ls command is one of the most frequently used command in Linux. I believe ls command is the first command you may use when you get into the command prompt of Linux Box.
We use ls command daily basis and frequently even though we may not aware and never use all the ls option available. In this article, we’ll be discussing basic ls command where we have tried to cover as much parameters as possible.
Linux ls Command
1. List Files using ls with no option
ls with no option list files and directories in bare format where we won’t be able to view details like file types, size, modified date and time, permission and links etc.
# ls 0001.pcap Desktop Downloads index.html install.log.syslog Pictures Templates anaconda-ks.cfg Documents fbcmd_update.php install.log Music Public Videos
2 List Files With option –l
Here, ls -l (-l is character not one) shows file or directory, size, modified date and time, file or folder name and owner of file and its permission.
# ls -l total 176 -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap -rw-------. 1 root root 1586 Jul 31 02:17 anaconda-ks.cfg drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Documents drwxr-xr-x. 4 root root 4096 Aug 16 02:55 Downloads -rw-r--r--. 1 root root 21262 Aug 12 12:42 fbcmd_update.php -rw-r--r--. 1 root root 46701 Jul 31 09:58 index.html -rw-r--r--. 1 root root 48867 Jul 31 02:17 install.log -rw-r--r--. 1 root root 11439 Jul 31 02:13 install.log.syslog drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Music drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Public drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Videos
3. View Hidden Files
List all files including hidden file starting with ‘.‘.
# ls -a . .bashrc Documents .gconfd install.log .nautilus .pulse-cookie .. .cache Downloads .gnome2 install.log.syslog .netstat.swp .recently-used.xbel 0001.pcap .config .elinks .gnome2_private .kde .opera .spice-vdagent anaconda-ks.cfg .cshrc .esd_auth .gtk-bookmarks .libreoffice Pictures .tcshrc .bash_history .dbus .fbcmd .gvfs .local .pki Templates .bash_logout Desktop fbcmd_update.php .ICEauthority .mozilla Public Videos .bash_profile .digrc .gconf index.html Music .pulse .wireshark
4. List Files with Human Readable Format with option -lh
With combination of -lh option, shows sizes in human readable format.
# ls -lh total 176K -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap -rw-------. 1 root root 1.6K Jul 31 02:17 anaconda-ks.cfg drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Documents drwxr-xr-x. 4 root root 4.0K Aug 16 02:55 Downloads -rw-r--r--. 1 root root 21K Aug 12 12:42 fbcmd_update.php -rw-r--r--. 1 root root 46K Jul 31 09:58 index.html -rw-r--r--. 1 root root 48K Jul 31 02:17 install.log -rw-r--r--. 1 root root 12K Jul 31 02:13 install.log.syslog drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Music drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Public drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Videos
5. List Files and Directories with ‘/’ Character at the end
Using -F option with ls command, will add the ‘/’ Character at the end each directory.
# ls -F 0001.pcap Desktop/ Downloads/ index.html install.log.syslog Pictures/ Templates/ anaconda-ks.cfg Documents/ fbcmd_update.php install.log Music/ Public/ Videos/
6. List Files in Reverse Order
The following command with ls -r option display files and directories in reverse order.
# ls -r Videos Public Music install.log fbcmd_update.php Documents anaconda-ks.cfg Templates Pictures install.log.syslog index.html Downloads Desktop 0001.pcap
7. Recursively list Sub-Directories
ls -R option will list very long listing directory trees. See an example of output of the command.
# ls -R total 1384 -rw-------. 1 root root 33408 Aug 8 17:25 anaconda.log -rw-------. 1 root root 30508 Aug 8 17:25 anaconda.program.log ./httpd: total 132 -rw-r--r-- 1 root root 0 Aug 19 03:14 access_log -rw-r--r--. 1 root root 61916 Aug 10 17:55 access_log-20120812 ./lighttpd: total 68 -rw-r--r-- 1 lighttpd lighttpd 7858 Aug 21 15:26 access.log -rw-r--r--. 1 lighttpd lighttpd 37531 Aug 17 18:21 access.log-20120819 ./nginx: total 12 -rw-r--r--. 1 root root 0 Aug 12 03:17 access.log -rw-r--r--. 1 root root 390 Aug 12 03:17 access.log-20120812.gz
8. Reverse Output Order
With combination of -ltr will shows latest modification file or directory date as last.
