diff --git a/src/hwmon.cpp b/src/hwmon.cpp
index c3bb65d..481e9e0 100644
--- a/src/hwmon.cpp
+++ b/src/hwmon.cpp
@@ -33,10 +33,11 @@
 namespace thinkfan {
 
 
+
 static int filter_hwmon_dirs(const struct dirent *entry)
 {
 	return (entry->d_type == DT_DIR || entry->d_type == DT_LNK)
-		&& (!strncmp("hwmon", entry->d_name, 5) || !strcmp("device", entry->d_name));
+		&& (string(entry->d_name) == "hwmon" || string(entry->d_name) == "device");
 }
 
 
@@ -48,29 +49,60 @@ static int filter_subdirs(const struct dirent *entry)
 }
 
 
-template<class HwmonT>
-vector<string> HwmonInterface<HwmonT>::find_files(const string &path, const vector<unsigned int> &indices)
+template<>
+int HwmonInterface<SensorDriver>::filter_driver_file(const struct dirent *entry)
+{
+	int idx;
+	return (entry->d_type == DT_REG || entry->d_type == DT_LNK)
+		&& ::sscanf(entry->d_name, "temp%d_input", &idx) == 1
+	;
+}
+
+template<>
+int HwmonInterface<FanDriver>::filter_driver_file(const struct dirent *entry)
+{
+	int idx;
+	return (entry->d_type == DT_REG || entry->d_type == DT_LNK)
+		&& ::sscanf(entry->d_name, "pwm%d", &idx) == 1
+	;
+}
+
+
+template<int (* filter_fn)(const struct dirent *)>
+vector<string> dir_entries(const filesystem::path &dir)
 {
+	struct dirent **entries;
+	int nentries = ::scandir(dir.c_str(), &entries, filter_fn, nullptr);
+	if (nentries == -1)
+		return {};
+
 	vector<string> rv;
-	for (unsigned int idx : indices) {
-		const string fpath(path + "/" + filename(idx));
-		std::ifstream f(fpath);
-		if (f.is_open() && f.good())
-			rv.push_back(fpath);
-		else
-			throw IOerror("Can't find hwmon file: " + fpath, errno);
+	for (int i = 0; i < nentries; ++i) {
+		rv.emplace_back(dir / entries[i]->d_name);
+		::free(entries[i]);
 	}
+	::free(entries);
 	return rv;
 }
 
-template<>
-string HwmonInterface<SensorDriver>::filename(unsigned int index)
-{ return "temp" + std::to_string(index) + "_input"; }
 
 template<>
-string HwmonInterface<FanDriver>::filename(unsigned int index)
+string HwmonInterface<FanDriver>::filename_by_index(unsigned int index)
 { return "pwm" + std::to_string(index); }
 
+template<>
+string HwmonInterface<SensorDriver>::filename_by_index(unsigned int index)
+{ return "temp" + std::to_string(index) + "_input"; }
+
+
+template<class HwmonT>
+vector<string> HwmonInterface<HwmonT>::filenames_by_indices(const vector<unsigned int> &indices)
+{
+	vector<string> rv;
+	for (unsigned int index : indices)
+		rv.push_back(filename_by_index(index));
+	return rv;
+}
 
 
 template<class HwmonT>
@@ -85,16 +117,17 @@ HwmonInterface<HwmonT>::HwmonInterface(const string &base_path, opt<const string
 , indices_(indices)
 {}
 
+
 template<class HwmonT>
 vector<string> HwmonInterface<HwmonT>::find_hwmons_by_name(
-	const string &path,
+	const filesystem::path &path,
 	const string &name,
 	unsigned char depth
 ) {
 	const unsigned char max_depth = 5;
 	vector<string> result;
 
-	ifstream f(path + "/name");
+	ifstream f(path / "name");
 	if (f.is_open() && f.good()) {
 		string tmp;
 		if ((f >> tmp) && tmp == name) {
@@ -106,15 +139,7 @@ vector<string> HwmonInterface<HwmonT>::find_hwmons_by_name(
 		return result;  // don't recurse to subdirs
 	}
 
