cli.cpp

/**
 * Copyright 2013 Blake Matheny
 */
extern "C" {
  #include <getopt.h>
}

#include <cstdlib>
#include <string>
#include "common.h"
#include "cli.h"

namespace mckeys {

static const struct option longopts[] = {
  {"discard", required_argument, 0, 'd'},
  {"interface", required_argument, 0, 'i'},
  {"port", required_argument, 0, 'p'},
  {"refresh", required_argument, 0, 'r'},
  {"help", no_argument, 0, 'h'},
  {"verbose", no_argument, 0, 'v'},
  {"version", no_argument, 0, 'V'},
  {"logfile", required_argument, 0, 'l'},
  {"report", required_argument, 0, 'R'}
};
static const char * argp = "d:i:l:p:r:R:hvV";

using std::cout;            using std::endl;
using std::string;          using std::ostringstream;

string Cli::help(const char * progname) {
  ostringstream txt;
  string pname = progname;
  string tab = "    ";
  txt << "Usage: " << pname << " -i NIC [options]" << endl;
  txt << mkHelpDoc(longopts[0],
                   "Discard keys where req/s rate is below THRESH", "THRESH");
  txt << mkHelpDoc(longopts[1],
                   "Network interface to capture traffic on (required)", "NIC");
  txt << mkHelpDoc(
          longopts[2],
          "Network port to capture memcache traffic on (default 11211)",
          "PORT");
  txt << mkHelpDoc(
          longopts[3],
          "Refresh the stats display every INTERVAL ms (default 500)",
          "INTERVAL");
  txt << mkHelpDoc(longopts[7], "Output logs to FILE", "FILE");
  txt << mkHelpDoc(
          longopts[8],
          "Output data in REPORT format (CSV or curses, default curses)",
          "REPORT");
  txt << endl;
  txt << mkHelpDoc(longopts[4], "This help", "");
  txt << mkHelpDoc(longopts[5],
                   "Increase verbosity. May be used multiple times.", "");
  txt << mkHelpDoc(longopts[6], "Show program info and exit.", "");
  return txt.str();
}

/**
 * Parse the command line arguments, updating a config as appropriate.
 */
void Cli::parse(int argc, char ** argv, Config * cfg) {
  int c;
  char * progname = argv[0];
  while (1) {
    int option_index = 0;
    c = getopt_long(argc, argv, argp, longopts, &option_index);
    if (c == -1)
      break;
    switch (c) {
      case 'd':
        cfg->setDiscardThreshold(::atof(optarg));
        break;
      case 'i':
        cfg->setInterface(optarg);
        break;
      case 'l':
        cfg->setLogfile(optarg);
        break;
      case 'p':
        cfg->setPort(::atoi(optarg));
        break;
      case 'r':
        cfg->setRefreshInterval(::atoi(optarg));
        break;
      case 'R':
        cfg->setReportType(optarg);
        break;
      case 'h':
        cout << Cli::help(progname);
        exit(EXIT_SUCCESS);
      case 'v':
        cfg->increaseVerbosity();
        break;
      case 'V':
        cout << "Package: " << PACKAGE_STRING << endl;
        cout << "Author : " << PACKAGE_BUGREPORT << endl;
        cout << "License: Apache 2.0" << endl;
        exit(EXIT_SUCCESS);
      case '?':
        cout << "Unknown flag specified" << endl;
        cout << Cli::help(progname);
        exit(EXIT_FAILURE);
      default:
        cout << "Unknown flag specified" << endl;
        cout << Cli::help(progname);
        exit(EXIT_FAILURE);
    }
  }
}

string Cli::mkHelpLead(const struct option opt, const string &key) {
  ostringstream txt;
  static const char c = 0;
  ssize_t len = 0, alloc = 33;
  char * os = NULL;
  txt << "    -" << static_cast<char>(opt.val) << ", --" << opt.name;
  if (opt.has_arg == 1) {
    txt << "=" << key;
  } else if (opt.has_arg == 2) {
    txt << "[=" << key << "]";
  }
  len = txt.str().length();
  alloc += len;
  os = reinterpret_cast<char*>(malloc(sizeof(c)*alloc));
  snprintf(os, alloc, "%-32s", txt.str().c_str());
  return string(os);
}

string Cli::mkHelpDoc(const struct option opt, const string &desc,
                      const string &key) {
  ostringstream txt;
  string lead = mkHelpLead(opt, key);
  txt << lead << desc << endl;
  return txt.str();
}

}  // namespace mckeys