feat(lib): shell: +check-tool

lib/default.nix

@@ -48,7 +48,10 @@ in {
   forSystems = systems: nixpkgs.lib.genAttrs systems;
   forAllSystems = nixpkgs.lib.genAttrs commonSystems;
 
-  shellModules.logs = builtins.readFile ./shell/logs.sh;
+  shellModules = {
+    logs = builtins.readFile ./shell/logs.sh;
+    check-tool = builtins.readFile ./shell/check-tool.sh;
+  };
 
   sharedShellAliases = {
     jc = ''journalctl'';

lib/shell/check-tool.sh

@@ -0,0 +1,6 @@
+check_tool() {
+  if ! command -v "$1" >/dev/null; then
+    echo "Required tool \`$2\` are not installed or binary \`$1\` not found." >&2
+    exit 1
+  fi
+}