git current branch

#
# 1) add function to add to your ~/.profile or ~/.bashrc (or aliases) file
#

_current_branch () {
        ref=$(git symbolic-ref HEAD 2>/dev/null)  || head=$(git rev-parse --short HEAD 2>/dev/null)
        echo ${ref#refs/heads/}
}

#
# 2) add function call to your prompt
#
# /!\ take care to escape $ to evaluate expression each time it's displayed
#
export PS1="$PS1 \$(_current_branch) >"