Using Sublime Text with cmake (build system)

I am using Sublime Text in Ubuntu and learning OpenCV. Until today, I was using Sublime Text to write and save the code, and using Terminal for compiling.

I am compiling with the following code:

cmake .
make
./a.out

But for fast processing, I am trying to make my build system and I want to make this all automatically by pressing Ctrl + B

I've tried the following code in a custom build system but it fails:

{
    "cmd": ["cmake ."],
    "cmd": ["make"],
    "cmd": ["./a.o"],
    "selector": "source.c++",
    "shell": true,

    "windows":
    {
        "cmd": ["cl", "/Fo${file_path}", "/O2", "$file"],
        "selector": "source.c++",
        "shell": true
    }
}

Any ideas? Thanks.