How to use gcc or git without installing xcode?

I am a newbie of Mac user. I can see there are gcc, git, etc in the "/usr/bin" folder. But when I want to use them, it prompts like this:

MacBook-Pro:~ nan$ git
xcode-select: note: no developer tools were found at '/Applications/Xcode.app', requesting install. Choose an option in the dialog to download the command   line developer tools.
MacBook-Pro:~ nan$ gcc
xcode-select: note: no developer tools were found at '/Applications/Xcode.app', requesting install. Choose an option in the dialog to download the command line developer tools.

Does it mean I must install xcode to use gcc or git, thanks very much in advance!