Loading XSL from memory.

load_xml.cpp

/**
  BSD 3-Clause License

  Copyright (c) 2019, TheWover, Odzhan. All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this
    list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation
    and/or other materials provided with the distribution.

  * Neither the name of the copyright holder nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <windows.h>
#include <msxml2.h>

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <inttypes.h>
#include <fcntl.h>
#include <io.h>

#pragma comment (lib, "msxml2.lib")
#pragma comment (lib, "ole32.lib")

// read and convert the script into unicode format
// return pointer to the script in memory
PWCHAR read_script(const char *path) {
    int         in, len, i;
    struct stat fs;
    PWCHAR      mem;
    uint8_t     c;
    
    // Script is inaccessibe? exit
    if(stat(path, &fs) != 0) return NULL;

    // Zero file size? exit
    if(fs.st_size == 0) return NULL;

    // Open script for reading
    in = open(path, O_RDONLY);
    if(in == 0) return NULL;
    
    // allocate memory for writing
    mem = (PWCHAR)calloc(1, (fs.st_size + 1) * 2);
    if(mem != NULL) {
      // convert input to unicode
      for(i=0;;i++) {
        len = read(in, &c, 1);
        if(len == 0) break;
        mem[i] = c;
      }
    }
    close(in);
    return mem;
}

void run_xml_script(const char *path) {
    IXMLDOMDocument *pDoc; 
    IXMLDOMNode     *pNode;
    HRESULT         hr;
    PWCHAR          xml_str;
    VARIANT_BOOL    loaded;
    BSTR            res;
    
    xml_str = read_script(path);
    
    if(xml_str == NULL) return;
    
    // 1. Initialize COM
    hr = CoInitialize(NULL);
    if(hr == S_OK) {
      // 2. Instantiate XMLDOMDocument object
      hr = CoCreateInstance(
        &CLSID_DOMDocument30, 
        NULL, CLSCTX_INPROC_SERVER,
        &IID_IXMLDOMDocument, 
        (void**)&pDoc);
        
      if(hr == S_OK) {
        // 3. load XML file
        hr = pDoc->lpVtbl->loadXML(pDoc, xml_str, &loaded);
        if(hr == S_OK) {
          // 4. create node interface
          hr = pDoc->lpVtbl->QueryInterface(
            pDoc, &IID_IXMLDOMNode, (void **)&pNode);
            
          if(hr == S_OK) {
            // 5. execute script
            hr = pDoc->lpVtbl->transformNode(pDoc, pNode, &res);
            pNode->lpVtbl->Release(pNode);
          }
        }
        pDoc->lpVtbl->Release(pDoc);
      }
      CoUninitialize();
    }
    free(xml_str);
}

int main(int argc, char *argv[])
{
    if(argc != 2) {
      printf("usage: load_xml <file.xml>\n");
      return 0;
    }
    run_xml_script(argv[1]);
    return 0;
}