Command LS, which list files in Mac operating systems, sort by lexicographic order.
-R : search through folders recursively
-l : display long format, with detailed information about the file
-t : sort by modification time
-a : include hidden files
-r : reverse sorting
-G : colors, 11 colors for types, permissions or user
-S : sort by size
-u : display or sort by last access time with -l and -t, no effect otherwise
-U : display or sort by birth time with -l and -t, no effect otherwise
-f : no acsii sorting + option 'a' active
-1 : display in a single column (default is in column)
All sorts are executed with a merge sort algorithm on linked lists.