There are many ways to list files and display information about them on Linux systems. This post reviews a number of commands that provide details on files and provides options for customizing your file listings to meet your needs.
Most of the commands list files within individual directories while others reach as deeply into a file system as you care to look.
The primary command for listing files is, of course, ls. This command, however, has an extensive number of options for finding and listing just the files you want to see. Plus, there’s always find for helping with very specific file searches.
Listing files by name
The easiest way to list files by name is simply to list them using the ls command. Listing files by name (alphanumeric order) is, after all, the default. You can choose the ls (no details) or ls -l (lots of details) to determine your view.
$ ls | head -6 8pgs.pdf Aesthetics_Thank_You.pdf alien.pdf Annual_Meeting_Agenda-20190602.pdf bigfile.bz2 bin $ ls -l | head -6 -rw-rw-r-- 1 shs shs 10886 Mar 22 2019 8pgs.pdf -rw-rw-r-- 1 shs shs 284003 May 11 2019 Aesthetics_Thank_You.pdf -rw-rw-r-- 1 shs shs 38282 Jan 24 2019 alien.pdf -rw-rw-r-- 1 shs shs 97358 May 19 2019 Annual_Meeting_20190602.pdf -rw-rw-r-- 1 shs shs 18115234 Apr 16 17:36 bigfile.bz2 drwxrwxr-x 4 shs shs 8052736 Jul 10 13:17 bin
Pipe the output of ls to the more command if you want to review your listing a screenful at a time.
Listing files in reverse name order
To reverse the listing of files by name, add the -r (reverse) option. This will be like turning the normal listing upside down.
$ ls -r $ ls -lr
Listing files by file extension
The ls command doesn’t analyze file types by content, but works with file names. There is, however, a command option that can list files by extension. If you add the -X option, ls will sort files by name within each extension category. For example, it will list files without extensions first (in alphanumeric order) followed by files with extensions like .1, .bz2, .c and so on.
Listing directories only
By default, the ls command will show both files and directories. If you want to list only directories, you can use the -d option. You will get a listing like this one:
$ ls -d */ 1/ backups/ modules/ projects/ templates/ 2/ html/ patches/ public/ videos/ bin/ new/ private/ save/
Listing files by size
If you want to list files in size order, add the -S option. Note, however, that this won’t actually show you the sizes (along with other file details) unless you also add the -l (long listing) option. When listing files by size, it’s generally helpful to see that the command is doing what you asked. Notice that the default is to show the largest files first. Add the -r option to reverse this (i.e., ls -lSr).
$ ls -lS total 959492 -rw-rw-r-- 1 shs shs 357679381 Sep 19 2019 sav-linux-free-9.tgz -rw-rw-r-- 1 shs shs 103270400 Apr 16 17:38 bigfile -rw-rw-r-- 1 shs shs 79117862 Oct 5 2019 Nessus-8.7.1-ubuntu1110_amd64.deb
Listing files by owner
If you want to list files by owner (e.g., in a shared directory), you can pass the output of the ls command to sort and pick out the owner column by adding -k3 to sort on the third field.
$ ls -l | sort -k3 | more total 56 -rw-rw-r-- 1 dory shs 0 Aug 23 12:27 tasklist drwx------ 2 gdm gdm 4096 Aug 21 17:12 tracker-extract-files.121 srwxr-xr-x 1 root root 0 Aug 21 17:12 ntf_listenerc0c6b8b4567 drwxr-xr-x 2 root root 4096 Aug 21 17:12 hsperfdata_root
^
|
In fact, you can sort on any field this way (e.g., year). Just be careful to add an “n” – -k5n – if you’re sorting on a field which is numeric or you’ll be sorting in alphanumeric order. This sorting technique is useful for sorting file contents as well, not just listing files.
Listing files by age
Use the -t option to list files in order of age – how new they are. Add the -r option to get the most recently updated files showing up last in the list. I use this alias to show me a list of the files that I’ve most recently updated:
$ alias recent='ls -ltr | tail -8'
Note that file change and modification times are different. The -c (change) and -t (modification) options will not always give the same results. If you change permissions on a file and nothing else, -c will put that files at the top of the ls output while -t will not. If you’re curious about the difference, look at the output of the stat command.
$ stat ckacct File: ckacct Size: 200 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 829041 Links: 1 Access: (0750/-rwxr-x---) Uid: ( 1000/ shs) Gid: ( 1000/ shs) Access: 2020-08-20 16:10:11.063015008 -0400 Modify: 2020-08-17 07:26:34.579922297 -0400 <== content changes Change: 2020-08-24 09:36:51.699775940 -0400 <== content or permissions changes Birth: -
Listing files by group
To sort files by the associated groups, you can pass the output from a long listing to the sort command and tell it to sort on column 4.
$ ls -l | sort -k4
Listing files by access date
To list files by access date (most recently accessed first), use the -ltu options. The “u” enforces the “by access date” listing order.
$ ls -ltu total 959500 -rwxr-x--- 1 shs shs 200 Aug 24 09:42 ckacct <== most recently used -rw-rw-r-- 1 shs shs 1335 Aug 23 17:45 lte
Listing multiple files on a single line
Sometimes a condensed file listing is more appropriate for the task at hand. The ls command even has options for that. To list files on as few lines as possible, you can use –format=comma to separate file names with commas as in this command:
$ ls --format=comma 1, 10, 11, 12, 124, 13, 14, 15, 16pgs-landscape.pdf, 16pgs.pdf, 17, 18, 19, 192.168.0.4, 2, 20, 2018-12-23_OoS_2.pdf, 2018-12-23_OoS.pdf, 20190512_OoS.pdf, '2019_HOHO_application working.pdf' …
Prefer white space? Use –format=across instead.
$ ls --format=across z* z zip zipfiles zipfiles1.bat zipfiles2.bat zipfiles3.bat zipfiles4.bat zipfiles.bat zoom_amd64.deb zoomap.pdf zoom-mtg
Adding depth to your searches
While ls generally lists files in a single directory, you can choose instead to recursively list files by using the -R options, delving into the entire depth of directories:
$ ls -R zzzzz | grep -v "^$" zzzzz: zzzz zzzzz/zzzz: zzz zzzzz/zzzz/zzz: zz zzzzz/zzzz/zzz/zz: z zzzzz/zzzz/zzz/zz/z: sleeping
Alternately, you can use a find command with a limited or unlimited depth specification. In this command, we instruct the find command to look in only three levels of directories:
$ find zzzzz -maxdepth 3 zzzzz zzzzz/zzzz zzzzz/zzzz/zzz zzzzz/zzzz/zzz/zz
Choosing ls vs find
When you need to list files that meet a very selective list of requirements, the find command is probably a better tool to use than ls.
Unlike ls, the find command looks as deeply as possible unless you constrain it. It also has many other options and an -exec command that allows you to take some specific action once you find the files you’re looking for.
Wrap-Up
The ls command has a lot of options for listing files. Check them out. You might find some that you’ll love.
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