Unicode C

Unzip One File to a Stream

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Demonstrates how to unzip a particular file contained within a .zip archive to a Chilkat stream. Unicode C

#include <C_CkZipW.h>
#include <C_CkZipEntryW.h>
#include <C_CkStreamW.h>
#include <C_CkTaskW.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkZipW zip;
    HCkZipEntryW entry;
    HCkStreamW streamA;
    HCkStreamW streamB;
    HCkTaskW unzipTask;
    HCkStringBuilderW sb;
    HCkStreamW streamC;
    const wchar_t *s;

    success = FALSE;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    zip = CkZipW_Create();

    // First open a .zip.
    success = CkZipW_OpenZip(zip,L"qa_data/hamlet.zip");
    if (success == FALSE) {
        wprintf(L"%s\n",CkZipW_lastErrorText(zip));
        CkZipW_Dispose(zip);
        return;
    }

    // Find the entry to be unzipped to a stream..
    entry = CkZipEntryW_Create();
    success = CkZipW_EntryMatching(zip,L"*hamlet.xml",entry);
    if (success == FALSE) {
        wprintf(L"%s\n",CkZipW_lastErrorText(zip));
        CkZipW_Dispose(zip);
        CkZipEntryW_Dispose(entry);
        return;
    }

    // There are three ways we can unzip (inflate) to a stream.
    // 
    // 1) Set a sink file on the stream object and call UnzipToStream synchronously.
    //    This unzips to the stream's sink (which is to simply unzip to a file in the filesystem).
    // 
    // 2) Create a stream object and call UnzipToStreamAsync.  This starts the unzip in a background
    //    thread (after Task.Run is called).  Your application can then read the unzipped (inflated) file
    //    directly from the stream.
    // 
    // 3) (not shown in this example) Unzip to a stream object that is the source of something else.
    //    

    // ----------------------------------------------------------------
    // Case 1: Unzip to a file by setting the sink of streamA to a file.
    streamA = CkStreamW_Create();
    CkStreamW_putSinkFile(streamA,L"qa_output/hamletA.xml");

    success = CkZipEntryW_UnzipToStream(entry,streamA);
    if (success != TRUE) {
        wprintf(L"%s\n",CkZipEntryW_lastErrorText(entry));
        CkZipW_Dispose(zip);
        CkZipEntryW_Dispose(entry);
        CkStreamW_Dispose(streamA);
        return;
    }

    // Close the stream to close the output file.
    success = CkStreamW_WriteClose(streamA);

    // ----------------------------------------------------------------
    // Case 2a: Uzip to a stream asynchronously. 
    streamB = CkStreamW_Create();

    unzipTask = CkZipEntryW_UnzipToStreamAsync(entry,streamB);
    if (CkZipEntryW_getLastMethodSuccess(entry) != TRUE) {
        wprintf(L"%s\n",CkZipEntryW_lastErrorText(entry));
        CkZipW_Dispose(zip);
        CkZipEntryW_Dispose(entry);
        CkStreamW_Dispose(streamA);
        CkStreamW_Dispose(streamB);
        return;
    }

    // Start the background unzip thread.
    CkTaskW_Run(unzipTask);

    // Read the stream.  (this is reading the unzipped file data)
    sb = CkStringBuilderW_Create();
    while (CkStreamW_getEndOfStream(streamB) != TRUE) {
        // Each call to ReadSb appends to the contents of sb.
        CkStreamW_ReadSb(streamB,sb);
    }

    CkStringBuilderW_WriteFile(sb,L"qa_output/hamletB.xml",L"utf-8",FALSE);

    CkTaskW_Dispose(unzipTask);
    wprintf(L"Success.\n");

    // ----------------------------------------------------------------
    // Case 2b: Uzip to a stream asynchronously and emit output while reading. 
    streamC = CkStreamW_Create();

    unzipTask = CkZipEntryW_UnzipToStreamAsync(entry,streamC);
    if (CkZipEntryW_getLastMethodSuccess(entry) != TRUE) {
        wprintf(L"%s\n",CkZipEntryW_lastErrorText(entry));
        CkZipW_Dispose(zip);
        CkZipEntryW_Dispose(entry);
        CkStreamW_Dispose(streamA);
        CkStreamW_Dispose(streamB);
        CkStringBuilderW_Dispose(sb);
        CkStreamW_Dispose(streamC);
        return;
    }

    CkTaskW_Run(unzipTask);

    while (CkStreamW_getEndOfStream(streamC) != TRUE) {
        s = CkStreamW_readString(streamC);
        wprintf(L"%s\n",s);
    }

    CkTaskW_Dispose(unzipTask);
    wprintf(L"Success.\n");


    CkZipW_Dispose(zip);
    CkZipEntryW_Dispose(entry);
    CkStreamW_Dispose(streamA);
    CkStreamW_Dispose(streamB);
    CkStringBuilderW_Dispose(sb);
    CkStreamW_Dispose(streamC);

    }