Use ifstream to reaad /proc/meminfo

include/modules/memory.hpp

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <fmt/format.h>
-#include <stdio.h>
+#include <fstream>
 #include "util/chrono.hpp"
 #include "ALabel.hpp"
 

src/modules/memory.cpp

@@ -14,28 +14,56 @@ waybar::modules::Memory::Memory(const Json::Value& config)
 auto waybar::modules::Memory::update() -> void
 {
   parseMeminfo();
+  if(memtotal_ > 0 && memfree_ >= 0) {
     int used_ram_percentage = 100 * (memtotal_ - memfree_) / memtotal_;
     label_.set_text(fmt::format(format_, used_ram_percentage));
     auto used_ram_gigabytes = (memtotal_ - memfree_) / std::pow(1024, 2);
     label_.set_tooltip_text(fmt::format("{:.{}f}Gb used", used_ram_gigabytes, 1));
+    label_.show();
+  } else {
+    label_.hide();
+  }
 }
 
 void waybar::modules::Memory::parseMeminfo()
 {
-  int memtotal, memfree, memavail, membuffer, memcache;
-  FILE* info = fopen("/proc/meminfo","r");
-  if(fscanf (info, "MemTotal: %d kB MemFree: %d kB Buffers: %d kB Cached: %d kB",&memtotal, &memfree, &membuffer, &memcache) < 4) { // Old meminfo format 
-    rewind(info);
-    if(fscanf(info, "MemTotal: %d kB MemFree: %d kB MemAvailable: %d kB Buffers: %d kB Cached: %d kB",&memtotal, &memfree, &memavail, &membuffer, &memcache) < 5) { // Current meminfo format
-      memtotal_ = -1;
-      memfree_ = -1;
-    } else {
-      memtotal_ = memtotal;
-      memfree_ = memavail;
+  long memtotal = -1, memfree = -1, membuffer = -1, memcache = -1, memavail = -1;
+  int count = 0;
+  std::string line;
+  std::ifstream info("/proc/meminfo");
+  if(info.is_open()) {
+    while(getline(info, line)) {
+      auto posDelim = line.find(":");
+      std::string name = line.substr(0, posDelim);
+      long value = std::stol(line.substr(posDelim + 1));
+
+      if(name.compare("MemTotal") == 0) {
+        memtotal = value;
+        count++;
+      } else if(name.compare("MemAvailable") == 0) {
+        memavail = value;
+        count++;
+      } else if(name.compare("MemFree") == 0) {
+        memfree = value;
+        count++;
+      } else if(name.compare("Buffers") == 0) {
+        membuffer = value;
+        count++;
+      } else if(name.compare("Cached") == 0) {
+        memcache = value;
+        count++;
+      }
+      if (count >= 5 || (count >= 4 && memavail >= -1)) {
+        info.close();
+      }
     }
   } else {
+    throw std::runtime_error("Can't open /proc/meminfo");
+  }
   memtotal_ = memtotal;
+  if(memavail >= 0) {
+    memfree_ = memavail;
+  } else {
     memfree_ = memfree + (membuffer + memcache);
   }
-  fclose(info);
 }