You can check the major and minor numbers of the CMake version installed on your system using the following command in Bash:

CMAKE_VERSION=$(cmake --version | grep -o -P -e "\d+\.\d+.\d+")
CMAKE_VERSION_MAJOR=$(echo $CMAKE_VERSION | cut -d "." -f 1)
CMAKE_VERSION_MINOR=$(echo $CMAKE_VERSION | cut -d "." -f 2)

The grep options

• -o is used to print only the matched pattern and not the entire line
• -P is used to enable Perl-compatible regular expressions

Should I use "positive lookbehind assertion": '(?<=cmake version )\d+\.\d+'?