add "system" path

Author: Skycoder42

README.md

@@ -29,7 +29,9 @@ repkg create <package> [dependencies...]
 ```
 `package` is the AUR package that should be rebuild, when one of the given `dependencies` is updated to a newer versions. You can also create rules directly by creating a rule file in `~/.config/repkg/rules`, with the package name beeing the filename (i.e. `package.rule`) and the content beeing the dependencies, space seperated.
 
-When updating packages via pacman (or any frontend), rebuilds are automatically detected. You will see a message with all packages that need rebuilds at the end. You can also run 
+For system admins, when running this command as root, the rules are instead written to `/etc/repkg/rules`. For repkg prior to version `1.3.0` this will overwrite the rules created by installed packages. But since `1.3.0` packages should place their rules in `/etc/repkg/rules/system` to prevent such conflicts.
+
+When updating packages via pacman (or any frontend), rebuilds are automatically detected. You will see a message with all packages that need rebuilds at the end. You can also run
 ```
 repkg list detail
 ```
@@ -42,7 +44,7 @@ repkg
 This will start the frontend of your choice (e.g. yay, trizen, pacaur, yaourt, ...) and rebuild all required packages. 
 
 ### Package Providers
-Simply add a rule file to your PKGBUILD, and install it to `/etc/repkg/rules`. Assuming your package is name `my-pkg` and should be rebuild when `dep-a` or `dep-b` is updated, the file must be named `my-pkg.rule` and contain:
+Simply add a rule file to your PKGBUILD, and install it to `/etc/repkg/rules/system` (or `/etc/repkg/rules` if you want to be compatible with versions of repkg before `1.3.0`). Assuming your package is name `my-pkg` and should be rebuild when `dep-a` or `dep-b` is updated, the file must be named `my-pkg.rule` and contain:
 ```
 dep-a dep-b
 ```

global.cpp

@@ -27,7 +27,7 @@ QDir global::userPath()
 	if(dir.exists())
 		return dir;
 	else
-		return QDir();
+		return {};
 }
 
 QDir global::rootPath()
@@ -39,5 +39,14 @@ QDir global::rootPath()
 	if(dir.exists())
 		return dir;
 	else
-		return QDir();
+		return {};
+}
+
+QDir global::systemPath()
+{
+	QDir dir{rootPath()};
+	if(dir.cd(QStringLiteral("system")))
+		return dir;
+	else
+		return {};
 }

global.h

@@ -11,6 +11,7 @@ bool isRoot();
 
 QDir userPath();
 QDir rootPath();
+QDir systemPath();
 }
 
 #endif // GLOBAL_H

rulecontroller.cpp

@@ -96,7 +96,8 @@ void RuleController::readRules() const
 {
 	QList<std::pair<QDir, bool>> paths {
 		{userPath(), false},
-		{rootPath(), true}
+		{rootPath(), true},
+		{systemPath(), true},
 	};
 
 	_ruleInfos.clear();