How to detect the OS from a Bash script?

Question

I would like to keep my .bashrc and .bash_login files in version control so that I can use them between all the computers I use. The problem is I have some OS specific aliases so I was looking for a way to determine if the script is running on Mac OS X, Linux or Cygwin.

What is the proper way to detect the operating system in a Bash script?

Answer 1

$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" ;;
  *)        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

Answer 2

You can use following if clause and expand it as needed:

if [ "${OSTYPE//[0-9.]/}" == "darwin" ]
then
    aminute_ago="-v-1M"
elif  [ "${OSTYPE//[0-9.]/}" == "linux-gnu" ]
then
    aminute_ago="-d \"1 minute ago\""
fi

Answer 3

try this:

DISTRO=$(cat /etc/*-release | grep -w NAME | cut -d= -f2 | tr -d '"')
echo "Determined platform: $DISTRO"

Answer 4

I recommend to use this complete bash code

lowercase(){
    echo "$1" | sed "y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"
}

OS=`lowercase \`uname\``
KERNEL=`uname -r`
MACH=`uname -m`

if [ "{$OS}" == "windowsnt" ]; then
    OS=windows
elif [ "{$OS}" == "darwin" ]; then
    OS=mac
else
    OS=`uname`
    if [ "${OS}" = "SunOS" ] ; then
        OS=Solaris
        ARCH=`uname -p`
        OSSTR="${OS} ${REV}(${ARCH} `uname -v`)"
    elif [ "${OS}" = "AIX" ] ; then
        OSSTR="${OS} `oslevel` (`oslevel -r`)"
    elif [ "${OS}" = "Linux" ] ; then
        if [ -f /etc/redhat-release ] ; then
            DistroBasedOn='RedHat'
            DIST=`cat /etc/redhat-release |sed s/\ release.*//`
            PSUEDONAME=`cat /etc/redhat-release | sed s/.*\(// | sed s/\)//`
            REV=`cat /etc/redhat-release | sed s/.*release\ // | sed s/\ .*//`
        elif [ -f /etc/SuSE-release ] ; then
            DistroBasedOn='SuSe'
            PSUEDONAME=`cat /etc/SuSE-release | tr "\n" ' '| sed s/VERSION.*//`
            REV=`cat /etc/SuSE-release | tr "\n" ' ' | sed s/.*=\ //`
        elif [ -f /etc/mandrake-release ] ; then
            DistroBasedOn='Mandrake'
            PSUEDONAME=`cat /etc/mandrake-release | sed s/.*\(// | sed s/\)//`
            REV=`cat /etc/mandrake-release | sed s/.*release\ // | sed s/\ .*//`
        elif [ -f /etc/debian_version ] ; then
            DistroBasedOn='Debian'
            DIST=`cat /etc/lsb-release | grep '^DISTRIB_ID' | awk -F=  '{ print $2 }'`
            PSUEDONAME=`cat /etc/lsb-release | grep '^DISTRIB_CODENAME' | awk -F=  '{ print $2 }'`
            REV=`cat /etc/lsb-release | grep '^DISTRIB_RELEASE' | awk -F=  '{ print $2 }'`
        fi
        if [ -f /etc/UnitedLinux-release ] ; then
            DIST="${DIST}[`cat /etc/UnitedLinux-release | tr "\n" ' ' | sed s/VERSION.*//`]"
        fi
        OS=`lowercase $OS`
        DistroBasedOn=`lowercase $DistroBasedOn`
        readonly OS
        readonly DIST
        readonly DistroBasedOn
        readonly PSUEDONAME
        readonly REV
        readonly KERNEL
        readonly MACH
    fi

fi

more examples examples here: https://github.com/coto/server-easy-install/blob/master/lib/core.sh

Answer 5

In bash, use $OSTYPE and $HOSTTYPE, as documented; this is what I do. If that is not enough, and if even uname or uname -a (or other appropriate options) does not give enough information, there’s always the config.guess script from the GNU project, made exactly for this purpose.

Answer 6

I wrote these sugars in my .bashrc:

if_os () { [[ $OSTYPE == *$1* ]]; }
if_nix () { 
    case "$OSTYPE" in
        *linux*|*hurd*|*msys*|*cygwin*|*sua*|*interix*) sys="gnu";;
        *bsd*|*darwin*) sys="bsd";;
        *sunos*|*solaris*|*indiana*|*illumos*|*smartos*) sys="sun";;
    esac
    [[ "${sys}" == "$1" ]];
}

So I can do stuff like:

if_nix gnu && alias ls='ls --color=auto' && export LS_COLORS="..."
if_nix bsd && export CLICOLORS=on && export LSCOLORS="..."
if_os linux && alias psg="ps -FA | grep" #alternative to pgrep
if_nix bsd && alias psg="ps -alwx | grep -i" #alternative to pgrep
if_os darwin && alias finder="open -R"