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→INVESTIGATION 2: REDIRECTION USING PIPELINE COMMANDS
# Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin | who</span><br><br>What happened? This won't work since the '''who''' command is<br>'''NOT''' designed to accept standard input.[[Image:pipe-diagram-1.png|thumb|right|350px|]]<br><br>'''NOTE:''' When issuing pipeline commands, commands to the right of the pipe symbol must be designed to <u>accept</u> '''standard input'''. Since the ''who'' command does not, you did NOT see the contents of the '''/bin''' directory but only information relating to the ''who'' command. Therefore, the '''order''' of which you build your pipeline command and the '''type of command''' that is used as a ''filter'' is extremely important!<br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/?? > listing.txt</span><br><br>
# Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">sort -r listing.txt</span><br><br>
# Issue the following Linux command to remove the listing file: <span style="color:blue;font-weight:bold;font-family:courier;">rm listing.txt</span><br><br>
# Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/?? | sort -r</span><br><br>You should notice that the output from this pipeline command is the same output<br>from the command you issued in '''step #7'''<br><br># Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/?? | sort -r | more</span><br><br>What is different with this pipeline command as opposed to the <u>previous</u> pipeline command?<br><br>
# Issue the '''ls''' command.<br><br>You should notice that '''no files have been created'''.<br>Let's get practice issuing more pipeline commands using commands<br>(previously learned or new) to be used as filters.<br><br>
# Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/?? | sort -r | head -5</span><br><br>What did you notice?<br><br># Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/???? | sort -r | grep r | tail -2</span><br><br>What did you notice?<br><br># Issue the following Linux '''pipeline command''': <span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/???? | sort -r | grep r | cut -c1-3</span><br><br>
# Confirm that you are still located in the '''~/redirect''' directory.<br><br>
# Issue the following Linux '''pipeline command''':<br><span style="color:blue;font-weight:bold;font-family:courier;">ls /bin/???? | tee unsort.txt | sort -r | tee sort.txt | grep r | tee match.txt | grep r | head </span><br><br>What did you notice?<br><br>
# Check the files that were created to see how the '''tee''' command was used in the previous pipeline command.<br><br>
# Issue the '''rm''' command to <u>only</u> remove the temporary files called: '''unsorted.txt''' , '''sorted.txt''' , and '''unmatched.txt'''<br><br>