Add support for colors.

Colors are added for terminals that have 256 color support when the
--colors flag is enabled.  The background colors are varied with different color
maps derived from their matplotlib versions.  The foreground color is a
contrasting black or white.

CMakeLists.txt

@@ -11,6 +11,8 @@ if(NOT CMAKE_BUILD_TYPE)
       FORCE)
 endif(NOT CMAKE_BUILD_TYPE)
 
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+
 add_executable(tmux-mem-cpu-load tmux-mem-cpu-load.cpp)
 install(TARGETS tmux-mem-cpu-load
   RUNTIME

generate-luts.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+
+"""Create the color code lookup table header."""
+
+import matplotlib.cm
+
+def write_table(fp, colormap_name, stat_name, first_half_foreground, second_half_foreground):
+    fp.write('static const char ')
+    fp.write(stat_name)
+    fp.write('_lut[][32] = {\n')
+    colormap = matplotlib.cm.get_cmap(colormap_name)
+    for ii in range(101):
+        fp.write('"#[fg=')
+        if ii < 50:
+            fp.write(first_half_foreground)
+        else:
+            fp.write(second_half_foreground)
+        fp.write(',bg=colour')
+        rgba = colormap(ii * 0.01)
+        red = int(round(rgba[0] * 5))
+        green = int(round(rgba[1] * 5))
+        blue = int(round(rgba[2] * 5))
+        color = 16 + 36*red + 6*green + blue;
+        fp.write(str(color))
+        fp.write(']"')
+        if ii != 100:
+            fp.write(',')
+        fp.write('\n')
+    fp.write('}; // end ')
+    fp.write(stat_name)
+    fp.write('_lut\n\n')
+
+with open('luts.h', 'w') as fp:
+    fp.write('#ifndef _luts_h\n')
+    fp.write('#define _luts_h\n\n')
+
+    # hot colormap with white fg for the first half
+    # and black fg for the second half
+    write_table(fp, 'hot', 'cpu_percentage', 'white', 'black')
+    write_table(fp, 'gist_earth', 'mem', 'white', 'black')
+    write_table(fp, 'bone', 'load', 'white', 'black')
+
+    fp.write('#endif\n')

luts.h

@@ -0,0 +1,316 @@
+#ifndef _luts_h
+#define _luts_h
+
+static const char cpu_percentage_lut[][32] = {
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour52]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour88]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour124]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour160]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour196]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour202]",
+"#[fg=white,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour208]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour214]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour220]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour226]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour227]",
+"#[fg=black,bg=colour228]",
+"#[fg=black,bg=colour228]",
+"#[fg=black,bg=colour228]",
+"#[fg=black,bg=colour228]",
+"#[fg=black,bg=colour228]",
+"#[fg=black,bg=colour229]",
+"#[fg=black,bg=colour229]",
+"#[fg=black,bg=colour229]",
+"#[fg=black,bg=colour229]",
+"#[fg=black,bg=colour229]",
+"#[fg=black,bg=colour230]",
+"#[fg=black,bg=colour230]",
+"#[fg=black,bg=colour230]",
+"#[fg=black,bg=colour230]",
+"#[fg=black,bg=colour230]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]"
+}; // end cpu_percentage_lut
+
+static const char mem_lut[][32] = {
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour17]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour18]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour24]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour66]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour72]",
+"#[fg=white,bg=colour71]",
+"#[fg=white,bg=colour71]",
+"#[fg=white,bg=colour71]",
+"#[fg=white,bg=colour107]",
+"#[fg=white,bg=colour107]",
+"#[fg=black,bg=colour107]",
+"#[fg=black,bg=colour107]",
+"#[fg=black,bg=colour108]",
+"#[fg=black,bg=colour108]",
+"#[fg=black,bg=colour108]",
+"#[fg=black,bg=colour108]",
+"#[fg=black,bg=colour108]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour144]",
+"#[fg=black,bg=colour150]",
+"#[fg=black,bg=colour150]",
+"#[fg=black,bg=colour186]",
+"#[fg=black,bg=colour186]",
+"#[fg=black,bg=colour186]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour180]",
+"#[fg=black,bg=colour181]",
+"#[fg=black,bg=colour181]",
+"#[fg=black,bg=colour181]",
+"#[fg=black,bg=colour181]",
+"#[fg=black,bg=colour187]",
+"#[fg=black,bg=colour187]",
+"#[fg=black,bg=colour187]",
+"#[fg=black,bg=colour187]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour224]",
+"#[fg=black,bg=colour224]",
+"#[fg=black,bg=colour224]",
+"#[fg=black,bg=colour224]",
+"#[fg=black,bg=colour224]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]"
+}; // end mem_lut
+
+static const char load_lut[][32] = {
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour16]",
+"#[fg=white,bg=colour17]",
+"#[fg=white,bg=colour17]",
+"#[fg=white,bg=colour17]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour59]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour60]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour102]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=white,bg=colour103]",
+"#[fg=black,bg=colour103]",
+"#[fg=black,bg=colour103]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour109]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour145]",
+"#[fg=black,bg=colour146]",
+"#[fg=black,bg=colour146]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour152]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour188]",
+"#[fg=black,bg=colour195]",
+"#[fg=black,bg=colour195]",
+"#[fg=black,bg=colour195]",
+"#[fg=black,bg=colour195]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]",
+"#[fg=black,bg=colour231]"
+}; // end load_lut
+
+#endif

