echo “Hello World”
is equal to /usr/bin/echo “Hello World”
"man is the system's manual pager. Each page argument given to man is normally the name of a program, utility or function. The manual page associated with each of these arguments is then found and displayed. A section, if provided, will direct man to look only in that section of the manual. The default action is to search in all of the avail‐ able sections following a pre-defined order (see DEFAULTS), and to show only the first page found, even if page exists in several sections."
~
symbol.
In this case ~
refers to /home/adam
. The root user, has /root as the default directory.-lh
refers to list, human readable. Type man ls
to see more arguments.file.txt
is read as a shell script in Linux, and would be read as a text file on Windows.~
to ~/test
. /root
, require superuser permissions to go there.
You can type sudo cd /root
to execute a command as the superuser.rm -rf
can be a dangerous command. Once a file is deleted, it cannot be recovered easily.-r
(recursive) flag needs to be used.