These options change the order in which
ls sorts the information
it outputs. By default, sorting is done by character code
(e.g., ASCII order).
In long format, print the status change timestamp (the ctime) instead of the mtime. When sorting by time or when not using long format, sort according to the ctime. See File timestamps.
Produce an unsorted directory listing. This is equivalent to the combination of --all (-a), --sort=none (-U), -1, --color=none, and --hyperlink=none, while also disabling any previous use of --size (-s).
Reverse whatever the sorting method is—e.g., list files in reverse alphabetical order, youngest first, smallest first, or whatever. This option has no effect when --sort=none (-U) is in effect.
Sort by file size, largest first.
Sort by modification timestamp (mtime) by default, newest first. The timestamp to order by can be changed with the --time option. See File timestamps.
In long format, print the last access timestamp (the atime). When sorting by time or when not using long format, sort according to the atime. See File timestamps.
In long format, print the file creation timestamp if available. When sorting by time or when not using long format, sort according to the birth time. See File timestamps.
Do not sort; list the files in whatever order they are stored in the directory. (Do not do any of the other unrelated things that -f does.) This can be useful when listing large directories, where sorting can take some time.
Sort by version name and number, lowest first. It behaves like a default sort, except that each sequence of decimal digits is treated numerically as an index/version number. See Version sort ordering.
Sort by printed width of file names. This can be useful with the --format=vertical (-C) output format, to most densely display the listed files.
Sort directory contents alphabetically by file extension (characters after the last ‘.’); files with no extension are sorted first.