[SOLVED] Detecting operating system (windos/linux) in Makefile

mastemmer · 04-20-2016, 04:14 PM

I am writing a Makefile (to use make) to compile a program that has to be multiplatform.
It will be used in a unix-shell or in a Windows(MSDOS) cmd.
The problem is that some commands are different in windos than in unix. I want to detect the OS and issue the right commands automatically.
If the Makefile has a way to detect whether it is in windows or in unix, I could make up for this differences using ifeq clauses.
The question is how can I detect whether it is running Windos or Linux in the Makefile?

linosaurusroot · 04-20-2016, 06:58 PM

Can you tell the difference in the output of this command between the systems?

Code:

zcat   /proc/config.gz

dugan · 04-20-2016, 09:04 PM

If you're using CMake to generate the Makefile, then you can just use:

Code:

IF (APPLE)
ENDIF (APPLE)

IF (UNIX)
ENDIF (UNIX)

For just Make, Google got me these:

linosaurusroot: your answer looks to me like it was intended to be as unhelpful as possible.

NevemTeve · 04-20-2016, 11:35 PM

in GNU-make:

Code:

PLATFORM := $(shell uname)

ifeq  ($(PLATFORM),Linux)
...
else
...
endif

mastemmer · 04-21-2016, 02:12 AM

Quote:

Originally Posted by dugan

If you're using CMake to generate the Makefile, then you can just use:

Code:

IF (APPLE)
ENDIF (APPLE)

IF (UNIX)
ENDIF (UNIX)

For just Make, Google got me these:

linosaurusroot: your answer looks to me like it was intended to be as unhelpful as possible.

Thank you dougan

The first link provides many useful hints.
There I found this:

Code:

ifeq ($(shell echo "check_quotes"),"check_quotes")
WINDOWS := yes
else
WINDOWS := no
endif

Testing in Linux it worked. I'll back soon after reboot to try it in Windos...

mastemmer · 04-21-2016, 02:24 AM

Jolly good! It worked in Windows as well.
Since only Windows uses different commands, this may be used to write a multiplattform Makefile.

It uses the fact that the command echo exists in both OS, but behaves differently.
Posix systems remove quotes, but windos-cmd don't.

Dave Nadler · 01-21-2023, 06:15 PM

Many development environments under Windows provide a unix-style 'echo' - which defeats this test. Examples: busybox, Eclipse environments from NXP and STM, etc.
Better to check if PATH variable contains semicolon, which it will not under unix.
Just got burned by this...
Hope that helps!
Best Regards, Dave