how to create or edit or modif a configuration file with vim

http://www.youtube.com/watch?v=ImK_dHPOTIE

• vim is use to modify configuration file (ex.: ini)
• sudo vim filename (...to create filename or open filename)
• sudo chown username filename (...to change the filename ownership to username denis in order for me-denis to be able to modify and save the file) 
• sudo chown newfile root (the owner of newfile is now root)
• sudo chown newfile denis (the owner of newfile is now denis)
• sudo vim /etc/passwd (to open user account file)
• :q (to quit an open file with vim)
• a (in vim, type a to activate insert mode, press esc to quit insert mode)
• escape the edit mode to find something in the file (ex.: *max*)
• :/ *max* (find downward in the file anything with max in it, *=wild card)
• :/? *max* (find upward in the file anything with max in it, *=wild card)
• press n to find the next *max* word 
• sudo vim (to open vim editor)
• :e filename (to open filename)
• :q (quit, no save)
• :q! (forced quit, no save)
• :wq (save-overwrite and quit)
• :wq newfilename (save as newfilename and quit)
• $clear (to clean terminal window)
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