-	struct dirent **entries;
-	int nentries = ::scandir(path.c_str(), &entries, filter_subdirs, nullptr);
-	if (nentries == -1) {
-		return result;
-	}
-	for (int i = 0; i < nentries; i++) {
-		auto subdir = path + "/" + entries[i]->d_name;
-		free(entries[i]);
-
+	for (const auto &subdir : dir_entries<filter_subdirs>(path)) {
 		struct stat statbuf;
 		int err = stat(path.c_str(), &statbuf);
 		if (err || (statbuf.st_mode & S_IFMT) != S_IFDIR)
@@ -123,21 +148,21 @@ vector<string> HwmonInterface<HwmonT>::find_hwmons_by_name(
 		auto found = find_hwmons_by_name(subdir, name, depth + 1);
 		result.insert(result.end(), found.begin(), found.end());
 	}
-	free(entries);
 
 	return result;
 }
 
+
 template<class HwmonT>
 vector<string> HwmonInterface<HwmonT>::find_hwmons_by_model(
-	const string &path,
+	const filesystem::path &path,
 	const string &model,
 	unsigned char depth
 ) {
 	const unsigned char max_depth = 5;
 	vector<string> result;
 
-	ifstream f(path + "/model");
+	ifstream f(path / "model");
 	if (f.is_open() && f.good()) {
 		string tmp;
 		if (getline(f, tmp)) {
@@ -152,15 +177,7 @@ vector<string> HwmonInterface<HwmonT>::find_hwmons_by_model(
 		return result; // don't recurse to subdirs
 	}
 
-	struct dirent **entries;
-	int nentries = ::scandir(path.c_str(), &entries, filter_subdirs, nullptr);
-	if (nentries == -1) {
-		return result;
-	}
-	for (int i = 0; i < nentries; i++) {
-		auto subdir = path + "/" + entries[i]->d_name;
-		free(entries[i]);
-
+	for (const auto &subdir : dir_entries<filter_subdirs>(path)) {
 		struct stat statbuf;
 		int err = stat(path.c_str(), &statbuf);
 		if (err || (statbuf.st_mode & S_IFMT) != S_IFDIR)
@@ -169,52 +186,57 @@ vector<string> HwmonInterface<HwmonT>::find_hwmons_by_model(
 		auto found = find_hwmons_by_model(subdir, model, depth + 1);
 		result.insert(result.end(), found.begin(), found.end());
 	}
-	free(entries);
 
 	return result;
 }
 
+
 template<class HwmonT>
 vector<string> HwmonInterface<HwmonT>::find_hwmons_by_indices(
-	const string &path,
+	const filesystem::path &path,
 	const vector<unsigned int> &indices,
 	unsigned char depth
 ) {
 	constexpr unsigned char max_depth = 3;
 
-	try {
-		return find_files(path, indices);
+	vector<string> rv;
+	vector<string> filenames = filenames_by_indices(indices);
+	for (const filesystem::path fname : filenames) {
+		const filesystem::path fpath(path / fname);
+		std::ifstream f(fpath);
+		if (f.is_open() && f.good())
+			rv.push_back(fpath);
+		else if (rv.size()) // Found one, but another is missing: Error
+			throw IOerror("Can't find hwmon file: " + string(fpath), errno);
 	}
-	catch (IOerror &) {
+
+	if (rv.empty()) { // No matching files in this directory
 		if (depth <= max_depth) {
-			struct dirent **entries;
-			int nentries = ::scandir(path.c_str(), &entries, filter_hwmon_dirs, alphasort);
-			if (nentries < 0)
-				throw IOerror("Error scanning " + path + ": ", errno);
+			vector<string> hwmon_dirs = dir_entries<filter_hwmon_dirs>(path);
+			if (hwmon_dirs.empty())
+				return {};
 
-			vector<string> rv;
-			for (int i = 0; i < nentries; i++) {
+			for (const auto &hwmon_dir : hwmon_dirs) {
 				rv = HwmonInterface<HwmonT>::find_hwmons_by_indices(
-					path + "/" + entries[i]->d_name,
+					hwmon_dir,
 					indices,
 					depth + 1
 				);
 				if (rv.size())
-					break;
+					return rv;
 			}
-			for (int i = 0; i < nentries; i++)
-				free(entries[i]);
-			free(entries);
 
