dlib C++ Library - file_to_code_ex.cpp

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
 This is an example illustrating the use of the compress_stream and
 base64 components from the dlib C++ Library.
 It reads in a file from the disk and compresses it in an in memory buffer and
 then converts that buffer into base64 text. The final step is to output to
 the screen some C++ code that contains this base64 encoded text and can decompress
 it back into its original form.
*/
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <cstdlib>
#include <dlib/compress_stream.h>
#include <dlib/base64.h>
using namespace std;
using namespace dlib;
int main(int argc, char** argv)
{
 if (argc != 2)
 {
 cout << "You must give a file name as the argument to this program.\n" << endl;
 cout << "This program reads in a file from the disk and compresses\n"
 << "it in an in memory buffer and then converts that buffer \n"
 << "into base64 text. The final step is to output to the screen\n"
 << "some C++ code that contains this base64 encoded text and can\n"
 << "decompress it back into its original form.\n" << endl;
 return EXIT_FAILURE;
 }
 // open the file the user specified on the command line
 ifstream fin(argv[1], ios::binary);
 if (!fin) {
 cout << "can't open file " << argv[1] << endl;
 return EXIT_FAILURE;
 }
 ostringstream sout;
 istringstream sin;
 // this is the object we will use to do the base64 encoding
 base64 base64_coder;
 // this is the object we will use to do the data compression
 compress_stream::kernel_1ea compressor;
 // compress the contents of the file and store the results in the string stream sout
 compressor.compress(fin,sout);
 sin.str(sout.str());
 sout.clear();
 sout.str("");
 // now base64 encode the compressed data
 base64_coder.encode(sin,sout);
 sin.clear();
 sin.str(sout.str());
 sout.str("");
 // the following is a little funny looking but all it does is output some C++ code
 // that contains the compressed/base64 data and the C++ code that can decode it back
 // into its original form.
 sout << "#include <sstream>\n";
 sout << "#include <dlib/compress_stream.h>\n";
 sout << "#include <dlib/base64.h>\n";
 sout << "\n";
 sout << "// This function returns the contents of the file '" << argv[1] << "'\n";
 sout << "const std::string get_decoded_string()\n";
 sout << "{\n";
 sout << " dlib::base64 base64_coder;\n";
 sout << " dlib::compress_stream::kernel_1ea compressor;\n";
 sout << " std::ostringstream sout;\n";
 sout << " std::istringstream sin;\n\n";
 sout << " // The base64 encoded data from the file '" << argv[1] << "' we want to decode and return.\n";
 string temp;
 getline(sin,temp);
 while (sin && temp.size() > 0)
 {
 sout << " sout << \"" << temp << "\";\n";
 getline(sin,temp);
 }
 sout << "\n";
 sout << " // Put the data into the istream sin\n";
 sout << " sin.str(sout.str());\n";
 sout << " sout.str(\"\");\n\n";
 sout << " // Decode the base64 text into its compressed binary form\n";
 sout << " base64_coder.decode(sin,sout);\n";
 sout << " sin.clear();\n";
 sout << " sin.str(sout.str());\n";
 sout << " sout.str(\"\");\n\n";
 sout << " // Decompress the data into its original form\n";
 sout << " compressor.decompress(sin,sout);\n\n";
 sout << " // Return the decoded and decompressed data\n";
 sout << " return sout.str();\n";
 sout << "}\n";
 // finally output our encoded data and its C++ code to the screen
 cout << sout.str() << endl;
}