extracting file inside of directory with miniz - c++

Question

Is there someone that can explain me how i can get files from directories inside a zipfile.
I use c++ and miniz(code.google.com/p/miniz/). thank you in advance.
here my code i have that i use right now:
size_t uncomp_size;
mz_bool status;
mz_zip_archive zip_archive;
memset(&zip_archive, 0, sizeof(zip_archive));
status = mz_zip_reader_init_file(&zip_archive, "data.zip", 0);
if (!status){
puts("failed to open zip file\n");
return 0;
}
try{
void* p = NULL;
std::string file_to_extract = "data//test.txt";
int file_index = mz_zip_reader_locate_file(&zip_archive, file_to_extract.c_str(), NULL, MZ_ZIP_FLAG_IGNORE_PATH);
if (file_index < 0)
{
mz_bool is_dir = mz_zip_reader_is_file_a_directory(&zip_archive,file_index);
if(is_dir){
throw std::exception("file_index = folder");
}else{
throw std::exception("cannot find file in zip(0)");
}
}
p = mz_zip_reader_extract_to_heap(&zip_archive, file_index, &uncomp_size, NULL);
if(!p){
throw std::exception("cannot find file in zip(1)");
}
std::fstream fp1("test.txt",ios::binary|ios::out);
fp1.write(reinterpret_cast<char*>(p),uncomp_size);
fp1.close();
delete p;
}catch(std::exception ex){
cout << ex.what() << endl;
}
mz_zip_reader_end(&zip_archive);

Answer 1

This code is working for me using miniz from here.
string str_zip; // The zip archive in string form.
string str_unzip; // The uncompressed contents of the first file in the zip archive.
// Read in or assign zip contents to the string.
// In my case I receive the zip file via a web service.
// The processing all takes place in memory.
// But you can easily read a file's contents into the zipfile string, as well.
typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned int uint;
mz_zip_archive zip_archive;
mz_bool status;
// Now try to open the archive.
memset(&zip_archive, 0, sizeof(zip_archive));
// You can provide the zip data in memory as I did...
status = mz_zip_reader_init_mem(&zip_archive, str_zip.c_str(), str_zip.size(), 0);
// Or you can just give a filename...
// status = mz_zip_reader_init_file(&zip_archive, "myfile.zip", 0);
if (!status)
{
cout << "zip file appears invalid..." << endl;
return;
}
// Get the first file in the archive.
if (mz_zip_reader_get_num_files(&zip_archive) != 1)
{
cout << "zip file does not contain our 1 file..." << endl;
return;
}
mz_zip_archive_file_stat file_stat;
if (!mz_zip_reader_file_stat(&zip_archive, 0, &file_stat))
{
cout << "zip file read error..." << endl;
mz_zip_reader_end(&zip_archive);
return;
}
// Unzip the file to heap.
size_t uncompressed_size = file_stat.m_uncomp_size;
void* p = mz_zip_reader_extract_file_to_heap(&zip_archive, file_stat.m_filename, &uncompressed_size, 0);
if (!p)
{
cout << "mz_zip_reader_extract_file_to_heap() failed..." << endl;
mz_zip_reader_end(&zip_archive);
return;
}
str_unzip.assign((const char*)p,uncompressed_size);
// Close the archive, freeing any resources it was using
mz_free(p);
mz_zip_reader_end(&zip_archive);

Answer 2

I came up with a solution for this.
Lets we have;
In your C directory:
+-- ZipFile /
+-- folder1 /
+-- file1
+-- folder2 /
+--file2.1
+--file2.2
+--file2.3
bool decompress_folders_inside_zip()
{
const std::string archive_name = "ZipFile.zip";
const std::string decompress_path = "C:\\";
mz_zip_archive archive {};
boost::filesystem::path dec_path { decompress_path + archive_name };
if (!mz_zip_reader_init_file(&archive, dec_path.string().c_str(), 0))
{
return false;
}
const int file_cnt = (int)mz_zip_reader_get_num_files(&archive);
if (0 == file_cnt)
{
return false;
}
mz_zip_archive_file_stat file_stat;
if (!mz_zip_reader_file_stat(&archive, 0, &file_stat))
{
mz_zip_reader_end(&archive);
return false;
}
for (int i = 0; i < file_cnt; ++i)
{
mz_zip_reader_file_stat(&archive, i, &file_stat);
if (mz_zip_reader_is_file_a_directory(&archive, i))
{
boost::filesystem::path dir(decompress_path + file_stat.m_filename);
boost::filesystem::create_directories(dir.parent_path());
continue;
}
boost::filesystem::path file_out(decompress_path + file_stat.m_filename);
boost::filesystem::path out_file(file_out.parent_path().generic_string() + "/" + file_out.filename().string());
if (!mz_zip_reader_extract_to_file(&archive, i, out_file.string().c_str(), 0))
{
mz_zip_reader_end(&archive);
return false;
}
}
if (!mz_zip_reader_end(&archive))
{
return false;
}
std::cout << "Completed" << std::endl;
return true;
}