Git config

System level : --systemoption. Affects all uses and repositories on the system(administrative)
Global user level : --globaloption. Affects all repositories of acurrent user
Local level : --localoption Specific to the current repository
git init : Initializing a Repository in an Existing Directory
git satus : Checking Repository Status
git add file_name : add a new file to be staged ex) git add . : add all files to staged
git rm -cached file_name : unstaging a file

Ignoring a File

ignore all .a files : *.a
but do track lib.a, even though you're ignoring .a files above : !lib.a
only ignore the TODO flies in any directory named build : build/
ignore doc/notes.txt, but no doc/server/arch.txt : doc/*.txt
ignore all .pdf files in the doc/directory and any of its subirectories : doc/**/*.pdf