Lab 02: Project Workspace

Field	Value
Lab ID	LAB-02
Related lesson	Day 02: File and Directory Management
Difficulty	Beginner
Time	60–75 minutes
Risk level	Low. All changes stay inside ~/lab02. Do not run any command outside that folder.

Objective

Create a standard project workspace, populate it with sample files, take a correct backup, reorganise files with wildcards, and perform a safe, previewed cleanup in both Bash and PowerShell.

Required Environment

• Ubuntu 24.04 LTS terminal (normal user) and/or Windows 11 PowerShell (5.1 or 7, not elevated).
• About 1 MB free disk space.

Initial Conditions

• ~/lab02 (Linux) / $HOME\lab02 (Windows) must not exist. Check first:
  • Bash: ls -d ~/lab02 should report No such file or directory.
  • PowerShell: Test-Path $HOME\lab02 should return False.
• If it exists from an earlier attempt, rename it (mv ~/lab02 ~/lab02.old) rather than deleting it.

Step-by-Step Instructions

1. Create the tree lab02/webapp/{config,logs,src,docs} plus lab02/backups, using one command per shell.
2. Create files:
   • config/app.conf, config/db.conf
   • logs/access-2026-11-01.log, logs/access-2026-11-02.log, logs/error-2026-11-02.log, logs/debug.tmp, logs/cache.tmp
   • src/main.sh (Linux) / src/Main.ps1 (Windows)
   • docs/README.txt containing the text Webapp documentation
3. Back up the config folder to backups/config-YYYY-MM-DD (today's date) so that the backup folder directly contains app.conf and db.conf, not a nested config folder.
4. Reorganise logs: create logs/archive and move only the access-* logs from 2026-11-01 into it.
5. Rename docs/README.txt to docs/README.md.
6. Preview and then delete all *.tmp files in logs.
7. Attempt to remove webapp/src with the "only if empty" command and observe that it refuses.
8. Display the final tree.

Commands to Execute

Try each step yourself first. Commands are in the Solution.

Expected Results

Final structure (both platforms, apart from the script file name):

lab02
├── backups
│   └── config-2026-11-08
│       ├── app.conf
│       └── db.conf
└── webapp
    ├── config
    │   ├── app.conf
    │   └── db.conf
    ├── docs
    │   └── README.md
    ├── logs
    │   ├── access-2026-11-02.log
    │   ├── archive
    │   │   └── access-2026-11-01.log
    │   └── error-2026-11-02.log
    └── src
        └── main.sh

Verification Steps

BashPowerShell

cd ~/lab02
find . | sort
ls webapp/logs/*.tmp 2>/dev/null | wc -l          # expect 0
ls backups/config-*/                               # expect app.conf db.conf
cat webapp/docs/README.md                          # expect "Webapp documentation"

Set-Location $HOME\lab02
Get-ChildItem -Recurse | Select-Object -ExpandProperty FullName | Sort-Object
(Get-ChildItem webapp\logs -Filter *.tmp).Count    # expect 0
Get-ChildItem backups\config-* | Get-ChildItem -Name   # expect app.conf db.conf
Get-Content webapp\docs\README.md                  # expect "Webapp documentation"

Troubleshooting

Symptom	Cause	Fix
Backup contains config-.../config/app.conf	Destination folder already existed when you copied the directory	Delete that backup folder (preview first) and copy the contents: cp -r webapp/config/. backups/config-$(date +%F)/
mv: cannot stat 'webapp/logs/access-2026-11-01*'	Wrong directory or typo	pwd; use tab completion
PowerShell Rename-Item error about the path	-NewName given a path	Use only README.md as the new name
rmdir succeeded on src	src was empty because step 2 was skipped	Recreate the file and repeat step 7
Files show up in C:\Windows\System32	You opened an elevated PowerShell, which starts there	Close it; use a normal window; Set-Location ~

Questions

1. Why did step 3 require copying the folder's contents?
2. What would have happened in step 6 if you had typed rm logs/*.tmp * by accident? How does previewing protect you?
3. Why does rmdir (and Remove-Item without -Recurse) refuse to delete src, and why is that useful?
4. Which PowerShell parameter showed you what would be deleted without deleting it?
5. How would you make step 1 safe to run twice?

