view only dir in console (linux)

$ cd dir
$ ls -d */

it will only list directories present in the current dir and neither files nor contents of subdirs.
It is useful if a dir contains many files and you need to print the list of subdirs only.

using mailx from command line

*) Using mailx for sending mail:

echo "this is a mail body\n~c other@example.com" | mailx -s "my subject" user@example.com

This will send mail
To: user@example.com
Cc: other@example.com
Subject: my subject

this is a mail body
-------------------------------------------------
the '\n~c other@example.com' will add the recipient to Cc list, as '~' tilde option only recognized by mailx cmd if present at start of line