Introduce cpu_frequency module

src/modules/cpu_frequency/linux.cpp

@@ -0,0 +1,47 @@
+#include <filesystem>
+
+#include "modules/cpu_frequency.hpp"
+
+std::vector<float> waybar::modules::CpuFrequency::parseCpuFrequencies() {
+  const std::string file_path_ = "/proc/cpuinfo";
+  std::ifstream info(file_path_);
+  if (!info.is_open()) {
+    throw std::runtime_error("Can't open " + file_path_);
+  }
+  std::vector<float> frequencies;
+  std::string line;
+  while (getline(info, line)) {
+    if (line.substr(0, 7).compare("cpu MHz") != 0) {
+      continue;
+    }
+
+    std::string frequency_str = line.substr(line.find(":") + 2);
+    float frequency = std::strtol(frequency_str.c_str(), nullptr, 10);
+    frequencies.push_back(frequency);
+  }
+  info.close();
+
+  if (frequencies.size() <= 0) {
+    std::string cpufreq_dir = "/sys/devices/system/cpu/cpufreq";
+    if (std::filesystem::exists(cpufreq_dir)) {
+      std::vector<std::string> frequency_files = {"/cpuinfo_min_freq", "/cpuinfo_max_freq"};
+      for (auto& p : std::filesystem::directory_iterator(cpufreq_dir)) {
+        for (auto freq_file : frequency_files) {
+          std::string freq_file_path = p.path().string() + freq_file;
+          if (std::filesystem::exists(freq_file_path)) {
+            std::string freq_value;
+            std::ifstream freq(freq_file_path);
+            if (freq.is_open()) {
+              getline(freq, freq_value);
+              float frequency = std::strtol(freq_value.c_str(), nullptr, 10);
+              frequencies.push_back(frequency / 1000);
+              freq.close();
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return frequencies;
+}