5.1.3 Sorting the output

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).

`-c'

`--time=ctime'

`--time=status'

`--time=use'

If the long listing format (e.g., `-l', `-o') is being used, print the status change time (the `ctime' in the inode) instead of the modification time. When explicitly sorting by time (`--sort=time' or `-t') or when not using a long listing format, sort according to the status change time.

`-f'

Primarily, like `-U'---do not sort; list the files in whatever order they are stored in the directory. But also enable `-a' (list all files) and disable `-l', `--color', and `-s' (if they were specified before the `-f').

`-r'

`--reverse'

Reverse whatever the sorting method is--e.g., list files in reverse alphabetical order, youngest first, smallest first, or whatever.

`-S'

`--sort=size'

Sort by file size, largest first.

`-t'

`--sort=time'

Sort by modification time (the `mtime' in the inode), newest first.

`-u'

`--time=atime'

`--time=access'

If the long listing format (e.g., `--format=long') is being used, print the last access time (the `atime' in the inode). When explicitly sorting by time (`--sort=time' or `-t') or when not using a long listing format, sort according to the access time.

`-U'

`--sort=none'

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 is especially useful when listing very large directories, since not doing any sorting can be noticeably faster.

`-v'

`--sort=version'

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 section 5.1.4 More details about version sort.)

`-X'

`--sort=extension'

Sort directory contents alphabetically by file extension (characters after the last `.'); files with no extension are sorted first.