If you're using homebrew, it's simple:
$ brew install git-flow
If you're using MacPorts, it's simple, too:
$ port install git-flow
If you run into problems due to Xcode 4.2 upgrades & MacPorts 2.04 with the expat dependency not installing then simply use the workaround specified in https://trac.macports.org/wiki/ProblemHotlist like so:
$ sudo port install expat ---> Configuring expat Error: Target org.macports.configure returned: configure failure: shell command failed (see log for details) Log for expat is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_textproc_expat/expat/main.log Error: Status 1 encountered during processing. To report a bug, see <http://guide.macports.org/#project.tickets> $ sudo port clean expat ---> Cleaning expat $ sudo port install expat configure.compiler=llvm-gcc-4.2 ---> Fetching archive for expat ---> Attempting to fetch expat-2.1.0_0.darwin_11.x86_64.tbz2 from http://packages.macports.org/expat ---> Attempting to fetch expat-2.1.0_0.darwin_11.x86_64.tbz2.rmd160 from http://packages.macports.org/expat ---> Installing expat @2.1.0_0 ---> Activating expat @2.1.0_0 ---> Cleaning expat $ port install git-flow
Even using wget its a one line effort.
wget --no-check-certificate -q -O - https://github.com/nvie/gitflow/raw/develop/contrib/gitflow-installer.sh | sudo bash
wget: command not found? curl is only two lines.
curl -L -O https://raw.github.com/nvie/gitflow/develop/contrib/gitflow-installer.sh sudo bash gitflow-installer.sh