Add a disk module

src/util/format.cpp

@@ -0,0 +1,26 @@
+#include <sstream>
+
+namespace waybar::util {
+
+std::string pow_format(unsigned long long value, const std::string &unit, bool binary = false) {
+  auto base = binary ? 1024ull : 1000ull;
+  const char* units[] = { "", "k",  "M",  "G",  "T",  "P",  nullptr};
+  auto fraction = (double) value;
+
+  int pow;
+  for (pow = 0; units[pow+1] != nullptr && fraction / base >= 2; ++pow) {
+    fraction /= base;
+  }
+
+  std::ostringstream ss;
+  if (pow > 0) {
+    auto quotient = (unsigned long long) fraction;
+    auto remainder = (unsigned long long) ((fraction - quotient) * 10);
+    ss << quotient << "." << remainder << units[pow] << (binary ? "i" : "") << unit;
+  } else {
+    ss << value << unit;
+  }
+  return ss.str();
+};
+
+}