我需要的是能够将.rar文件中的文件提取到流中。我正在创建一个测试用例,以了解如何使用unrar source。我一直在寻找和修补一段时间,但我无法弄清楚如何使用该库。我很惊讶我甚至找不到文档或教程,考虑到常见的.rar档案。
我自己取得了一些进展,但并不总是有效。正确提取某些文件。其他文件由于某种原因混乱(但不是完全“垃圾”二进制数据)。到目前为止,我所知道的通常是(但并非总是如此):
不工作的文件有fileInfo.Method = 48
。它们似乎是压缩率为100%的文件 - 即没有压缩
工作文件包含fileInfo.Method = 49
,50
,51
,52
或53
,它们对应于压缩速度,最快,快速,正常,良好,最佳
但我不知道为什么会这样。仍无法找到文档或工作示例。
以下是我到目前为止的测试用例源以及example rar archive,当使用此程序提取时,该文件具有工作文件和非工作文件。
/* put in the same directory as the unrar source files
* compiling with:
* make clean
* make lib
* g++ rartest.cpp -o rartest libunrar.so -lboost_filesystem
*/
#include <cstring>
#include <iostream>
#include <fstream>
#include <boost/filesystem.hpp>
#define _UNIX
#define RARDLL
#include "dll.hpp"
using namespace std;
namespace fs = boost::filesystem;
//char fileName[100] = "testout0.jpg\0";
//
//// doens't work
//int PASCAL ProcessDataProc(unsigned char* buffer, int buffLen) {
// cout << "writing..." << endl;
// ofstream outFile(fileName);
// cout << buffLen << endl;
// cout << outFile.write((const char*)buffer, buffLen) << endl;
// cout << "done writing..." << endl;
// fileName[7]++;
//}
int CALLBACK CallbackProc(unsigned int msg, long myBuffer, long rarBuffer, long bufferLen) {
switch(msg) {
case UCM_CHANGEVOLUME:
break;
case UCM_PROCESSDATA:
memcpy((char*)myBuffer, (char*)rarBuffer, bufferLen);
break;
case UCM_NEEDPASSWORD:
break;
}
return 1;
}
int main(int argc, char* argv[]) {
if (argc != 2)
return 0;
ifstream archiveStream(argv[1]);
if (!archiveStream.is_open())
cout << "fstream couldn't open file\n";
// declare and set parameters
HANDLE rarFile;
RARHeaderDataEx fileInfo;
RAROpenArchiveDataEx archiveInfo;
memset(&archiveInfo, 0, sizeof(archiveInfo));
archiveInfo.CmtBuf = NULL;
//archiveInfo.OpenMode = RAR_OM_LIST;
archiveInfo.OpenMode = RAR_OM_EXTRACT;
archiveInfo.ArcName = argv[1];
// Open file
rarFile = RAROpenArchiveEx(&archiveInfo);
if (archiveInfo.OpenResult != 0) {
RARCloseArchive(rarFile);
cout << "unrar couldn't open" << endl;
exit(1);
}
fileInfo.CmtBuf = NULL;
cout << archiveInfo.Flags << endl;
// loop through archive
int numFiles = 0;
int fileSize;
int RHCode;
int PFCode;
while(true) {
RHCode = RARReadHeaderEx(rarFile, &fileInfo);
if (RHCode != 0) break;
numFiles++;
fs::path path(fileInfo.FileName);
fileSize = fileInfo.UnpSize;
cout << fileInfo.Method << " " << fileInfo.FileName << " (" << fileInfo.UnpSize << ")" << endl;
char fileBuffer[fileInfo.UnpSize];
// not sure what this does
//RARSetProcessDataProc(rarFile, ProcessDataProc);
// works for some files, but not for others
RARSetCallback(rarFile, CallbackProc, (long) &fileBuffer);
PFCode = RARProcessFile(rarFile, RAR_TEST, NULL, NULL);
// properly extracts to a directory... but I need a stream
// and I don't want to write to disk, read it, and delete from disk
//PFCode = RARProcessFile(rarFile, RAR_EXTRACT, ".", fileInfo.FileName);
// just skips
//PFCode = RARProcessFile(rarFile, RAR_SKIP, NULL, NULL);
if (PFCode != 0) {
RARCloseArchive(rarFile);
cout << "error processing this file\n" << endl;
exit(1);
}
ofstream outFile(path.filename().c_str());
outFile.write(fileBuffer, fileSize);
}
if (RHCode != ERAR_END_ARCHIVE)
cout << "error traversing through archive: " << RHCode << endl;
RARCloseArchive(rarFile);
cout << "num files: " << numFiles << endl;
}
更新
我发现一个文件似乎是(声称是?)documentation,但根据文件,我没有做错任何事。我想我可能会被迫使用CRC检查缓冲区并在失败时实施解决方法。
解决方案来源(谢谢,Denis Krjuchkov!):
/* put in the same directory as the unrar source files
* compiling with:
* make clean
* make lib
* g++ rartest.cpp -o rartest libunrar.so -lboost_filesystem
*/
#include <cstring>
#include <iostream>
#include <fstream>
#include <boost/filesystem.hpp>
#include <boost/crc.hpp>
#define _UNIX
#define RARDLL
#include "dll.hpp"
using namespace std;
namespace fs = boost::filesystem;
