Invoking Lua script using Eval with hiredis

Lua hiredis

/*----------------------
  EVAL
  ------------------------*/

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <hiredis/hiredis.h>
#include <boost/thread/thread.hpp>

using namespace std;

struct timeval _timeout ;
redisContext *_redisContext;
const long long SEC_TO_USEC = 1000000 ;

void connect(const std::string &ip,
    int port,
    int timeoutInUsec )
{
  _timeout.tv_sec = timeoutInUsec / SEC_TO_USEC ;
  _timeout.tv_usec = timeoutInUsec % SEC_TO_USEC ;

  _redisContext = redisConnectWithTimeout(ip.c_str(), port, _timeout);
  if (_redisContext->err)
  {
    std::cout << "Cannot connect to redis server. "
      << " Error : " << _redisContext->errstr
      << std::endl ;
    exit(1);
  }
}

string scriptSingleCommand = "local link_id = redis.call(\"INCR\", KEYS[1]) "
"return link_id ";

string scriptMultipleCommands = 
"local link_id = redis.call(\"INCR\", KEYS[1])          "
"redis.call(\"HSET\", KEYS[2], link_id, ARGV[1])        "
"local data = redis.call(\"HGETALL\",KEYS[2])           "
"return data                                            ";

void eval()
{
  redisReply *reply = 
    ( redisReply * ) redisCommand( _redisContext,
        "eval %s 1 %s", "return {KEYS[1]}", "key1") ;

  if (reply->type == REDIS_REPLY_ARRAY) {
    for (int j = 0; j < reply->elements; j++) {
      cout<< j <<","<<reply->element[j]->str<<endl;
    }
  }
  cout<<"EVAL: "<< reply->str<<endl;
  freeReplyObject(reply);
}

void evalSingleCommand()
{
  string command;
  command.append( scriptSingleCommand );
  redisReply *reply = 
    ( redisReply * ) redisCommand( _redisContext,
        "EVAL %s %d %s ",command.c_str(),1,"a");

  if (reply->type == REDIS_REPLY_ARRAY) {
    for (int j = 0; j < reply->elements; j++) {
      cout<< j <<","<<reply->element[j]->str<<endl;
    }
  }
  cout<<endl<<"EVAL: "<< reply->str<<endl;
  freeReplyObject(reply);
}

void evalMultipleCommands(char** argv)
{
  string command;
  command.append( scriptMultipleCommands );
  redisReply *reply = 
    ( redisReply * ) redisCommand( _redisContext,
        "EVAL %s %d %s %s %s",command.c_str(),2,argv[1],argv[2],argv[3]);

  cout<<"Redis reply type "<<reply->type<<endl;

  if (reply->type == REDIS_REPLY_ARRAY)
  {
    cout<<"Redis reply size "<<reply->elements<<endl;
    for (int j = 0; j < reply->elements; j++)
    {
      if((j+1) < reply->elements)
      {
        cout<<(reply->element[j]->str)<<","<<(reply->element[j+1]->str)<<endl;
        ++j;
      }
    }
  }
  else if (reply->type == REDIS_REPLY_INTEGER) {
    cout<<"Key value "<<reply->integer<<endl;
  }
  else
    cout<<endl<<"EVAL: "<< reply->str<<endl;

  freeReplyObject(reply);
}

int main(int argc,char** argv)
{
  connect("10.0.0.30",6379,1500000);
  //  eval();
  //  evalSingleCommand();
  evalMultipleCommands(argv);

  return 0;
}