Script Library¶

Scripts live in the repository under scripts/linux/ and scripts/powershell/. Each one is read-only by default, validates its input, handles errors, and documents its prerequisites and exit codes in its header.

Conventions¶

Convention	Linux (Bash)	PowerShell
Help	`./script.sh -h`	`Get-Help .\Script.ps1 -Full`
Save a report	`-o DIR`	`-OutputPath DIR`
Output format	`-f text\|csv` (where relevant)	`-Format Text\|Csv\|Json`
Exit codes	`0` OK · `1` usage error · `2` output/IO error · `3` threshold breached	same
Privileges	Runs as a normal user; reports clearly when a check needs `sudo`	Runs non-elevated; reports when a check needs Administrator

Run a script you have not written only after reading it.

Release plan¶

#	Linux	PowerShell	Purpose	Released with
1	`system-info.sh`	`System-Info.ps1`	Identity and inventory report	Day 01 (available)
2	`process-monitor.sh`	`Process-Monitor.ps1`	Top CPU/memory processes, thresholds	Day 08
3	`disk-monitor.sh`	`Disk-Monitor.ps1`	Filesystem usage with warning/critical thresholds	Day 09
4	`dns-check.sh`	`DNS-Check.ps1`	Forward/reverse lookups across resolvers	Day 13
5	`port-monitor.sh`	`Port-Monitor.ps1`	Listening ports and owning processes, baseline diff	Day 14
6	`network-diagnostic.sh`	`Network-Diagnostic.ps1`	Layered connectivity diagnosis	Day 15
7	`log-analyser.sh`	`Log-Analyser.ps1`	Error/warning summaries from system logs	Day 16
8	`failed-login-report.sh`	`Failed-Login-Report.ps1`	Failed authentication summary by account and source	Day 17
9	`system-health.sh`	`System-Health.ps1`	Thresholded health check for scheduling	Day 25
10	`daily-report.sh`	`Daily-Report.ps1`	Combined daily text and CSV report	Day 29

system-info.sh / System-Info.ps1¶

Purpose: a read-only snapshot of who/what/where: host, user, OS, kernel/build, CPU, memory, system disk, IPv4 addresses, gateway, DNS, uptime and shell version.

Prerequisites¶

Linux	Windows
Ubuntu 24.04 (any systemd distro), Bash 4+, coreutils, procps (`free`), iproute2 (`ip`). No root.	Windows 11, Windows PowerShell 5.1 or PowerShell 7. CIM access (default). No admin.

How to run¶

cd scripts/linux
bash system-info.sh                 # text report to the terminal
bash system-info.sh -f csv          # CSV (Property,Value)
bash system-info.sh -o ~/lpm-lab/reports   # also save a timestamped file

Set-Location scripts\powershell
.\System-Info.ps1                                   # requires RemoteSigned for CurrentUser
.\System-Info.ps1 -Format Json
.\System-Info.ps1 -Format Csv -OutputPath $HOME\lpm-lab\reports
# Without changing execution policy (this process only):
powershell.exe -NoProfile -ExecutionPolicy Bypass -File .\System-Info.ps1

Sample output (PowerShell 5.1, Windows 11; captured by running the script; identifying values replaced)¶

==============================================
 System Information Report
==============================================
Report time (UTC)    : 2026-11-08T10:31:47Z
Computer name        : WIN11-LAB
Current user         : WIN11-LAB\student
Operating system     : Microsoft Windows 11 Home Single Language
OS version/build     : 10.0.26200 (build 26200)
Architecture         : AMD64
Manufacturer/model   : Contoso Laptop X509
CPU model            : AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
Logical CPUs         : 8
Memory total (MB)    : 10188
Memory used (MB)     : 7646
Memory free (MB)     : 2542
System drive         : C: 96.8 GB used of 500.3 GB (19%), 403.5 GB free
IPv4 addresses       : WiFi=192.168.1.3/24
Default gateway      : 192.168.1.1 via WiFi
DNS servers          : 192.168.1.1
Uptime               : 3d 10h 34m
Boot time            : 2026-11-05 05:27:40
PowerShell           : 5.1.26100.9168 (Desktop)

Sample output (Bash, format)¶

==============================================
 System Information Report
==============================================
Report time (UTC)        : 2026-11-08T10:32:13Z
Host name                : ubuntu-lab
Current user             : student
Operating system         : Ubuntu 24.04.1 LTS
Kernel release           : 6.8.0-48-generic
Architecture             : x86_64
CPU model                : Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz
CPU cores                : 4
Load average (1/5/15)    : 0.12 0.08 0.03
Memory total             : 15990MiB
Memory used              : 1203MiB
Memory available         : 14420MiB
Root filesystem          : 31G used of 73G (43%), 42G free
IPv4 addresses           : eth0=10.1.0.4/16
Default gateway          : 10.1.0.1 via eth0
DNS servers              : 127.0.0.53
Uptime                   : up 12 minutes
Boot time                : 2026-11-08 10:20:01
Shell                    : 5.2.21(1)-release

The CI pipeline runs the script on every release on a GitHub-hosted Ubuntu 24.04 runner, and the real report is attached to each workflow run as the linux-script-reports artefact.

Troubleshooting¶

Problem	Fix
`running scripts is disabled on this system`	`Set-ExecutionPolicy -Scope CurrentUser RemoteSigned`, or use the one-off `-ExecutionPolicy Bypass -File` form
`File ... cannot be loaded. The file is not digitally signed` (downloaded zip)	`Unblock-File .\System-Info.ps1` after reading it
A field shows `n/a`	The underlying tool or query failed or is missing (for example no `ip` command in a minimal container). Run with `-Verbose` (PowerShell) to see why
`bash: ./system-info.sh: Permission denied`	Run `bash system-info.sh`, or `chmod +x system-info.sh` once
`$'\r': command not found`	The file has Windows line endings: `sed -i 's/\r$//' system-info.sh` (the repository enforces LF via `.gitattributes`)

Validation status¶

Check	Linux script	PowerShell script
Executed	CI: GitHub `ubuntu-24.04` runner, every release	Executed locally on Windows 11 / Windows PowerShell 5.1 (2026-11-08); CI: `windows-latest` with 5.1 and 7
Static analysis	`bash -n` and ShellCheck in CI	PowerShell parser and PSScriptAnalyzer in CI