ls

List directory contents.

 - List files one per line:
   ls -1

 - List all files, including hidden files:
   ls -a

 - Long format list (permissions, ownership, size and modification date) of all files:
   ls -la

 - Long format list with size displayed using human readable units (KB, MB, GB):
   ls -lh

 - Long format list sorted by size (descending):
   ls -lS

 - Long format list of all files, sorted by modification date (oldest first):
   ls -ltr