Thread: Reading a binary file into a buffer including nulls

I am attempting to read a binary file into a buffer but the file contains nulls (it's a TIFF file). I need to keep the nulls but the buffer is getting null-terminated as soon as it encounters one. How do I keep the nulls in the buffer and everything that comes after them?

Code:

// Read the file into a buffer
unsigned char *fileBuf;
FILE *ucmFile = NULL;
int fileSize, result;

if ((ucmFile = fopen(szFileNamePath, "rb")) == NULL) {
     iRet = 8;
     strcpy(outResponse, "Error: Unable to open ");
     strcat(outResponse, szFileNamePath); 
} else {
     fileSize = getFileSize(ucmFile);
     fileBuf = (unsigned char*) malloc(sizeof(char)*fileSize);
     result = fread(fileBuf, 1, fileSize, ucmFile);
     if (result != fileSize) {
          iRet = 8;
          strcpy(outResponse, "Error: Unable to read ");
          strcat(outResponse, szFileNamePath); 
     }
     fclose(ucmFile); 
}

I didn't show all of the field definitions or the getFileSize method. The fread command is reading into fileBuf, which is defined as an unsigned char*. fileBuf only contains data up until the first null.

Thanks for your help!

Sorry about the mispost. I will repost in the C forum. I am using VC++ though so if you have a C++ solution, that could work for me. I'm not getting far enough to use mem functions vs str functions because my buffer area is getting null-terminated. The strcpy and strcat functions you see in my code are just to populate status message fields and don't involve my file buffer. I will also try fstream rather than FILE and see if that helps. Thanks!

Thank you for the reply. I requested that the thread be moved to the C forum. In the meantime, I created a very simple exe using fstream rather than FILE. The only thing this exe does is read a file into a buffer. There are no strxxx functions anywhere. I still have the same problem. The buffer only contains data up until the first null.

Code:

int main(int argc, char* argv[])
{
 string fileBuf;
 ifstream ucmFile("c:\\ucm.tif", ios::in | ios::binary);
 if (ucmFile) {
  ucmFile.seekg(0, ios::end);
  fileBuf.resize(ucmFile.tellg());
  ucmFile.seekg(0, ios::beg);
  ucmFile.read(&fileBuf[0], fileBuf.size());
  ucmFile.close();
 }
 return 0;
}

How do you know that the buffer only contains data upto the first nul? How did you view this buffer? If your data contains embedded nul you can't use any of the string functions. You will need to loop through the entire buffer printing it out character by character.

Jim

Oh, I see. I was stepping through the code in Visual Studio and when the buffer was populated, I moused over to see what was in there. I guess it was only showing me up until the null but maybe it really had the whole thing. I will look byte by byte. Thank you!