HepMC3 event record library
HepMC3_fileIO_example.cc

Test of file I/OParses HepMC3 file and saves it as a new HepMC3 file. The resulting file should be an exact copy of the input file

// -*- C++ -*-
//
// This file is part of HepMC
// Copyright (C) 2014-2019 The HepMC collaboration (see AUTHORS for details)
//
/**
* @example HepMC3_fileIO_example.cc
* @brief Test of file I/O
*
* Parses HepMC3 file and saves it as a new HepMC3 file.
* The resulting file should be an exact copy of the input file
*
*/
#include "HepMC3/Print.h"
#include <iostream>
using namespace HepMC3;
/** Main program */
int main(int argc, char **argv) {
if( argc<3 ) {
std::cout << "Usage: " << argv[0] << " <HepMC3_input_file> <output_file>" << std::endl;
exit(-1);
}
ReaderAscii input_file (argv[1]);
WriterAscii output_file(argv[2]);
int events_parsed = 0;
while(!input_file.failed()) {
GenEvent evt(Units::GEV,Units::MM);
// Read event from input file
input_file.read_event(evt);
// If reading failed - exit loop
if( input_file.failed() ) break;
// Save event to output file
output_file.write_event(evt);
if(events_parsed==0) {
std::cout << " First event: " << std::endl;
std::cout << " Testing attribute reading for the first event: " << std::endl;
std::shared_ptr<GenCrossSection> cs = evt.attribute<GenCrossSection>("GenCrossSection");
std::shared_ptr<GenHeavyIon> hi = evt.attribute<GenHeavyIon>("GenHeavyIon");
std::shared_ptr<GenPdfInfo> pi = evt.attribute<GenPdfInfo>("GenPdfInfo");
if(cs) {
std::cout << " Has GenCrossSection: ";
}
else std::cout << " No GenCrossSection " << std::endl;
if(pi) {
std::cout << " Has GenPdfInfo: ";
}
else std::cout << " No GenPdfInfo " << std::endl;
if(hi) {
std::cout << " Has GenHeavyIon: ";
}
else std::cout << " No GenHeavyIon " << std::endl;
}
++events_parsed;
if( events_parsed%100 == 0 ) std::cout<<"Events parsed: "<<events_parsed<<std::endl;
}
input_file.close();
output_file.close();
return 0;
}