vim converting tabs to spaces

For converting tabs to spaces while editing the source codes

1) To insert space characters whenever the tab key is pressed.

 :set expandtab

2) To control the number of space characters that will be inserted when the tab key is pressed, set the 'tabstop' option.
To insert 4 spaces for a tab, you have to type the below command

:set tabstop=4

ctags useful tips

first run in the base directory ctags -R

In VI/VIM below commands can be used
Ctrl-] - go to function definition
Ctrl-T - Jump back from the definition.
Ctrl-W C-] - Open the definition in a horizontal split