Solution

Bash solution

# 1. tree (idempotent)
mkdir -p ~/lab02/webapp/{config,logs,src,docs} ~/lab02/backups
cd ~/lab02/webapp

# 2. files
touch config/{app,db}.conf
touch logs/access-2026-11-0{1,2}.log logs/error-2026-11-02.log logs/{debug,cache}.tmp
touch src/main.sh
echo "Webapp documentation" > docs/README.txt

# 3. backup the CONTENTS of config into a dated folder
backup_dir=~/lab02/backups/config-$(date +%F)
mkdir -p "$backup_dir"
cp -av config/. "$backup_dir"/

# 4. reorganise logs
mkdir -p logs/archive
mv -v logs/access-2026-11-01*.log logs/archive/

# 5. rename
mv -v docs/README.txt docs/README.md

# 6. preview, then delete
ls logs/*.tmp
rm -iv logs/*.tmp

# 7. refuses because src is not empty
rmdir src          # rmdir: failed to remove 'src': Directory not empty

# 8. final tree
cd ~/lab02 && (tree 2>/dev/null || find . | sort)

PowerShell solution

# 1. tree (idempotent with -Force for directories)
$base = Join-Path $HOME 'lab02'
'webapp\config','webapp\logs','webapp\src','webapp\docs','backups' |
    ForEach-Object { New-Item -Path (Join-Path $base $_) -ItemType Directory -Force | Out-Null }
Set-Location (Join-Path $base 'webapp')

# 2. files
'config\app.conf','config\db.conf',
'logs\access-2026-11-01.log','logs\access-2026-11-02.log','logs\error-2026-11-02.log',
'logs\debug.tmp','logs\cache.tmp','src\Main.ps1' |
    ForEach-Object { New-Item -Path $_ -ItemType File | Out-Null }
New-Item -Path docs\README.txt -ItemType File -Value 'Webapp documentation' | Out-Null

# 3. backup the CONTENTS of config
$backupDir = Join-Path $base ("backups\config-{0}" -f (Get-Date -Format 'yyyy-MM-dd'))
New-Item -Path $backupDir -ItemType Directory -Force | Out-Null
Copy-Item -Path config\* -Destination $backupDir -PassThru | Select-Object Name

# 4. reorganise logs
New-Item -Path logs\archive -ItemType Directory -Force | Out-Null
Move-Item -Path logs\access-2026-11-01*.log -Destination logs\archive -PassThru

# 5. rename (name only, not a path)
Rename-Item -Path docs\README.txt -NewName README.md

# 6. preview, simulate, delete
Get-ChildItem logs -Filter *.tmp
Remove-Item -Path logs\*.tmp -WhatIf
Remove-Item -Path logs\*.tmp

# 7. Remove-Item on a non-empty folder without -Recurse asks for confirmation. Answer N.
Remove-Item -Path src

# 8. final tree
Set-Location $base
Get-ChildItem -Recurse | Select-Object -ExpandProperty FullName

Answers to questions

1. The backup folder already existed (we created it first). Copying a directory into an existing directory nests it. Copying config/. (Bash) or config\* (PowerShell) copies only the contents.
2. The extra * would expand to every file in the current directory, and rm would delete them all. Running ls with the exact same pattern first shows the full list before anything is deleted.
3. They only remove empty directories by default. That makes cleanup safe: if something unexpected is inside, nothing is lost.
4. -WhatIf.
5. Use mkdir -p / New-Item -ItemType Directory -Force. Both succeed silently if the directories already exist.

Clean-up (optional)

ls -R ~/lab02 && rm -rI ~/lab02

Remove-Item $HOME\lab02 -Recurse -WhatIf
Remove-Item $HOME\lab02 -Recurse