How to check if running in Cygwin, Mac or Linux?
I have a shell script that is used both on Windows/Cygwin and Mac and Linux. It needs slightly different variables for each versions.
How can a shell/bash script detect whether it is running in Cygwin, on a Mac or in Linux?
Usually, uname with its various options will tell you what environment you're running in:
pax> uname -a
CYGWIN_NT-5.1 IBM-L3F3936 1.5.25(0.156/4/2) 2008-06-12 19:34 i686 Cygwin
pax> uname -s
CYGWIN_NT-5.1
And, according to the very helpful schot (in the comments), uname -s gives Darwin for OSX and Linux for Linux, while my Cygwin gives CYGWIN_NT-5.1 . But you may have to experiment with all sorts of different versions.
So the bash code to do such a check would be along the lines of:
unameOut="$(uname -s)"
case "${unameOut}" in
Linux*) machine=Linux;;
Darwin*) machine=Mac;;
CYGWIN*) machine=Cygwin;;
MINGW*) machine=MinGw;;
*) machine="UNKNOWN:${unameOut}"
esac
echo ${machine}
Note that I'm assuming here that you're actually running within CygWin (the bash shell of it) so paths should already be correctly set up. As one commenter notes, you can run the bash program, passing the script, from cmd itself and this may result in the paths not being set up as needed.
If you are doing that, it's your responsibility to ensure the correct executables (ie, the CygWin ones) are being called, possibly by modifying the path beforehand or fully specifying the executable locations (eg, /c/cygwin/bin/uname ).
Here is the bash script I used to detect three different OS type (GNU/Linux, Mac OS X, Windows NT)
Pay attention
#!/usr/bin/env bash instead of #!/bin/sh to prevent the problem caused by /bin/sh linked to different default shell in different platforms, or there will be error like unexpected operator, that's what happened on my computer (Ubuntu 64 bits 12.04). expr program unless you install it, so I just use uname . Design
uname to get the system information ( -s parameter). expr and substr to deal with the string. if elif fi to do the matching job. uname -s specification. Implementation
#!/usr/bin/env bash
if [ "$(uname)" == "Darwin" ]; then
# Do something under Mac OS X platform
elif [ "$(expr substr $(uname -s) 1 5)" == "Linux" ]; then
# Do something under GNU/Linux platform
elif [ "$(expr substr $(uname -s) 1 10)" == "MINGW32_NT" ]; then
# Do something under 32 bits Windows NT platform
elif [ "$(expr substr $(uname -s) 1 10)" == "MINGW64_NT" ]; then
# Do something under 64 bits Windows NT platform
fi
Testing
What I learned
References
Use uname -s because uname -o is not supported on some Operating Systems as Mac OS, Solaris...
The below snippet does not require bash (ie does not require #!/bin/bash )
#!/bin/sh
case "$(uname -s)" in
Darwin)
echo 'Mac OS X'
;;
Linux)
echo 'Linux'
;;
CYGWIN*|MINGW32*|MSYS*)
echo 'MS Windows'
;;
# Add here more strings to compare
# See correspondence table at the bottom of this answer
*)
echo 'other OS'
;;
esac
The below Makefile is inspired from Git project ( config.mak.uname ).
ifdef MSVC # Avoid the MingW/Cygwin sections
uname_S := Windows
else # If uname not available => 'not'
uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
endif
# Avoid nesting "if .. else if .. else .. endif endif"
# because maintenance of matching if/else/endif is a pain
ifeq ($(uname_S),Windows)
CC := cl
endif
ifeq ($(uname_S),OSF1)
CFLAGS += -D_OSF_SOURCE
endif
ifeq ($(uname_S),Linux)
CFLAGS += -DNDEBUG
endif
ifeq ($(uname_S),GNU/kFreeBSD)
CFLAGS += -D_BSD_ALLOC
endif
ifeq ($(uname_S),UnixWare)
CFLAGS += -Wextra
endif
...
See also this nice and complete answer about uname -s and Makefile .
The correspondence table in the bottom of this answer is from Wikipedia article about uname . Please contribute to keep it up-to-date (edit the answer or post a comment). You may also update the Wikipedia article and post a comment to notice me about your contribution ;-)
See also more sophisticated OS detection as done by the installation scripts of Git LSF.
Operating System uname -s
Mac OS X Darwin
Cygwin 32-bit (Win-XP) CYGWIN_NT-5.1
Cygwin 32-bit (Win-7 32-bit) CYGWIN_NT-6.1
Cygwin 32-bit (Win-7 64-bit) CYGWIN_NT-6.1-WOW64
Cygwin 64-bit (Win-7 64-bit) CYGWIN_NT-6.1
MinGW (Windows 7 32-bit) MINGW32_NT-6.1
MinGW (Windows 10 64-bit) MINGW64_NT-10.0
Interix (Services for UNIX) Interix MSYS MSYS_NT-6.1
Android Linux
coreutils Linux
CentOS Linux
Fedora Linux
Gentoo Linux
Red Hat Linux Linux
Linux Mint Linux
openSUSE Linux
Ubuntu Linux
Unity Linux Linux
Manjaro Linux Linux
OpenWRT r40420 Linux
Debian (Linux) Linux
Debian (GNU Hurd) GNU
Debian (kFreeBSD) GNU/kFreeBSD
FreeBSD FreeBSD
NetBSD NetBSD
DragonFlyBSD DragonFly
Haiku Haiku
NonStop NONSTOP_KERNEL
QNX QNX
ReliantUNIX ReliantUNIX-Y
SINIX SINIX-Y
Tru64 OSF1
Ultrix ULTRIX
IRIX 32 bits IRIX
IRIX 64 bits IRIX64
MINIX Minix
Solaris SunOS
UWIN (64-bit Windows 7) UWIN-W7
SYS$UNIX:SH on OpenVMS IS/WB
z/OS USS OS/390
Cray sn5176
(SCO) OpenServer SCO_SV
(SCO) System V SCO_SV
(SCO) UnixWare UnixWare
IBM AIX AIX
IBM i with QSH OS400
HP-UX HP-UX