dataStream.readRawData(pBuf, fileLen);

This function reads raw binary data from the data stream into a buffer specified by pBuf, with the length of the data to be read specified by fileLen.

Here is an example of how this function can be used:

QDataStream dataStream(&file);  // Create a QDataStream object to read from a file
char* pBuf = new char[fileLen];  // Create a buffer to store the read data
dataStream.readRawData(pBuf, fileLen);  // Read fileLen bytes of data from the data stream into pBuf

In this example, the data stream is created with a reference to a file, and a buffer of size fileLen is allocated to store the read data. The readRawData() function is then called to read fileLen bytes of raw binary data from the data stream into the buffer.

Note that the readRawData() function does not perform any byte order conversions or data type conversions, so the data read from the stream must be interpreted based on the expected data format.