavior in the POSIX-standard interfaces (for example, using GNU regex extensions in the expressions you pass to regcomp) but it will help you catch any accidental usage of interfaces not in the standard.

Upvotes: 6

MByD
MByD

Reputation: 137382

If you want to compile for other system, you usually don't need to have the other system, you just need an appropriate cross compiler.

Upvotes: 1

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