opt parser

src/mainclass.cpp

@@ -2,6 +2,8 @@
 #include <iostream>
 #include <libgen.h>
 #include <sysexits.h>
+#include <climits>
+#include <getopt.h>
 
 MainClass::MainClass(int argc, char* argv[])
   : argc_(argc)
@@ -12,13 +14,62 @@ MainClass::MainClass(int argc, char* argv[])
 int MainClass::usage()
 {
   std::cerr << "Usage: " << basename(argv_[0]) <<
-    " [--up 0-7] [--down 0-7] [--sleep ms]" << std::endl;
+    " [--device DEVICE|--device=DEVICE|-e DEVICE]" <<
+    " [--up OUTPUT|--up=OUTPUT|-u OUTPUT]" <<
+    " [--down OUTPUT|--down=OUPUT|-d OUTPUT]" <<
+    " [--sleep MS|--sleep=MS|-s MS]" <<
+    " [--help|-h]" << std::endl;
+  std::cerr << std::endl << "Controls the output pins of a PiFace digital IO."
+    << std::endl << std::endl;
+  std::cerr << "--device \tSwitch to the provided device."
+    << std::endl << "--up \t\tEnable the provided ouput pin."
+    << std::endl << "--down \t\tDisable the provided output pin."
+    << std::endl << "--sleep \tSleep for the provided amount of milliseconds."
+    << std::endl << "--help \t\tDisplay this message."
+    << std::endl << std::endl;
+  std::cerr << "OUTPUT \t: The output pin to enable/disable. 0 <= OUTPUT <= 7."
+    << std::endl << "MS \t: The number of milliseconds to sleep. 0 <= MS <= "
+    << UINT_MAX << "."
+    << std::endl << "DEVICE \t: The device number. Default is 0. "
+    "0 <= DEVICE <= 4" << std::endl;
   return EX_USAGE;
 }
 
+bool MainClass::build_actions_()
+{
+  option opts[] = {
+    {"device", 1, 0, 'e'},
+    {"up", 1, 0, 'u'},
+    {"down", 1, 0, 'd'},
+    {"sleep", 1, 0, 's'},
+    {"help", 0, 0, 'h'},
+    {0, 0, 0, 0}
+  };
+  int opt;
+  extern int optind;
+  while ((opt = getopt_long(argc_, argv_, "e:u:d:s:h", opts, 0)) != -1)
+  {
+    if (opt == 'e')
+    {
+    }
+    else if (opt == 'u')
+    {
+    }
+    else if (opt == 'd')
+    {
+    }
+    else if (opt == 's')
+    {
+    }
+    else
+      return false;
+  }
+  return optind == argc_;
+}
+
 int MainClass::execute()
 {
-  if (argc_ <= 2)
+  if (argc_ <= 2 || !build_actions_())
     return usage();
   return 0;
 }

src/mainclass.hh

@@ -9,6 +9,7 @@ class MainClass
     int execute();
 
   private:
+    bool build_actions_();
     int argc_;
     char** argv_;
 };