# ls -ltr total 176 -rw-r--r--. 1 root root 11439 Jul 31 02:13 install.log.syslog -rw-r--r--. 1 root root 48867 Jul 31 02:17 install.log -rw-------. 1 root root 1586 Jul 31 02:17 anaconda-ks.cfg drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Videos drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Public drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Music drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Documents -rw-r--r--. 1 root root 46701 Jul 31 09:58 index.html -rw-r--r--. 1 root root 21262 Aug 12 12:42 fbcmd_update.php drwxr-xr-x. 4 root root 4096 Aug 16 02:55 Downloads -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap
9. Sort Files by File Size
With combination of -lS displays file size in order, will display big in size first.
# ls -lS total 176 -rw-r--r--. 1 root root 48867 Jul 31 02:17 install.log -rw-r--r--. 1 root root 46701 Jul 31 09:58 index.html -rw-r--r--. 1 root root 21262 Aug 12 12:42 fbcmd_update.php -rw-r--r--. 1 root root 11439 Jul 31 02:13 install.log.syslog drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Documents drwxr-xr-x. 4 root root 4096 Aug 16 02:55 Downloads drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Music drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Public drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Videos -rw-------. 1 root root 1586 Jul 31 02:17 anaconda-ks.cfg -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap
10. Display Inode number of File or Directory
We can see some number printed before file / directory name. With -i options list file / directory with inode number.
# ls -i 20112 0001.pcap 23610 Documents 23793 index.html 23611 Music 23597 Templates 23564 anaconda-ks.cfg 23595 Downloads 22 install.log 23612 Pictures 23613 Videos 23594 Desktop 23585 fbcmd_update.php 35 install.log.syslog 23601 Public
11. Shows version of ls command
Check version of ls command.
# ls --version ls (GNU coreutils) 8.4 Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by Richard M. Stallman and David MacKenzie.
12. Show Help Page
List help page of ls command with their option.
# ls --help Usage: ls [OPTION]... [FILE]...
13. List Directory Information
With ls -l command list files under directory /tmp. Wherein with -ld parameters displays information of /tmp directory.
# ls -l /tmp total 408 drwx------. 2 narad narad 4096 Aug 2 02:00 CRX_75DAF8CB7768 -r--------. 1 root root 384683 Aug 4 12:28 htop-1.0.1.tar.gz drwx------. 2 root root 4096 Aug 4 11:20 keyring-6Mfjnk drwx------. 2 root root 4096 Aug 16 01:33 keyring-pioZJr drwx------. 2 gdm gdm 4096 Aug 21 11:26 orbit-gdm drwx------. 2 root root 4096 Aug 19 08:41 pulse-gl6o4ZdxQVrX drwx------. 2 narad narad 4096 Aug 4 08:16 pulse-UDH76ExwUVoU drwx------. 2 gdm gdm 4096 Aug 21 11:26 pulse-wJtcweUCtvhn -rw-------. 1 root root 300 Aug 16 03:34 yum_save_tx-2012-08-16-03-34LJTAa1.yumtx
# ls -ld /tmp/ drwxrwxrwt. 13 root root 4096 Aug 21 12:48 /tmp/
14. Display UID and GID of Files
To display UID and GID of files and directories. use option -n with ls command.
# ls -n total 36 drwxr-xr-x. 2 500 500 4096 Aug 2 01:52 Downloads drwxr-xr-x. 2 500 500 4096 Aug 2 01:52 Music drwxr-xr-x. 2 500 500 4096 Aug 2 01:52 Pictures -rw-rw-r--. 1 500 500 12 Aug 21 13:06 tmp.txt drwxr-xr-x. 2 500 500 4096 Aug 2 01:52 Videos
15. ls command and its Aliases
We have made alias for ls command, when we execute ls command it’ll take -l option by default and display long listing as mentioned earlier.
# alias ls="ls -l"
Note: We can see number of alias available in your system with below alias command and same can be unalias as shown below example.
# alias alias cp='cp -i' alias l.='ls -d .* --color=auto' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
To remove an alias previously defined, just use the unalias command.
# unalias ls
In our next article we’ll cover up more or advanced ls command with their examples. Also I suggest you to go through some interview questions on ls command and also if we’ve missed anything in the list, please update us via comment section.
Source: tecmint.com
