# Sorting the linux ls command output

The ls command sort options are:

Option	Sort
none	by name, alphabetical order (1 < 11 < 2)
-r	reverse order
-U	no order
-v	by name, naturel order (1 < 2 < 11)
-S	by size, largest first
-X	by extension, alphabetically
-t	by last modification date (mtime), newer first
-c	by last change date (ctime), newer first
-u	by last access date (atime), newer first

# Alphabetical order (défaut)

The ls command sort file by alphabetical order by default:

> ls -l
total 28
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt

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TIP

The alphabetical order may not seem natural, especially when the filename contains numbers. See Natural order section.

WARNING

The -l option is here solely to show the file informations on which files are ordered. This option isn't required to actually sort the output.

# No order (faster)

Sometimes, their is no need to have the ls output sorted. If you have a huge number of files in a directory and don't want them sorted, it's way faster to ask for an unsorted list with the -U option. ls will use the directory order (which depends on your filesystem).

> ls -lU
total 28
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt

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# Reverse order

All order can be reversed with the -r option:

> ls -lr
total 28
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt

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# Natural order (version)

When filenames contain numbers, like in this page, the alphabetical order seems wrong (but is not 😛). The ls command provides the -v (version) option to change the order from alphabetical to natural.

> ls -lv
total 28
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt

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# Size order

To order the output by file size, simply use the -S (Size) option (larger files come first)

> ls -lS
total 28
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc 20 May 19 14:13 file-213.md
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt

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# File extension order

ls also provides a way to order it's output depending on the file extension with the -X (eXtension) option.

> ls -lX
total 28
-rw-rw-r--. 1 poc poc 20 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt

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# Last modification time order (mtime)

Last sort options are about file dates. The -t option allows to order the ls output on the file modification time (mtime, which is the last time the file content has changed).

> ls -lt
total 28
-rw-rw-r--. 1 poc poc 25 May 19 13:57 file-213.md
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-213.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:56 file-111.txt
-rw-rw-r--. 1 poc poc 25 May 19 13:56 file-2.txt
-rw-rw-r--. 1 poc poc 20 May 19 13:55 file-1.txt
-rw-rw-r--. 1 poc poc  2 May 19 11:09 file-21.txt
-rw-rw-r--. 1 poc poc  5 May 19 11:09 file-11.txt

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Their is two other dates tracked by the filesystem that can be used by ls to order its output: the last access time (atime) and the last change time (ctime, which take into account modifications on file content and metadata, like file owner and file permission).

# Last access time order (atime)

> ls -ltu
> ls -u

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# Last change time order (ctime)

> ls -ltc
> ls -c

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TIP

When used with the -l option, the -u and -c options only sort the output is the -t option is added. Otherwise (-l option is set but not the -t option), they only change the time shown by the -l option but not the order used.

> ls -ltu # show the last access time and order on it
> ls -lu  # show the last access time but order alphabetically

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WARNING

Their is no way to sort on the file creation time with the ls command simply because filesystems are not required to store it (some does, however, like ext4).