Home Linux Learning Linux ls Command

Learning Linux ls Command

ls command is used to list information of files in respected directory.

LS(1)                                                                                                        User Commands                                                                                                        LS(1)

NAME
       ls - list directory contents

SYNOPSIS
       ls [OPTION]... [FILE]...

DESCRIPTION
       List information about the FILEs (the current directory by default).  Sort entries alphabetically if none of -cftuvSUX nor --sort is specified.

       Mandatory arguments to long options are mandatory for short options too.

       -a, --all
              do not ignore entries starting with .

       -A, --almost-all
              do not list implied . and ..

       --author
              with -l, print the author of each file

       -b, --escape
              print C-style escapes for nongraphic characters

       --block-size=SIZE
              scale sizes by SIZE before printing them; e.g., '--block-size=M' prints sizes in units of 1,048,576 bytes; see SIZE format below

       -B, --ignore-backups
              do not list implied entries ending with ~

       -c     with -lt: sort by, and show, ctime (time of last modification of file status information); with -l: show ctime and sort by name; otherwise: sort by ctime, newest first

       -C     list entries by columns

       --color[=WHEN]
              colorize the output; WHEN can be 'never', 'auto', or 'always' (the default); more info below

       -d, --directory
              list directories themselves, not their contents

       -D, --dired
              generate output designed for Emacs' dired mode

       -f     do not sort, enable -aU, disable -ls --color

       -F, --classify
              append indicator (one of */=>@|) to entries

       --file-type
              likewise, except do not append '*'

       --format=WORD
              across -x, commas -m, horizontal -x, long -l, single-column -1, verbose -l, vertical -C

       --full-time
              like -l --time-style=full-iso

       -g     like -l, but do not list owner

       --group-directories-first
              group directories before files;
			  
	    -G, --no-group
              in a long listing, don't print group names

       -h, --human-readable
              with -l, print sizes in human readable format (e.g., 1K 234M 2G)

       --si   likewise, but use powers of 1000 not 1024

       -H, --dereference-command-line
              follow symbolic links listed on the command line

       --dereference-command-line-symlink-to-dir
              follow each command line symbolic link

              that points to a directory

       --hide=PATTERN
              do not list implied entries matching shell PATTERN (overridden by -a or -A)

       --indicator-style=WORD
              append indicator with style WORD to entry names: none (default), slash (-p), file-type (--file-type), classify (-F)

       -i, --inode
              print the index number of each file

       -I, --ignore=PATTERN
              do not list implied entries matching shell PATTERN

       -k, --kibibytes
              default to 1024-byte blocks for disk usage

       -l     use a long listing format

       -L, --dereference
              when showing file information for a symbolic link, show information for the file the link references rather than for the link itself

       -m     fill width with a comma separated list of entries

       -n, --numeric-uid-gid
              like -l, but list numeric user and group IDs

       -N, --literal
              print raw entry names (don't treat e.g. control characters specially)

       -o     like -l, but do not list group information

       -p, --indicator-style=slash
              append / indicator to directories

       -q, --hide-control-chars
              print ? instead of nongraphic characters

       --show-control-chars
              show nongraphic characters as-is (the default, unless program is 'ls' and output is a terminal)

       -Q, --quote-name
              enclose entry names in double quotes

       --quoting-style=WORD
              use quoting style WORD for entry names: literal, locale, shell, shell-always, c, escape

        -r, --reverse
              reverse order while sorting

       -R, --recursive
              list subdirectories recursively

       -s, --size
              print the allocated size of each file, in blocks

       -S     sort by file size

       --sort=WORD
              sort by WORD instead of name: none (-U), size (-S), time (-t), version (-v), extension (-X)

       --time=WORD
              with -l, show time as WORD instead of default modification time: atime or access or use (-u) ctime or status (-c); also use specified time as sort key if --sort=time

       --time-style=STYLE
              with  -l,  show times using style STYLE: full-iso, long-iso, iso, locale, or +FORMAT; FORMAT is interpreted like in 'date'; if FORMAT is FORMAT1<newline>FORMAT2, then FORMAT1 applies to non-recent files and FORMAT2 to
              recent files; if STYLE is prefixed with 'posix-', STYLE takes effect only outside the POSIX locale

       -t     sort by modification time, newest first

       -T, --tabsize=COLS
              assume tab stops at each COLS instead of 8

       -u     with -lt: sort by, and show, access time; with -l: show access time and sort by name; otherwise: sort by access time

       -U     do not sort; list entries in directory order

       -v     natural sort of (version) numbers within text

       -w, --width=COLS
              assume screen width instead of current value

       -x     list entries by lines instead of by columns

       -X     sort alphabetically by entry extension

       -1     list one file per line

       SELinux options:

       --lcontext
              Display security context.   Enable -l. Lines will probably be too wide for most displays.

       -Z, --context
              Display security context so it fits on most displays.  Displays only mode, user, group, security context and file name.

