# -v (verbose) option will give you details about the connection process of SSH. This is useful when troubleshooting a troublesome connection.
ssh -v user@linuxconfig.org
# To increase verbosity even further
ssh -vvv user@linuxconfig.org
# SSH Version on client machine
ssh -V
# OpenSSH_7.4p1 Debian-10+deb9u7, OpenSSL 1.0.2u 20 Dec 2019
$SHLVL Variable
The $SHLVL variable tells you how many shells deep you are.
echo $SHLVL
To see which shells are already installed for your distribution, run cat /etc/shells.
cat /etc/shells
uname
Check permissions with stat
stat -c "%a %A" [FILE_PATH]
# or just `stat` but that prints extraneous info that if you just want the permission number
# "%a" --- access rights in octal (note '#' and '0' print f flags)
# "%A" --- acess rights in human readable form