Okay so i am trying to make it so i can unzip files using c++ and found a library called zlib i built all .sln file in the folder contrib/vstudio they all compiled succesfully but when i try to get this example to work
/*
unzips testfile.txt from C:\temp\test.zip
and puts it in a string
*/
#define ZLIB_WINAPI // dont know if i need this or not
#include <cstdio>
#include <string>
#include <iostream>
#include "unzip.h" // MiniZip library
#define WRITEBUFFERSIZE (5242880) // 5Mb buffer
using namespace std;
string readZipFile(string zipFile, string fileInZip) {
int err = UNZ_OK; // error status
uInt size_buf = WRITEBUFFERSIZE; // byte size of buffer to store raw csv data
void* buf; // the buffer
string sout; // output strings
char filename_inzip[256]; // for unzGetCurrentFileInfo
unz_file_info file_info; // for unzGetCurrentFileInfo
unzFile uf = unzOpen(zipFile.c_str()); // open zipfile stream
if (uf==NULL) {
cerr << "Cannot open " << zipFile << endl;
return sout;
} // file is open
if ( unzLocateFile(uf,fileInZip.c_str(),1) ) { // try to locate file inside zip
// second argument of unzLocateFile: 1 = case sensitive, 0 = case-insensitive
cerr << "File " << fileInZip << " not found in " << zipFile << endl;
return sout;
} // file inside zip found
if (unzGetCurrentFileInfo(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0)) {
cerr << "Error " << err << " with zipfile " << zipFile << " in unzGetCurrentFileInfo." << endl;
return sout;
} // obtained the necessary details about file inside zip
buf = (void*)malloc(size_buf); // setup buffer
if (buf==NULL) {
cerr << "Error allocating memory for read buffer" << endl;
return sout;
} // buffer ready
err = unzOpenCurrentFilePassword(uf,NULL); // Open the file inside the zip (password = NULL)
if (err!=UNZ_OK) {
cerr << "Error " << err << " with zipfile " << zipFile << " in unzOpenCurrentFilePassword." << endl;
return sout;
} // file inside the zip is open
// Copy contents of the file inside the zip to the buffer
cout << "Extracting: " << filename_inzip << " from " << zipFile << endl;
do {
err = unzReadCurrentFile(uf,buf,size_buf);
if (err<0) {
cerr << "Error " << err << " with zipfile " << zipFile << " in unzReadCurrentFile" << endl;
sout = ""; // empty output string
break;
}
// copy the buffer to a string
if (err>0) for (int i = 0; i < (int) err; i++) sout.push_back( *(((char*)buf)+i) );
} while (err>0);
err = unzCloseCurrentFile (uf); // close the zipfile
if (err!=UNZ_OK) {
cerr << "Error " << err << " with zipfile " << zipFile << " in unzCloseCurrentFile" << endl;
sout = ""; // empty output string
}
free(buf); // free up buffer memory
return sout;
}
int main(int argc, char *argv[]) {
string string_buffer = readZipFile("C:/temp/test.zip", "testfile.txt");
cout << string_buffer << endl;
return 0;
}
i get these linker errors
1>main.obj : error LNK2019: unresolved external symbol _unzCloseCurrentFile@4 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
1>main.obj : error LNK2019: unresolved external symbol _unzReadCurrentFile@12 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
1>main.obj : error LNK2019: unresolved external symbol _unzOpenCurrentFilePassword@8 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
1>main.obj : error LNK2019: unresolved external symbol _unzGetCurrentFileInfo@32 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
1>main.obj : error LNK2019: unresolved external symbol _unzLocateFile@12 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
1>main.obj : error LNK2019: unresolved external symbol _unzOpen@4 referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl readZipFile(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >)" (?readZipFile@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@0@Z)
I have no idea what they mean.
I have looked in the file named unzip.h for the commands i can use but i dont know how to use them if i dont have a good example of them working and sadly the example that comes with it named miniunz.c is messy and hard to read at least for me. If any of you know a good example i guess that would work too.
if you need more info please ask
