I installed Github for Mac, which works fine, but I can't run git commands from Terminal. Do I have another git that needs to be installed? Or do I have to enable some optio within Github for Mac?
Starting May 2013 ("Installing Git from GitHub for Mac"), you don't have to install another git distribution: everything is included.
you can now easily install Git for use on the command line, without needing to download any separate packages.
And whenever we update the version of Git included with GitHub for Mac, you'll get the changes automatically – no work required on your part!you may notice some changes to the Preferences window.
On the newly renamed "Advanced" tab, simply click "Install Command Line Tools".You'll be prompted for an administrator password so that Git can be installed into
/usr/local/bin, and then you should very shortly see that it succeeded:
Git can be installed in a number of ways on OSX:
1) If you have MacPorts installed, you can install it through that by opening up a terminal and doing:
sudo port install git
2) Download it from the official site & mount & install the .dmg: http://git-scm.com/download/mac
https://help.github.com/articles/set-up-git#platform-mac has instructions on setting up git for the command line. (essentially download http://git-scm.com/download/mac and setup the config)
Note for windows users you can use a workaround program called "Git Bash" to approximate a unix like command line from which you can execute git commands.
来源：https://stackoverflow.com/questions/11872760/using-git-from-the-command-line-after-installing-github-for-mac