Unable to unzip files to a folder

Question

I am trying to unzip a .zip file, at a specified location. The user inputs the name of the file to be unzipped like "D:\\folder\\sample.zip". I am making use of zip headers and .cpp files from this link https://www.codeproject.com/articles/7530/zip-utils-clean-elegant-simple-c-win

Now below is my code

int main()
{
    char filename[100];
    HZIP hz; DWORD writ;
    printf("Enter filename: \n");
    gets(filename);
    TCHAR *name = (TCHAR *) filename;
    hz = OpenZip(name,0);
    SetUnzipBaseDir(hz,_T("D:\\unzipped\\"));
    ZIPENTRY ze; 
    GetZipItem(hz,-1,&ze); 
    int numitems=ze.index;
    for (int zi=0; zi<numitems; zi++)
    {
        GetZipItem(hz,zi,&ze);
        UnzipItem(hz,zi,ze.name);
    }
    CloseZip(hz);
    printf("Unzipped\n");   
    return 0;
}

I need the filename to be taken as input from the user, for which I had to typecast it by using this statement

TCHAR *name = (TCHAR *) filename;

But this is the statement that is causing problems now. When I debugged the program and added watch to the variable 'name', I saw that after typecasting, it stored some Chinese letters, instead of the path of the zip file

Previously the code worked fine when instead of taking input from user, I hardcoded the path and file name as mentioned below

hz = OpenZip(_T("D:\\folder\\sample.zip"),0);

Any ideas what am I doing wrong?

possibly helpful: http://stackoverflow.com/questions/4826189/convert-char-to-wchar-in-c — A.S.H, Dec 04 '16 at 15:05
would you try this: `wstring filename; std::wcin >> filename; OpenZip(filename.c_str(), 0);` — A.S.H, Dec 04 '16 at 16:41
That's great. It worked like a charm! Can you explain how this works? @A.S.H — user52327, Dec 04 '16 at 17:01
***Any ideas what am I doing wrong?*** `TCHAR *name = (TCHAR *) filename;` This is a bug if char is not the same as TCHAR. Casting silences the compiler but does not fix the problem. — drescherjm, Dec 04 '16 at 17:03

A.S.H · Accepted Answer · 2016-12-04T19:13:10.787

0

The Windows file systems (NTFS, FAT32) encode file names in Unicode (UTF16). That is why the OpenZip API expect a wchar_t* (string of wide characters) as the file name parameter.

The C++ standard provides a wstring class similar to the ANSI string (or C string) that is supposed to contain Unicode characters, and a wcin and wcout streams for input/output in Unicode encoding.

wstring wfilename; 
std::wcin >> wfilename;
OpenZip(wfilename.c_str(), 0); // c_str() retrives the wchar_t* in the buffer, much similarly to the ANSI `string.

EDIT: Since you need to input into a C-style buffer, here is the easiest way to convert a C-style char[] to wstring and wchar_t[]:

char filename[100]; printf("Enter filename: \n");   cin >> filename;

// conversion
std::wstring wFilename(strlen(filename), L' ');
std::copy(filename, filename + wFilename.length(), wFilename.begin());


OpenZip(wFilename.c_str(), 0);

edited Dec 04 '16 at 19:13

answered Dec 04 '16 at 17:35

A.S.H

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Is there any way I could convert my char filename[100] to wstring? Because there is certain limitation that I have to take input in char array :/ – user52327 Dec 04 '16 at 17:37
This is perfect! Also thanks for the explanation, really appreciate it – user52327 Dec 04 '16 at 18:49
@user52327 I am glad it helped :) – A.S.H Dec 04 '16 at 19:07

Unable to unzip files to a folder

1 Answers1