Introduction

Welcome to the Survival Guide for the sed command. You have been dropped into a server with "realistic" system files and data.

• Configuration files are in /home/laborant/sed_challenge/config/.
• Log files are in /home/laborant/sed_challenge/logs/.
• Data files are in /home/laborant/sed_challenge/data/.

Your mission is to perform 10 essential sed tasks ranging from basic substitution to advanced hold space techniques.

Before you jump into your favorite AI chatbot, try to solve these tasks using the manual pages man sed and experimenting, believe me its really worth it, even in AI era !

Man pages tips :

• Use / to search inside the man pages.
• Search for keywords like "substitution", "address", "in-place", "regex", etc.
• Press n to go to the next occurrence of your search term, or N to go to the previous occurrence.
• Press q to quit the

There is a cheatsheet available in solution page, but writing your own is worth it!

Task 1: Simple Substitution

File: /home/laborant/sed_challenge/config/network.conf.

Goal: Replace the first occurrence of dhcp with static in the file.

Save to /home/laborant/q1_network.txt.

Task 2: Global Substitution

File: /home/laborant/sed_challenge/data/services.txt.

Goal: Replace ALL occurrences of tcp with TCP (uppercase).

Save to /home/laborant/q2_services.txt.

Task 3: Regex & Metacharacters

File: /home/laborant/sed_challenge/config/hosts.conf.

Goal: Modify IP addresses that start with 10.0.1 to start with 10.0.10.

Example: 10.0.1.10 → 10.0.10.10

Save to /home/laborant/q3_hosts.txt.

Task 4: Line Ranges

File: /home/laborant/sed_challenge/logs/system.log.

Goal: Extract ONLY lines 5 to 10 from the log file.

Save to /home/laborant/q4_filtered.txt.

Task 5: Line Deletion

File: /home/laborant/sed_challenge/logs/application.log.

Goal: Delete ALL lines containing the word DEBUG.

Save to /home/laborant/q5_clean.log.

Task 6: Line Insertion

File: /home/laborant/sed_challenge/config/hosts.conf.

Goal: Insert the line # Welcom to Iximiuz BEFORE the line containing # Production Servers.

Save to /home/laborant/q6_modified.txt.

Task 7: Multi-commands

File: /home/laborant/sed_challenge/logs/system.log.

Goal: Perform these 3 operations in a single command:

1. Replace ERROR with CRITICAL
2. Replace WARNING with WARN
3. Delete all lines containing INFO

Save to /home/laborant/q7_transformed.txt.

Phase 3: Advanced Techniques

Task 8: In-Place Editing

File: /home/laborant/sed_challenge/config/network.conf.

Goal: Modify the file DIRECTLY by replacing ONBOOT=no with ONBOOT=yes.

⚠️ WARNING: Create a backup with the .backup extension before modification!

Task 9: Alternate Delimiter

File: /home/laborant/sed_challenge/data/users.txt.

Goal: Replace every /bin/bash with /bin/zsh using a different delimiter (for example .) to avoid escaping /.

Save to /home/laborant/q9_shells.txt.

Task 10: Filter by Pattern

File: /home/laborant/sed_challenge/data/services.txt.

Goal: Extract only comment lines (those starting with #) and discard everything else.

Save to /home/laborant/q10_comments.txt.

Good luck! 🚀