13,420
edits
Changes
→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 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 $USER</span><br><br>'''NOTE''': The environment variable '''USER''' contains the current user's login name.<br>The '''$''' character immediately followed by the environment variable name causes it to<br>expand to the '''value''' that the variable contains.<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>
# Let's use quoting special characters for a couple of other commands. Move to the '''lesson2''' directory. Confirm that you are currently located in the ''lesson2'' directory.<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">cp /bin/ls .</span><br><br>