How to detect the OS from a Bash script?

Solution 1:

I think the following should work. I'm not sure about win32 though.

if [[ "$OSTYPE" == "linux-gnu"* ]]; then
        # ...
elif [[ "$OSTYPE" == "darwin"* ]]; then
        # Mac OSX
elif [[ "$OSTYPE" == "cygwin" ]]; then
        # POSIX compatibility layer and Linux environment emulation for Windows
elif [[ "$OSTYPE" == "msys" ]]; then
        # Lightweight shell and GNU utilities compiled for Windows (part of MinGW)
elif [[ "$OSTYPE" == "win32" ]]; then
        # I'm not sure this can happen.
elif [[ "$OSTYPE" == "freebsd"* ]]; then
        # ...
else
        # Unknown.
fi

Solution 2:

For my .bashrc, I use the following code:

platform='unknown'
unamestr=`uname`
if [[ "$unamestr" == 'Linux' ]]; then
   platform='linux'
elif [[ "$unamestr" == 'FreeBSD' ]]; then
   platform='freebsd'
fi

Then I do somethings like:

if [[ $platform == 'linux' ]]; then
   alias ls='ls --color=auto'
elif [[ $platform == 'freebsd' ]]; then
   alias ls='ls -G'
fi

It's ugly, but it works. You may use case instead of if if you prefer.

Solution 3:

The bash manpage says that the variable OSTYPE stores the name of the operation system:

OSTYPE Automatically set to a string that describes the operating system on which bash is executing. The default is system- dependent.

It is set to linux-gnu here.

Solution 4:

`$OSTYPE`

You can simply use pre-defined $OSTYPE variable e.g.:

case "$OSTYPE" in
  solaris*) echo "SOLARIS" ;;
  darwin*)  echo "OSX" ;; 
  linux*)   echo "LINUX" ;;
  bsd*)     echo "BSD" ;;
  msys*)    echo "WINDOWS" ;;
  cygwin*)  echo "ALSO WINDOWS" ;;
  *)        echo "unknown: $OSTYPE" ;;
esac

However it's not recognized by the older shells (such as Bourne shell).

`uname`

Another method is to detect platform based on uname command.

See the following script (ready to include in .bashrc):

# Detect the platform (similar to $OSTYPE)
OS="`uname`"
case $OS in
  'Linux')
    OS='Linux'
    alias ls='ls --color=auto'
    ;;
  'FreeBSD')
    OS='FreeBSD'
    alias ls='ls -G'
    ;;
  'WindowsNT')
    OS='Windows'
    ;;
  'Darwin') 
    OS='Mac'
    ;;
  'SunOS')
    OS='Solaris'
    ;;
  'AIX') ;;
  *) ;;
esac

You can find some practical example in my .bashrc.

Here is similar version used on Travis CI:

case $(uname | tr '[:upper:]' '[:lower:]') in
  linux*)
    export TRAVIS_OS_NAME=linux
    ;;
  darwin*)
    export TRAVIS_OS_NAME=osx
    ;;
  msys*)
    export TRAVIS_OS_NAME=windows
    ;;
  *)
    export TRAVIS_OS_NAME=notset
    ;;
esac

Solution 5:

Detecting operating system and CPU type is not so easy to do portably. I have a sh script of about 100 lines that works across a very wide variety of Unix platforms: any system I have used since 1988.

The key elements are

uname -p is processor type but is usually unknown on modern Unix platforms.
uname -m will give the "machine hardware name" on some Unix systems.
/bin/arch, if it exists, will usually give the type of processor.
uname with no arguments will name the operating system.

Eventually you will have to think about the distinctions between platforms and how fine you want to make them. For example, just to keep things simple, I treat i386 through i686 , any "Pentium*" and any "AMD*Athlon*" all as x86.

My ~/.profile runs an a script at startup which sets one variable to a string indicating the combination of CPU and operating system. I have platform-specific bin, man, lib, and include directories that get set up based on that. Then I set a boatload of environment variables. So for example, a shell script to reformat mail can call, e.g., $LIB/mailfmt which is a platform-specific executable binary.

If you want to cut corners, uname -m and plain uname will tell you what you want to know on many platforms. Add other stuff when you need it. (And use case, not nested if!)