Q. I use vi / vim as IDE (Integrated development environment) a software development system using Ubuntu Linux. How do I auto complete file name under vim / vi text editor while editing text file or java / c / python program? I can auto complete file nameunder bash shell by hitting [TAB] key.

A. Yes, it is quite frustrating when you are not able to open files immediately. There is no need to add any special command for this task. All you have to do is press [Tab] key to complete directory or file names just like bash command. For example, while coding html file, if you would like to open email.php, just type following (ESC + : + em + hit [TAB] key):
:e em[TAB]
To auto complete directory name again hit [TAB]:
:cd /e[tab]
For further information see help page, by typing following command:
:help path
This works with vim version 6.1 and above. If you are using old version add following to your ~/.vimrc file:
map ,e :e <C-R>=expand("%:p:h") . "/" <CR>
Save and close the file. Then when you type ,e in normal mode you can use tab to complete to the file.