View disk space:

df -ah

View directory listing for /etc/init.d:

ls -la /etc/init.d

Get more info for a file:

stat -x <FILE NAME>

Identify file type:

file <FILE NAME>

Look for immutable files:

lsattr -R / | grep \\-i-"

View directory listing for /root:

ls -la /root

Look for files recently modified in current directory:

ls -alt | head

Look for world writable files:

find / -xdev -type d\\( -perm -0002 -a ! -perm -1000 \\) -print

Look for recent created files, in this case newer than Jan 02, 2017:

find/ -n newermt 2017-01-02q

List all files and attributes:

find/ -printf
%m;%Ax;%AT;%Tx;%TT;%Cx;%CT;%U;%G;%s;%p\\n"