Re-write README.md; unify installation scripts

README.md

@@ -2,15 +2,34 @@
 A shell script and systemd service unit file to ensure overscan is disabled
 on Raspberry Pis running Debian-based systems.
 
-## Overview
-This simply does what it says on the tin. The shell script `check-overscan.sh` does the "hard"
-work of iterating over the lines of `/boot/firmware/config.txt` and adding
-`disable_overscan=1` if it's not found. The unit file `check-overscan.service`
-just tells systemd that we want to run this check on poweroff or reboot, as
-vanilla Debian overwrites `config.txt` on kernel upgrades.
+## What
+The contents of this directory are simply:
+* `check-overscan`: a shell script to check if `disable_overscan=1` is in the Raspberry Pi's
+`config.txt` file and add it if it isn't
+* `check-overscan.service`: a systemd unit file to run `check-overscan.sh` at shutdown or reboot
+* `install.sh`: a shell script to install and enable the script and service, as well as disable
+and uninstall them (in that order)
+* `README.md`: this document
 
-## Installation
-You should be able to simply run `install.sh` with privileges (eg `sudo sh install.sh`) and everything
-will be done for you. Note that this has not been tested anywhere but vanilla
-Debian arm64 using Raspberry Pi 4-compatible images. `uninstall.sh` will simply remove the files and disable the service.
+## Why
+On the vanilla Debian arm64 Raspberry Pi image, updating the kernel overwrites any changes
+made to `config.txt`. This script and service make sure you don't forget to add back
+`disable_overscan=1`.
 
+## How (Usage)
+To install the service, simply download this repository (such as cloning it with git), enter it,
+and run `install.sh`.
+```
+git clone https://github.com/Marie-Joseph/rpi-check-overscan.git
+cd rpi-check-overscan
+sh install.sh
+```
+To uninstall it, simply run `install.sh` again with `--uninstall` or `-u`.
+```
+cd rpi-check-overscan
+sh install.sh --uninstall
+```
+
+Note that on Raspberry Pi OS, the Raspberry Pi Foundation's spin of Debian, the
+path to `config.txt` is slightly different. For these cases, simply edit the
+path for `configFile` in `check-overscan.sh` with a text editor.

check-overscan

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-configFile="/boot/firmware/config.txt"
+configFile="/boot/firmware/config.txt";
 
 if [ ! $(awk '/disable_overscan=1/ { print("1") }' $configFile) ]; then
     echo "disable_overscan=1" >> $configFile;

check-overscan.service

@@ -5,7 +5,7 @@ Before=shutdown.target reboot.target
 
 [Service]
 Type=oneshot
-ExecStart=/usr/bin/check-overscan.sh
+ExecStart=/usr/bin/check-overscan
 TimeoutStartSec=0
 
 [Install]

install.sh

@@ -2,16 +2,28 @@
 
 systemdDir="/lib/systemd/system"
 binDir="/bin"
-script="check-overscan.sh"
+script="check-overscan"
 service="check-overscan.service"
 
-systemctl daemon-reload
-echo -n "Installing $script... "
-cp $script $binDir/
-chmod +x $binDir/$script
-echo "Done."
+if [ $1 = "-u" ] || [ $1 = "--uninstall" ]; then
+    echo -n "Uninstalling $service... ";
+    systemctl disable $service;
+    rm $systemdDir/$service;
+    systemctl daemon-reload;
+    echo "Done.";
 
-echo -n "Installing $service... "
-cp $service $systemdDir/
-systemctl enable $service
-echo "Done."
+    echo -n "Uninstalling $script... ";
+    rm $binDir/$script;
+    echo "Done.";
+else
+    echo -n "Installing $script... ";
+    cp $script $binDir/;
+    chmod +x $binDir/$script;
+    echo "Done.";
+
+    echo -n "Installing $service... ";
+    cp $service $systemdDir/;
+    systemctl daemon-reload;
+    systemctl enable $service;
+    echo "Done.";
+fi;

uninstall.sh

@@ -1,9 +0,0 @@
-#!/bin/sh
-
-script="/bin/check-overscan.sh"
-service="check-overscan.service"
-systemdDir="/lib/systemd/system"
-
-systemctl disable $service
-rm $script $systemdDir/$service
-systemctl daemon-reload