VIM

* Changing the tab width to 4 spaces permanenlty
    Add the following to .vimrc (create one if not found in ~/)
        filetype plugin indent on
        " show existing tab with 4 spaces width
        set tabstop=4
        " when indenting with '>', use 4 spaces width
        set shiftwidth=4
        " On pressing tab, insert 4 spaces
        set expandtab
    Ref: http://stackoverflow.com/questions/234564/tab-key-4-spaces-and-auto-indent-after-curly-braces-in-vim 

Indenting a block of codes in Vim
    V j j >
    Ref: http://stackoverflow.com/questions/235839/indent-multiple-lines-quickly-in-vi