tmux-mem-cpu-load.cpp

@@ -22,6 +22,8 @@
 
 #include <unistd.h> // sleep
 
+#include "luts.h"
+
 float cpu_percentage( unsigned int cpu_usage_delay )
 {
   std::string stat_line;
@@ -81,7 +83,9 @@ float cpu_percentage( unsigned int cpu_usage_delay )
   return static_cast<float>(diff_user + diff_system + diff_nice)/static_cast<float>(diff_user + diff_system + diff_nice + diff_idle)*100.0;
 }
 
-std::string cpu_string( unsigned int cpu_usage_delay, unsigned int graph_lines )
+std::string cpu_string( unsigned int cpu_usage_delay,
+  unsigned int graph_lines,
+  bool use_colors = false )
 {
   std::string meter( graph_lines + 2, ' ' );
   meter[0] = '[';
@@ -95,21 +99,29 @@ std::string cpu_string( unsigned int cpu_usage_delay, unsigned int graph_lines )
   percentage = cpu_percentage( cpu_usage_delay );
   float meter_step = 99.9 / graph_lines;
   meter_count = 1;
-  while(meter_count*meter_step < percentage)
+  while( meter_count*meter_step < percentage )
     {
     meter[meter_count] = '|';
     meter_count++;
     }
 
+  if( use_colors )
+    {
+    oss << cpu_percentage_lut[static_cast<unsigned int>( percentage )];
+    }
   oss << meter;
   oss.width( 5 );
   oss << percentage;
   oss << "%";
+  if( use_colors )
+    {
+    oss << "#[fg=default,bg=default]";
+    }
 
   return oss.str();
 }
 
-std::string mem_string()
+std::string mem_string( bool use_colors = false )
 {
   unsigned int total_mem;
   unsigned int used_mem;
@@ -142,17 +154,58 @@ std::string mem_string()
     }
   meminfo_file.close();
 
+  if( use_colors )
+    {
+    oss << mem_lut[(100 * used_mem) / total_mem];
+    }
   oss << used_mem / 1024 << '/' << total_mem / 1024 << "MB";
+  if( use_colors )
+    {
+    oss << "#[fg=default,bg=default]";
+    }
 
   return oss.str();
 }
 
-std::string load_string()
+std::string load_string( bool use_colors = false )
 {
   std::ifstream loadavg_file( "/proc/loadavg" );
   std::string load_line;
   std::getline( loadavg_file, load_line );
   loadavg_file.close();
+  if( use_colors )
+    {
+    std::ostringstream oss;
+    std::ifstream stat_file( "/proc/stat" );
+    std::string stat_line;
+    std::getline( stat_file, stat_line );
+    unsigned int number_of_cpus = 0;
+    std::getline( stat_file, stat_line );
+    do
+      {
+      ++number_of_cpus;
+      std::getline( stat_file, stat_line );
+      }
+    while( stat_line.compare( 0, 3, "cpu" ) == 0 && stat_file.good() );
+    stat_file.close();
+
+    std::istringstream iss( load_line.substr( 0, 4 ) );
+    float recent_load;
+    iss >> recent_load;
+    // colors range from zero to twice the number of cpu's for the most recent
+    // load metric
+    unsigned int load_percent = static_cast< unsigned int >( recent_load / number_of_cpus * 0.5f * 100.0f );
+    if( load_percent > 100 )
+      {
+      load_percent = 100;
+      }
+
+    oss << load_lut[load_percent];
+    oss << load_line.substr( 0, 14 );
+    oss << "#[fg=default,bg=default]";
+
+    return oss.str();
+    }
 
   return load_line.substr( 0, 14 );
 }
@@ -197,8 +250,7 @@ int main(int argc, char** argv)
     return 1;
     }
 
-  std::cout << use_colors << " " << cpu_usage_delay << " " << graph_lines << std::endl;
+  std::cout << mem_string( use_colors ) << ' ' << cpu_string( cpu_usage_delay, graph_lines, use_colors ) << ' ' << load_string( use_colors );
-  std::cout << mem_string() << ' ' << cpu_string( cpu_usage_delay, graph_lines ) << ' ' << load_string();
 
   return 0;
 }