command cheat sheet

How to mkdir only if a dir does not already exist

reference url:
http://stackoverflow.com/questions/793858/how-to-mkdir-only-if-a-dir-does-not-already-exist

Try mkdir -p:

mkdir -p foo

Note that this will also create any intermediate directories that don't exist; for instance,

mkdir -p foo/bar/baz

will create directories foo, foo/bar, and foo/bar/baz if they don't exist.

比較不同電腦資料夾差異

rsync compare

rsync -rvnc --delete website/ laptop:projects/website/

man rsync|grep -e ' -n'

-n, --dry-run               perform a trial run with no changes made 

http://psung.blogspot.tw/2008/06/comparing-directory-trees-with-diff-or.html