I want to use the libxml2 lib to parse my xml files.
Now, when I have some bad xml file the lib itself is printing large error messages.
below is some sample code
reader = xmlReaderForFile(filename, NULL, 0);
if (reader != NULL) {
ret = xmlTextReaderRead(reader);
while (ret == 1) {
printf("_________________________________\n");
processNode(reader);
ret = xmlTextReaderRead(reader);
printf("_________________________________\n");
}
xmlFreeTextReader(reader);
if (ret != 0) {
fprintf(stderr, "%s : failed to parse\n", filename);
}
}
In above example, if I have bad xml file, I get error like this
my.xml:4: parser error : attributes construct error
include type="text"this is text. this might be excluded in the next occurrence
my.xml:4: parser error : Couldn't find end of Start Tag include
include type="text"this is text. this might be excluded in the next occurrence
my.xml : failed to parse
Instead, I just want to return some error no. and get off with this ugly lib messages.
what do I do ?
The last parameter to xmlReaderForFile(filename, NULL, 0); is a set of option flags. Reading the documentation for these flags, I see there are two options you might want to set: XML_PARSE_NOERROR and XML_PARSE_NOWARNING. Note that I haven't tried any of this, I just Googled libxml2 and xmlReaderForFile.
You will need to or the flags together like this:
reader = xmlReaderForFile(filename, NULL, XML_PARSE_NOERROR | XML_PARSE_NOWARNING);
Related
I've encountered a problem I am trying to figure out for a while now but I am unable to find anything about it, I am trying to get a mapped file image base from its optional header found in the PE header but the value in the ImageBase is 0?
The file I am trying to get this value from is a 64 bit executable (PE64), so what I am doing is I open the file with (CreateFileW function), then I map it using (CreateFileMappingW and MapViewOfFile functions), then I get the PE Header file with these functions:
IMAGE_DOS_HEADER* FileUtils_GetFileDOSHeader (void* Arg_FileViewMap) {
if (Arg_FileViewMap != NULL) {
return (IMAGE_DOS_HEADER*) Arg_FileViewMap;
}
return NULL;
}
IMAGE_NT_HEADERS* FileUtils_GetFilePEHeader (void* Arg_FileViewMap) {
if (Arg_FileViewMap != NULL) {
IMAGE_DOS_HEADER* Func_FileDOSHeader = FileUtils_GetFileDOSHeader(Arg_FileViewMap);
if (Func_FileDOSHeader != NULL) {
return (IMAGE_NT_HEADERS*) ((INT64) Func_FileDOSHeader + Func_FileDOSHeader->e_lfanew);
}
}
return NULL;
}
Then I use this function to get the optional header or do it directly, same result:
IMAGE_OPTIONAL_HEADER* FileUtils_GetFileOptionalHeader (void* Arg_FileViewMap) {
if (Arg_FileViewMap != NULL) {
IMAGE_NT_HEADERS* Arg_FilePEHeader = FileUtils_GetFilePEHeader(Arg_FileViewMap);
if (Arg_FilePEHeader != NULL) {
return (IMAGE_OPTIONAL_HEADER*) &Arg_FilePEHeader->OptionalHeader;
}
}
return NULL;
}
Then I try to get value and print it out so I would know that its not 0 like so:
wprintf(L"File image base: 0x%015X\n", FileUtils_GetFileOptionalHeader(Func_TargetFileViewMap)->ImageBase);
That is all! Once I compile this code for 64bit and run it, it prints out 0 but it should give me 0x00000010000000, so what is wrong here? The value does print out correctly, I made sure that the value is indeed 0 a lot of times.
Now things to note:
Some executables do give me the ImageBase value, but most of them give me 0 even though that is wrong, for example I open notepad and that gives me 0 but the value should be 0x00000010000000, and to show you that here is a screenshot of what CFF Explorer sees: (http://prntscr.com/) <- Click
It appears that all other values are correct except the ImageBase that is 0 for some reason, if I print out the EntryPoint then the value does match with what the CFF Explorer tells me.
I am using GCC (From MinGW-w64) compiler (C Programming Language) for this
I am not aware of any other invalid values in other headers, its just the ImageBase getting me frustrated.
A quick thing, if you also need to know what the function parameters for opening and mapping the file are then here they are:
HANDLE Func_TargetFile = CreateFileW((wchar_t*) & Func_ConsoleCommand, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
HANDLE Func_TargetFileMapping = CreateFileMappingW(Func_TargetFile, NULL, PAGE_READWRITE, 0, 0, NULL);
void* Func_TargetFileViewMap = MapViewOfFile(Func_TargetFileMapping, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);
That is all, once again if you are confused of what my question is: Why does the IMAGE_OPTIONAL_HEADER ImageBase gives me a value of 0 even though all other values in the header seem to match what CFF Explorer shows me? - Thank you
PS: I will check consistently, if you need more information then comment below.
