Description
Purpose: Practices on the grep family commands to process texts in files.
Open your terminal and connect to snowball server. Change your directory to your home directory (cd ~ ), and then create a new directory named as “Lab4” (mkdir Lab4). After that, go to directory Lab4 (cd Lab4) and please download the file “CSC_Course.txt” by the following command (internet access required):
cp /home/frondel/Public/CSC_Course.txt CSC_Course.txt
Be sure it succeeds using “ls” to see the file name “CSC_Course.txt” listed.
Try the following commands step by step and finish the required tasks from step 4) to step 16).
Note: marks a single space.
- $more txt
Check the content of “CSC_Course.txt” using more.
Note: When viewing the file, you may need to use command f (forward one screen), b (backward one screen) and q(quit).
- $grep ‘CSC 3320’ CSC_Course.txt
Note: there is a single space between “CSC” and “3320”
Output the lines containing the string “CSC 3320″(search the course the number of which is “CSC 3320”)
- $grep -i ‘CSC 3320’ CSC_Course.txt
Output the lines containing the string “CSC 3320” via ignoring case (search the information related to CSC3320)
- $ grep ‘CSC 3’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
1
- $ grep ‘CSC 3|CSC 1’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
- $ grep -E ‘CSC 3|CSC 1’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
Use extend regular expression
- $ egrep ‘CSC 3|CSC 1’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
- $ fgrep ‘3.000 Credit hours’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
- $ fgrep -x ‘3.000 Credit hours’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
Only match the whole line
- $ grep ‘CSC.*Programming’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
- $ grep ‘^CSC.*Programming$’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
- $ grep –color ‘CSC[^3]*3{2}’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
No result, {} is not a special character
13) $ egrep –color -w ‘CSC[^3]*3{2}[^3]*’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
-w Select only those lines containing matches that form whole words.
14) $ grep ‘CSC.*C++’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
+ is not a special character in basic regular expression
- $ egrep ‘CSC.*C\+\+’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does. Convert +
- $ egrep ‘CSC.*C++’ CSC_Course.txt
Please only describe what this command does.
Optional Part:
1) $ sed -E -n ‘s/(CSC 3[0-9]{3})(.*)/\1/p’ CSC_Course.txt
Attach a screenshot of the output and describe what this command does.
2)$ awk -F’-‘ ‘/(CSC 3[0-9]{3})(.*)/{print $1}’ CSC_Course.txt Attach a screenshot of the output and describe what this command does.
- $ sed -E -n ‘s/(CSC [0-9]{4})( – )(.*)/\3/p’ txt
Attach a screenshot of the output and describe what this command does.
- $ sed -E -n ‘s/(CSC [0-9]{4})( – )(.*)/\3/p’ CSC_Course.txt| sort
Attach a screenshot of the output and describe what this command does.
