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→INVESTIGATION 3: QUOTING SPECIAL CHARACTERS
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">echo "* hello *"</span><br><br>Is there a difference between this command and the previous command?<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">echo '* hello *'</span><br><br>Is there any difference between this command and the two previous commands?<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">echo $USER</span><br><br>'''NOTE''': '''USER''' is an environment variable that stores the current user's login name.<br>The '''$''' character immediately followed by the environment variable name causes it to expand to the value<br>that the variable contains. Therefore the '''echo ''' command displays the current login name of the user.<br><br>
# Issue the following Linux command (using single quotes): <span style="color:blue;font-weight:bold;font-family:courier;">echo '$USER'</span><br><br>What happened? Why is the output display like this?<br><br>
# Issue the following Linux command (using double quotes): <span style="color:blue;font-weight:bold;font-family:courier;">echo "$USER"</span><br><br>What happened? Why?<br><br>
