Backup files with rsync:
rsync -a --delete /[FROM] /[TO]
Remove file permissions for everyone else:
chmod go= [FILE OR DIRECTORY]
Allow everyone else to read, write, and run a file:
chmod go=rwx [FILE OR DIRECTORY]
Compare files:
diff --suppress-common-lines [FILE] [FILE]
Compare files side by side:
diff -y [FILE] [FILE]
