memory: port parseMeminfo to BSDs

src/modules/memory/linux.cpp

@@ -0,0 +1,20 @@
+#include "modules/memory.hpp"
+
+void waybar::modules::Memory::parseMeminfo() {
+  const std::string data_dir_ = "/proc/meminfo";
+  std::ifstream info(data_dir_);
+  if (!info.is_open()) {
+    throw std::runtime_error("Can't open " + data_dir_);
+  }
+  std::string line;
+  while (getline(info, line)) {
+    auto posDelim = line.find(':');
+    if (posDelim == std::string::npos) {
+      continue;
+    }
+
+    std::string name = line.substr(0, posDelim);
+    int64_t     value = std::stol(line.substr(posDelim + 1));
+    meminfo_[name] = value;
+  }
+}