-			return rv;
+			if (depth == 0) // Nothing found here or after recursion
+				throw DriverInitError(
+					"Could not find requested files " + vec_to_string(filenames)
+					 + " in " + string(path) + "."
+				);
 		}
-		else
-			throw DriverInitError("Could not find an `hwmon*' directory or `temp*_input' file in " + path + ".");
 	}
+	return rv;
 }
 
 
-
 template<class HwmonT>
 string HwmonInterface<HwmonT>::lookup()
 {
@@ -229,7 +251,7 @@ string HwmonInterface<HwmonT>::lookup()
 			if (paths.size() != 1) {
 				string msg(path + ": ");
 				if (paths.size() == 0) {
-					msg += "Could not find a hwmon with this name: " + name_.value();
+					msg += "Could not find an hwmon with this name: " + name_.value();
 				} else {
 					msg += MSG_MULTIPLE_HWMONS_FOUND;
 					for (string hwmon_path : paths)
@@ -259,8 +281,10 @@ string HwmonInterface<HwmonT>::lookup()
 			if (found_paths_.size() == 0)
 				throw DriverInitError(path + ": " + "Could not find any hwmons in " + path);
 		}
-		else
-			found_paths_.push_back(path);
+		else {
+			vector<string> paths = dir_entries<filter_driver_file>(path);
+			found_paths_.swap(paths);
+		}
 
 		paths_it_.emplace(found_paths_.begin());
 	}
diff --git a/src/hwmon.h b/src/hwmon.h
index 92e3b1f..fc7e64b 100644
--- a/src/hwmon.h
+++ b/src/hwmon.h
@@ -24,6 +24,7 @@
 #include "thinkfan.h"
 
 #include <dirent.h>
+#include <filesystem>
 
 namespace thinkfan {
 
@@ -31,6 +32,8 @@ namespace thinkfan {
 class HwmonSensorDriver;
 class HwmonFanDriver;
 
+namespace filesystem = std::filesystem;
+
 
 template<class HwmonT>
 class HwmonInterface {
@@ -41,12 +44,14 @@ class HwmonInterface {
 	string lookup();
 
 private:
-	static vector<string> find_files(const string &path, const vector<unsigned int> &indices);
-	static string filename(unsigned int index);
+	static int filter_driver_file(const struct dirent *entry);
+	static string filename_by_index(unsigned int index);
+	static vector<string> filenames_by_indices(const vector<unsigned int> &indices);
+
+	static vector<string> find_hwmons_by_model(const filesystem::path &path, const string &model, unsigned char depth);
+	static vector<string> find_hwmons_by_name(const filesystem::path &path, const string &name, unsigned char depth);
+	static vector<string> find_hwmons_by_indices(const filesystem::path &path, const vector<unsigned int> &indices, unsigned char depth);
 
-	static vector<string> find_hwmons_by_model(const string &path, const string &model, unsigned char depth);
-	static vector<string> find_hwmons_by_name(const string &path, const string &name, unsigned char depth);
-	static vector<string> find_hwmons_by_indices(const string &path, const vector<unsigned int> &indices, unsigned char depth);
 
 protected:
 	opt<const string> base_path_;
diff --git a/src/message.h b/src/message.h
index df61ba8..99a4625 100644
--- a/src/message.h
+++ b/src/message.h
@@ -106,6 +106,32 @@ template<class ErrT, class... ArgTs> void error(const ArgTs &... args) {
 }
 
 
+template<class T>
+string to_string(const T &);
+
+
+template<>
+string to_string(const string &s)
+{ return s; }
+
+template<class T>
+string to_string(const T &o)
+{ return std::to_string(o); }
+
+
+template<class T>
+string vec_to_string(const vector<T> &v)
+{
+	string rv = "[";
+	for (const T& item : v)
+		rv += to_string(item) + ", ";
+	if (rv.length() > 2)
+		rv = rv.substr(0, rv.length() - 2);
+	rv += "]";
+	return rv;
+}
+
+
 } // namespace thinkfan