Lab Information
There is some data on Nautilus App Server 2 in Stratos DC. Data needs to be altered in several of the files. On Nautilus App Server 2, alter the /home/BSD.txt file as per details given below:
a. Delete all lines containing word software and save results in /home/BSD_DELETE.txt file. (Please be aware of case sensitivity)
b. Replace all occurrence of word from to is and save results in /home/BSD_REPLACE.txt file.
Note: Let's say you are asked to replace word to with from. In that case, make sure not to alter any words containing the string itself; for example upto, contributor etc.
Lab Solutions
🧭 Part 1: Lab Step-by-Step Guidelines
Objective
Modify the file:
/home/BSD.txt
on App Server 2 (stapp02) and create two output files.
Task Output File
Remove lines containing software /home/BSD_DELETE.txt
Replace from → is /home/BSD_REPLACE.txt
1️⃣ Login to Jump Host
ssh thor@jump_host.stratos.xfusioncorp.com
Password:
mjolnir123
2️⃣ SSH into App Server 2
ssh steve@stapp02
Password:
Am3ric@
3️⃣ Delete lines containing the word software
Use grep with -v (invert match).
sudo -i
grep -v software /home/BSD.txt > /home/BSD_DELETE.txt
Explanation:
Option Meaning
grep search text
-v exclude matching lines
software target word
4️⃣ Replace the word from → is
Use sed with word boundaries.
sed 's/\bfrom\b/is/g' /home/BSD.txt > /home/BSD_REPLACE.txt
5️⃣ Verify the files
Check they exist:
ls /home
Expected files:
BSD.txt
BSD_DELETE.txt
BSD_REPLACE.txt
🧠 Part 2: Simple Step-by-Step Explanation (Beginner Friendly)
What this lab tests
This lab checks your ability to use Linux text-processing commands:
Tool Purpose
grep search/filter lines
sed edit or replace text
These are very common DevOps commands.
Task A — Remove lines containing software
Command:
grep -v software /home/BSD.txt > /home/BSD_DELETE.txt
Meaning:
Part Meaning
grep search command
-v exclude matching lines
software lines containing this word
save output to a file
So the command means:
Take BSD.txt
Remove lines containing "software"
Save result to BSD_DELETE.txt
Task B — Replace from with is
Command:
sed 's/\bfrom\b/is/g' /home/BSD.txt
Breakdown:
Part Meaning
sed stream editor
s substitute
from word to replace
is new word
g replace all occurrences
Why we use \b (word boundaries)
The lab warns about this:
do not replace inside words like:
upto
contributor
Without boundaries:
sed 's/from/is/g'
This might incorrectly change parts of other words.
Using boundaries:
sed 's/\bfrom\b/is/g'
ensures only the exact word is replaced.
Top comments (0)