I have solved the mistery, it was in the GetFilePEHeader function! The printed out value is now: 0x000000005F5E100
The issue was with the casting, this line of code:
return (IMAGE_NT_HEADERS*) ((char*) (Func_FileDOSHeader) + Func_FileDOSHeader->e_lfanew);
Here is the fixed function:
IMAGE_NT_HEADERS* FileUtils_GetFilePEHeader (void* Arg_FileViewMap) {
if (Arg_FileViewMap != NULL) {
IMAGE_DOS_HEADER* Func_FileDOSHeader = FileUtils_GetFileDOSHeader(Arg_FileViewMap);
if (Func_FileDOSHeader != NULL) {
return (IMAGE_NT_HEADERS*) ((INT64) Func_FileDOSHeader + Func_FileDOSHeader->e_lfanew);
}
}
return NULL;
}
Thank you all for all of your help, this was quite a dumb issue. It took me 3 days to figure this out.
I want to read from an RTP stream, but when I specify "test.sdp" to avformat_open_input() I get this message:
[rtp # 03928900] Protocol not on whitelist 'file'!
Failed: cannot open input.
avformat_open_input() fail: Invalid data found when processing input
Normally if I were using ffplay on the console, I would add the option -protocol_whitelist file,udp,rtp and it would work fine.
So I tried this:
AVDictionary *d = NULL;
av_dict_set(&d, "protocol_whitelist", "file, udp, rtp", 0);
ret = avformat_open_input(&inFormatCtx, filename, NULL, &d);
But the same message still pops up. Any ideas?
This is awkward...
avformat_open_input failed because I have white spaces. Removing the whitespaces now work.
av_dict_set(&d, "protocol_whitelist", "file,udp,rtp", 0);
EDIT: This answer works up to some version. You should use the options parameter of avformat_open_input as described in bot1131357's answer
I'm not totally sure about this, but I believe this options go into the AVFormatContext
AVFormatContext* formatContext = avformat_alloc_context();
formatContext->protocol_whitelist = "file,udp,rtp";
if (avformat_open_input(&formatContext, uri.c_str(), NULL, NULL) != 0) {
return EXIT_FAILURE;
}
Take a look at the cvs log of this change:
https://ffmpeg.org/pipermail/ffmpeg-cvslog/2016-March/098694.html
I have a function that writes an XML document to a buffer using the libxml2 writer, but when I try to parse the document from memory using xmlParseMemory, it only returns parser errors. I have also tried writing the document to a file and parsing it using xmlParseFile and it parses successfully.
This is how I initialize the writer and buffer for the xml document.
int rc, i = 0;
xmlTextWriterPtr writer;
xmlBufferPtr buf;
// Create a new XML buffer, to which the XML document will be written
buf = xmlBufferCreate();
if (buf == NULL)
{
printf("testXmlwriterMemory: Error creating the xml buffer\n");
return;
}
// Create a new XmlWriter for memory, with no compression.
// Remark: there is no compression for this kind of xmlTextWriter
writer = xmlNewTextWriterMemory(buf, 0);
if (writer == NULL)
{
printf("testXmlwriterMemory: Error creating the xml writer\n");
return;
}
// Start the document with the xml default for the version,
// encoding UTF-8 and the default for the standalone
// declaration.
rc = xmlTextWriterStartDocument(writer, NULL, ENCODING, NULL);
if (rc < 0)
{
printf
("testXmlwriterMemory: Error at xmlTextWriterStartDocument\n");
return;
}
I pass the xml document to another function to be validated using
int ret = validateXML(buf->content);
Here is the first part of validateXML
int validateXML(char *buffer)
{
xmlDocPtr doc;
xmlSchemaPtr schema = NULL;
xmlSchemaParserCtxtPtr ctxt;
char *XSDFileName = XSDFILE;
char *XMLFile = buffer;
int ret = 1;
doc = xmlReadMemory(XMLFile, sizeof(XMLFile), "noname.xml", NULL, 0);
doc is always NULL after calling this function, which means that it failed to parse the document.
Here are the errors that running the program returns
Entity: line 1: parser error : ParsePI: PI xm space expected
<?xm
^
Entity: line 1: parser error : ParsePI: PI xm never end ...
<?xm
^
Entity: line 1: parser error : Start tag expected, '<' not found
<?xm
^
I have been unable to figure this out for quite a while now and I am out of ideas. If anyone has any, I would be grateful if you would share it.
You are using sizeof to determine the size of the xml data. For a char pointer that is always going to return 4. What you probably need is strlen.
doc = xmlReadMemory(XMLFile, strlen(XMLFile), "noname.xml", NULL, 0);
I'm trying to archive files for a cross-platform application, and it looks like Minizip (built on zlib) is about as portable as archivers come.