       --scontext
              Display only security context and file name.

       --help display this help and exit

       --version
              output version information and exit

Lets start this tutorial.

mkdir sial
cd sial
touch ravi
touch mukesh
touch -t "201912081126" nikhil
touch .blank

As we have created a folder named sial and inside that we created four files ravi, mukesh, nikhil and .blank. You can see that for nikhil file I have specified date and time to year 2019, month December, date 08 and time created 11:26.

Lets use ls command

ls sial
[11:04][root@mail.bullten.work ~]# ls sial
mukesh  nikhil  ravi

In the above command you can see we can see all the files created but not the .blank file. It is a hidden file but we can list it too using the command below

ls -a sial
[11:05][root@mail.bullten.work ~]# ls -a sial
.  ..  .blank  mukesh  nikhil  ravi

Above you can see all the files we created. Now lets try some other command

ls -la sial
[11:06][root@mail.bullten.work ~]# ls -la sial
total 4
drwxr-xr-x   2 root root   60 Apr 14 11:02 .
dr-xr-x---. 12 root root 4096 Apr 14 11:01 ..
-rw-r--r--   1 root root    0 Apr 14 11:02 .blank
-rw-r--r--   1 root root    0 Apr 14 11:01 mukesh
-rw-r--r--   1 root root    0 Dec  8 11:26 nikhil
-rw-r--r--   1 root root    0 Apr 14 11:01 ravi

Using the above command we can see many information of directory and files. Like number of files in directory is 4 shows as total 4. We can also see what is the permission of the files, who owns it as in my example it is owned by root. What is size of the file and when it was created.

ls -lah sial
[11:10][root@mail.bullten.work ~]# ls -lah sial
total 4.0K
drwxr-xr-x   2 root root   60 Apr 14 11:02 .
dr-xr-x---. 12 root root 4.0K Apr 14 11:09 ..
-rw-r--r--   1 root root    0 Apr 14 11:02 .blank
-rw-r--r--   1 root root    0 Apr 14 11:01 mukesh
-rw-r--r--   1 root root    0 Dec  8 11:26 nikhil
-rw-r--r--   1 root root    0 Apr 14 11:01 ravi

We added ‘h’ to the command that means show the file size in human readable format.

ls -laht sial
[11:11][root@mail.bullten.work ~]# ls -laht sial
total 4.0K
dr-xr-x---. 12 root root 4.0K Apr 14 11:09 ..
drwxr-xr-x 2 root root 60 Apr 14 11:02 .
-rw-r--r-- 1 root root 0 Apr 14 11:02 .blank
-rw-r--r-- 1 root root 0 Apr 14 11:01 mukesh
-rw-r--r-- 1 root root 0 Apr 14 11:01 ravi
-rw-r--r-- 1 root root 0 Dec 8 11:26 nikhil

This command ‘t’ helps to sort the output of command in newest first order. You can see April 14th files are in first order and then December 8th.

ls -lahtr sial
[11:14][root@mail.bullten.work ~]# ls -lahtr sial
total 4.0K
-rw-r--r--   1 root root    0 Dec  8 11:26 nikhil
-rw-r--r--   1 root root    0 Apr 14 11:01 ravi
-rw-r--r--   1 root root    0 Apr 14 11:01 mukesh
-rw-r--r--   1 root root    0 Apr 14 11:02 .blank
drwxr-xr-x   2 root root   60 Apr 14 11:02 .
dr-xr-x---. 12 root root 4.0K Apr 14 11:09 ..

‘r’ is used to sort the order in reverse order. That means older first and then newest.

This was the small tutorial on how to use ls command.

Must Read

Routing Domain Name in Haproxy

I hope you are following the below guide. Now suppose you want to route domain name to open specific backend that have...

Enable Logging in Haproxy

HAProxy can emit log message for processing by a syslog server. This is compatible with familiar syslog tools like Rsyslog, as well...

Getting real IP in Nginx when behind cloudflare Haproxy

Create a file named cloudflare_ips.ls and in that add all the cloudflare IP's vi /etc/haproxy/cloudflare_ips.ls 173.245.48.0/20 103.21.244.0/22 103.22.200.0/22 103.31.4.0/22 141.101.64.0/18 108.162.192.0/18 190.93.240.0/20 188.114.96.0/20 197.234.240.0/22 198.41.128.0/17 162.158.0.0/15 104.16.0.0/12 172.64.0.0/13 131.0.72.0/22 2400:cb00::/32 2606:4700::/32 2803:f800::/32 2405:b500::/32 2405:8100::/32 2a06:98c0::/29 2c0f:f248::/32

Getting Real IP in HaproxyNginx configuration

Well its a little configuration can get real to nginx when haproxy is set as reverse proxy. Follow this...

Haproxy as Single Point to Failure Node With Glusterfs and MariaDB Maxscale Cluster

HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It...