start with the scripts

screen-cpu-usage.cpp

@@ -0,0 +1,144 @@
+/** 
+ * @file cpuusage.cpp
+ * @brief print out the percent cpu usage at a given interval
+ * @author Matthew McCormick (thewtex)
+ * @version 
+ * @date 2009-08-12
+ */
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+using namespace std;
+
+#include <unistd.h> // sleep
+
+// in seconds
+const static unsigned int INTERVAL=1;
+
+class CPUPercentage
+{
+public:
+  CPUPercentage();
+  ~CPUPercentage();
+
+  const float& get_percentage();
+
+private:
+  ifstream m_stat_file;
+  unsigned long long m_current_user;
+  unsigned long long m_current_system;
+  unsigned long long m_current_nice;
+  unsigned long long m_current_idle;
+  unsigned long long m_next_user;
+  unsigned long long m_next_system;
+  unsigned long long m_next_nice;
+  unsigned long long m_next_idle;
+  unsigned long long m_diff_user;
+  unsigned long long m_diff_system;
+  unsigned long long m_diff_nice;
+  unsigned long long m_diff_idle;
+
+  string m_stat_line;
+  size_t m_line_start_pos;
+  size_t m_line_end_pos;
+  istringstream m_iss;
+
+  float m_percentage;
+};
+
+CPUPercentage::CPUPercentage():
+  m_current_user(0),
+  m_current_system(0),
+  m_current_nice(0),
+  m_current_idle(0),
+  m_next_user(0),
+  m_next_system(0),
+  m_next_nice(0),
+  m_next_idle(0),
+  m_diff_user(0),
+  m_diff_system(0),
+  m_diff_nice(0),
+  m_diff_idle(0)
+{
+  m_stat_file.exceptions(ifstream::eofbit|ifstream::failbit|ifstream::badbit);
+}
+
+CPUPercentage::~CPUPercentage()
+{
+  if(m_stat_file.is_open())
+    m_stat_file.close();
+}
+
+const float& CPUPercentage::get_percentage()
+{
+  m_stat_file.open("/proc/stat");
+  getline(m_stat_file, m_stat_line);
+  m_stat_file.close();
+
+  // skip "cpu"
+  m_line_start_pos = m_stat_line.find_first_not_of(" ", 3);
+  m_line_end_pos = m_stat_line.find_first_of(' ', m_line_start_pos);
+  m_line_end_pos = m_stat_line.find_first_of(' ', m_line_end_pos + 1);
+  m_line_end_pos = m_stat_line.find_first_of(' ', m_line_end_pos + 1);
+  m_line_end_pos = m_stat_line.find_first_of(' ', m_line_end_pos + 1);
+  m_iss.str(m_stat_line.substr(m_line_start_pos, m_line_end_pos - m_line_start_pos));
+  m_iss >> m_next_user >> m_next_nice >> m_next_system >> m_next_idle;
+  m_iss.clear();
+
+  m_diff_user   = m_next_user - m_current_user;
+  m_diff_system = m_next_system - m_current_system;
+  m_diff_nice   = m_next_nice - m_current_nice;
+  m_diff_idle   = m_next_idle - m_current_idle;
+  m_percentage = static_cast<float>(m_diff_user + m_diff_system + m_diff_nice)/static_cast<float>(m_diff_user + m_diff_system + m_diff_nice + m_diff_idle)*100.0;
+
+  m_current_user = m_next_user;
+  m_current_system = m_next_system;
+  m_current_nice = m_next_nice;
+  m_current_idle = m_next_idle;
+
+  return m_percentage;
+}
+
+
+int main(int argc, char** argv)
+{
+  string meter = "[          ]";
+  int meter_count = 0;
+  float percentage = 0.0;
+  CPUPercentage cpu_per;
+  cout.precision(1);
+  cout.setf(ios::fixed | ios::right);
+  cout.width(5);
+  try
+  {
+  while(true)
+    {
+    percentage = cpu_per.get_percentage();
+    
+    meter_count = 1;
+    while(meter_count*9.99 < percentage)
+      {
+      meter[meter_count] = '|';
+      meter_count++;
+      }
+    while(meter_count <= 10)
+      {
+      meter[meter_count] = ' ';
+      meter_count++;
+      }
+    cout << meter << ' ';
+    cout.width(5);
+    cout << percentage << endl; 
+    sleep(1);
+    }
+  }
+  catch(const exception &e)
+  {
+    cerr << "Error: " << e.what() << endl;
+    return 1;
+  }
+  
+  return 0;
+}
+

screen-mem-usage

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+total_mem=$(free -m | awk '$1 == "Mem:" { print $2 }')
+
+while(true); do
+  current_mem=$(free -m | awk '$1 == "-/+" { print $3 }')
+  echo "${current_mem}MB/${total_mem}MB"
+  sleep 3
+done