When I try to run the following dummy code, however, I get a system error [my executable] has stopped working. Windows can check online for a solution to the problem.
Can anyone help me see how to use this library? — (there's no doc or tutorial anywhere that I can find)
zip_fileinfo zfi;
int main()
{
zipFile zf = zipOpen("myarch.zip",APPEND_STATUS_ADDINZIP);
int ret = zipOpenNewFileInZip(zf,
"myfile.txt",
&zfi,
NULL, 0,
NULL, 0,
"my comment for this interior file",
Z_DEFLATED,
Z_NO_COMPRESSION
);
zipCloseFileInZip(zf);
zipClose(zf, "my comment for exterior file");
return 0;
}
Specs: Msys + MinGW, Windows 7, using zlibwapi.dll from zlib125dll.zip/dll32
Since I found this question via Google and it didn't contain any complete, working code, I am providing some here for future visitors.
int CreateZipFile (std::vector<wstring> paths)
{
zipFile zf = zipOpen(std::string(destinationPath.begin(), destinationPath.end()).c_str(), APPEND_STATUS_CREATE);
if (zf == NULL)
return 1;
bool _return = true;
for (size_t i = 0; i < paths.size(); i++)
{
std::fstream file(paths[i].c_str(), std::ios::binary | std::ios::in);
if (file.is_open())
{
file.seekg(0, std::ios::end);
long size = file.tellg();
file.seekg(0, std::ios::beg);
std::vector<char> buffer(size);
if (size == 0 || file.read(&buffer[0], size))
{
zip_fileinfo zfi = { 0 };
std::wstring fileName = paths[i].substr(paths[i].rfind('\\')+1);
if (S_OK == zipOpenNewFileInZip(zf, std::string(fileName.begin(), fileName.end()).c_str(), &zfi, NULL, 0, NULL, 0, NULL, Z_DEFLATED, Z_DEFAULT_COMPRESSION))
{
if (zipWriteInFileInZip(zf, size == 0 ? "" : &buffer[0], size))
_return = false;
if (zipCloseFileInZip(zf))
_return = false;
file.close();
continue;
}
}
file.close();
}
_return = false;
}
if (zipClose(zf, NULL))
return 3;
if (!_return)
return 4;
return S_OK;
}
The minizip library does come with examples; minizip.c for zipping and miniunz.c for unzipping. Both are command line utilities that show how to use the library. They are a mess though.
You also need to fill the zfi zip_fileinfo. At the very least you should initialize the structure to zero. zfi contains information about the file you want to store using zipOpenNewFileInZip. The structure should contain the date and attributes of "myfile.txt".
I recommend using PKWARE Desktop to diagnosis zip issues. It shows the structure/properties of the files in the ZIP and the ZIP file itself. When I opened the myarch.zip it told me there were errors. I drilled down into the file properties and found that the attributes were off.
The minizip lib is well documented. Just open the zip.h for details.
I can tell you here, you may have passed a wrong parameter for zipOpen. (APPEND_STATUS_ADDINZIP requires an existing zip file!)
Also, please check whether zipOpen returns a valid zipFile handle.
I'm in the debugging phase of writing my text editor using gtk+ 2.0 & gtksourceview 2.0. When I open certain files (previously edited in geany, and usually python files) the editor crashes with the following output:
(ledit:23515): Gtk-CRITICAL **: IA__gtk_text_buffer_set_text: assertion `GTK_IS_TEXT_BUFFER (buffer)' failed
**
GLib:ERROR:gutf8.c:1915:_g_utf8_make_valid: assertion failed: (g_utf8_validate (string->str, -1, NULL))
Aborted
I've tried to trap this error as follows:
char *path,*string;
GtkTextBuffer *tbuffer;
gsize length = -1;
path = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dialog));
g_file_get_contents(path,&string,&length,NULL);
if (g_utf8_validate(string,length,NULL))
{
...
gtk_text_buffer_set_text(tbuffer,string,-1);
...
}
else
{
printf("invalid utf-8 data\n");
}
but this fails to work. I have two questions:
why did this fail to trap the error?
what else can I do to make the string valid utf-8 on the fly?
It turns out I was trying to trap the error on the wrong function. The function that was throwing the error was g_file_get_contents. I modified the code block as shown below, and the problem files are now opening fine, which I am kind of puzzled by, since it is still perfoming the same function that was throwing the error, but now it is in the condition of the if statement, and it works fine???
char *path,*string;
GtkTextBuffer *tbuffer;
gsize length = -1;
path = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dialog));
if ( g_file_get_contents(path,&string,&length,NULL) )
{
...
gtk_text_buffer_set_text(tbuffer,string,-1);
...
}
else
{
printf("file did not open\n");
}