//char fileName[100] = "testout0.jpg\0";
//
//// doens't work
//int PASCAL ProcessDataProc(unsigned char* buffer, int buffLen) {
// cout << "writing..." << endl;
// ofstream outFile(fileName);
// cout << buffLen << endl;
// cout << outFile.write((const char*)buffer, buffLen) << endl;
// cout << "done writing..." << endl;
// fileName[7]++;
//}
int CALLBACK CallbackProc(unsigned int msg, long myBufferPtr, long rarBuffer, long bytesProcessed) {
switch(msg) {
case UCM_CHANGEVOLUME:
return -1;
break;
case UCM_PROCESSDATA:
memcpy(*(char**)myBufferPtr, (char*)rarBuffer, bytesProcessed);
*(char**)myBufferPtr += bytesProcessed;
return 1;
break;
case UCM_NEEDPASSWORD:
return -1;
break;
}
}
int main(int argc, char* argv[]) {
if (argc != 2)
return 0;
ifstream archiveStream(argv[1]);
if (!archiveStream.is_open())
cout << "fstream couldn't open file\n";
// declare and set parameters
RARHANDLE rarFile; // I renamed this macro in dll.hpp for my own purposes
RARHANDLE rarFile2;
RARHeaderDataEx fileInfo;
RAROpenArchiveDataEx archiveInfo;
memset(&archiveInfo, 0, sizeof(archiveInfo));
archiveInfo.CmtBuf = NULL;
//archiveInfo.OpenMode = RAR_OM_LIST;
archiveInfo.OpenMode = RAR_OM_EXTRACT;
archiveInfo.ArcName = argv[1];
// Open file
rarFile = RAROpenArchiveEx(&archiveInfo);
rarFile2 = RAROpenArchiveEx(&archiveInfo);
if (archiveInfo.OpenResult != 0) {
RARCloseArchive(rarFile);
cout << "unrar couldn't open" << endl;
exit(1);
}
fileInfo.CmtBuf = NULL;
// cout << archiveInfo.Flags << endl;
// loop through archive
int numFiles = 0;
int fileSize;
int RHCode;
int PFCode;
int crcVal;
bool workaroundUsed = false;
char currDir[2] = ".";
char tmpFile[11] = "buffer.tmp";
while(true) {
RHCode = RARReadHeaderEx(rarFile, &fileInfo);
if (RHCode != 0) break;
RARReadHeaderEx(rarFile2, &fileInfo);
numFiles++;
fs::path path(fileInfo.FileName);
fileSize = fileInfo.UnpSize;
crcVal = fileInfo.FileCRC;
cout << dec << fileInfo.Method << " " << fileInfo.FileName << " (" << fileInfo.UnpSize << ")" << endl;
cout << " " << hex << uppercase << crcVal << endl;
char fileBuffer[fileSize];
char* bufferPtr = fileBuffer;
// not sure what this does
//RARSetProcessDataProc(rarFile, ProcessDataProc);
// works for some files, but not for others
RARSetCallback(rarFile, CallbackProc, (long) &bufferPtr);
PFCode = RARProcessFile(rarFile, RAR_TEST, NULL, NULL);
// properly extracts to a directory... but I need a stream
// and I don't want to write to disk, read it, and delete from disk
// PFCode = RARProcessFile(rarFile, RAR_EXTRACT, currDir, fileInfo.FileName);
// just skips
//PFCode = RARProcessFile(rarFile, RAR_SKIP, NULL, NULL);
if (PFCode != 0) {
RARCloseArchive(rarFile);
cout << "error processing this file\n" << endl;
exit(1);
}
// crc check
boost::crc_32_type crc32result;
crc32result.process_bytes(&fileBuffer, fileSize);
cout << " " << hex << uppercase << crc32result.checksum() << endl;
// old workaround - crc check always succeeds now!
if (crcVal == crc32result.checksum()) {
RARProcessFile(rarFile2, RAR_SKIP, NULL, NULL);
}
else {
workaroundUsed = true;
RARProcessFile(rarFile2, RAR_EXTRACT, currDir, tmpFile);
ifstream inFile(tmpFile);
inFile.read(fileBuffer, fileSize);
}
ofstream outFile(path.filename().c_str());
outFile.write(fileBuffer, fileSize);
}
if (workaroundUsed) remove(tmpFile);
if (RHCode != ERAR_END_ARCHIVE)
cout << "error traversing through archive: " << RHCode << endl;
RARCloseArchive(rarFile);
cout << dec << "num files: " << numFiles << endl;
}
答案 0 :(得分:6)
我不熟悉unrar,在快速阅读文档后我认为你假设每个文件只调用一次CallbackProc。但是,我认为unrar可能会多次调用它。它解压缩一些数据然后调用CallbackProc
,然后解压缩下一个数据块并再次调用CallbackProc
,迭代该过程直到处理完所有数据。
您应该记住实际写入缓冲区的字节数,并在相应的偏移处附加新数据。
答案 1 :(得分:3)
我也无法在线找到任何文档,但您可以使用示例:
转到http://www.krugle.com,然后在页面左下角输入关键字RAROpenArchiveEx
。您将看到来自使用unrar库的各种开源项目的头文件和源文件。
这应该让你去。
答案 2 :(得分:0)