Linux ls Command

>> ls [OPTION]... [FILE]...

>> ls 

# Use ls command to show files and directories inside current directory you are.

>> ls /

# Use ls / command to list the contents of the root directory

>> ls ..

# Use ls .. command to list the contents of the parent directory

>> ls ../..

# Use ls ../.. command to list the contents of two levels above of parent directory

>> ls ~

# Use ls ~ command to list the contents in the users's home directory

>> ls -d */ 

# Use ls -d */ command to list only directories

>> ls *

# Use ls * command to list the contents of the directory with it's subdirectories

>> ls -R

# Use ls -R command to list all files and directories with their corresponding subdirectories down to the last file

>> ls -s

# Use ls -s command (Note: s is in lowercase) to list files or directories with their sizes in bytes

>> ls -l

# Use ls -l command to list the contents of the directory in a table format with columns including

- content permissions
- number of links to the content
- owner of the content
- group owner of the content
- size of the content in bytes
- last modified date / time of the content
- file or directory name

>> ls -lh

# Use ls -lh command to list files or directories in a table format with their sizes

Note: The sizes are listed in bytes (B), megabytes (MB), gigabytes (GB), or terabytes (TB) when the file or directory's size is larger than 1024 bytes.

>> ls -a

# Use ls -a command to list files or directories including hidden files or directories. 
# Note: In Linux, anything that begins with a . is considered a hidden file

>> ls -a

# Use ls -l -a or ls -a -l or ls -la or ls -al command to list files or directories in a table format with extra information including hidden files or directories

>> ls -t

# Use ls -t command to list files or directories and sort by last modified date in descending order (biggest to smallest)

>> ls -S

# Use ls -S (the S is uppercase) command to list files or directories and sort by size in descending order (biggest to smallest).

>> ls -al > output.txt

# Use ls > output.txt command to print the output of the preceding command into an output.txt file.
Note: You can also use any of the flags discussed before like -lh

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
              with -l, scale sizes by SIZE when printing them; e.g., '--block-size=M'; 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 'always' (default if omitted), 'auto', or 'never'; 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;

              can be augmented with a --sort option, but any use of --sort=none (-U) disables grouping

       -G, --no-group
              in a long listing, don't print group names

       -h, --human-readable
              with -l and -s, print sizes like 1K 234M 2G etc.

       --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)
     --hyperlink[=WHEN]
              hyperlink file names; WHEN can be 'always' (default if omitted), 'auto', or 'never'

       --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; used only with -s and per directory totals

       -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 entry names without quoting

       -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, shell-escape, shell-es‐
              cape-always, c, escape (overrides QUOTING_STYLE environment variable)

       -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, largest first

       --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 (newest first)

       --time-style=TIME_STYLE
              time/date format with -l; see TIME_STYLE below

       -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, newest first

       -U     do not sort; list entries in directory order

       -v     natural sort of (version) numbers within text

       -w, --width=COLS
              set output width to COLS.  0 means no limit

       -x     list entries by lines instead of by columns

       -X     sort alphabetically by entry extension

       -Z, --context
              print any security context of each file

       -1     list one file per line.  Avoid '\n' with -q or -b

       --help display this help and exit

       --version
              output version information and exit

       The SIZE argument is an integer and optional unit (example: 10K is 10*1024).  Units are K,M,G,T,P,E,Z,Y  (pow‐
       ers of 1024) or KB,MB,... (powers of 1000).

       The  TIME_STYLE  argument  can  be full-iso, long-iso, iso, locale, or +FORMAT.  FORMAT is interpreted like in
       date(1).  If FORMAT is FORMAT1<newline>FORMAT2, then FORMAT1 applies to non-recent files and FORMAT2 to recent
       files.  TIME_STYLE prefixed with 'posix-' takes effect only outside the POSIX locale.  Also the TIME_STYLE en‐
       vironment variable sets the default style to use.

       Using color to distinguish file types is disabled both by default and with --color=never.  With  --color=auto,
       ls emits color codes only when standard output is connected to a terminal.  The LS_COLORS environment variable
       can change the settings.  Use the dircolors command to set it.