==== sort ls output by filename length ====
<code>
ls --color=never --indicator-style=none | awk '{print length, $0}' |
sort -n | cut -d" " -f2-
</code>

To see it in action, create some files
<code>
% touch a ab abc
</code>

and some directories
<code>
% mkdir d de def
</code>

Output of the normal ls command
<code>
% ls
a  ab  abc  d/  de/  def/
</code>

Output from the proposed command
<code>
% ls --color=never --indicator-style=none | awk '{print length, $0}' |
sort -n | cut -d" " -f2-
a
d
ab
de
abc
def
</code>

Ref:- https://stackoverflow.com/a/70628169
==== Show file date in different date formats ====
tags | YYYY-MM-DD, YYYYMMDD, YYYYMMDD_HHMMSS

Use one of
<code>
--time-style='+%Y%m%d_%H%M%S'
--time-style='+%Y-%m-%d'
--time-style='+%Y%m%d'
</code>

For example
<code>
% ls -l --time-style='+%Y%m%d_%H%M%S' ~/.vimrc
-rwx------ 1 rajulocal rajulocal 1112 20201017_141554 /home/rajulocal/.vimrc*

% ls -l --time-style='+%Y-%m-%d' ~/.vimrc
-rwx------ 1 rajulocal rajulocal 1112 2020-10-17 /home/rajulocal/.vimrc*

% ls -l --time-style='+%Y%m%d' ~/.vimrc 
-rwx------ 1 rajulocal rajulocal 1112 20201017 /home/rajulocal/.vimrc*
</code>

==== indicators ====
"ls -F" appends indicators <nowiki>*/=>@|</nowiki> to filenames.
  * * means executable.
  * / means directory.
  * = means socket.
  * > means door.
  * @ means symbolic link (or that the file has extended attributes).
  * | means named pipe.

Ref:- https://unix.stackexchange.com/questions/82357/what-do-the-symbols-displayed-by-ls-f-mean

==== only show filename and modification time ====
<code>
ls -al | cut -d ' ' -f 6- 
</code>

Another way (using find):
<code>
find -maxdepth 1 -type f -printf "%TY %Tb %Td %TH:%TM\t%p\n"
</code>

To sort the files based on timestamp (reverse chronological order)
<code>
find -maxdepth 1 -type f -printf "%T+#%TY %Tb %Td %TH:%TM\t%p\n" | sort -rn| cut -d# -f2-
</code>

The %T+ is used to sort the output properly and gets removed by cut afterwards.

Ref:- https://askubuntu.com/a/1044206/574082