Determines the MIME type from the data provided.
Syntax
HRESULT FindMimeFromData( LPBC pBC, LPCWSTR pwzUrl, LPVOID pBuffer, DWORD cbSize, LPCWSTR pwzMimeProposed, DWORD dwMimeFlags, LPWSTR *ppwzMimeOut, DWORD dwReserved );
Parameters
pBC A pointer to the IBindCtx interface. Can be set to NULL.pwzUrl A pointer to a string value that contains the URL of the data. Can be set to NULL if pBuffer contains the data to be sniffed. pBuffer A pointer to the buffer that contains the data to be sniffed. Can be set to NULL if pwzUrl contains a valid URL. cbSize An unsigned long integer value that contains the size of the buffer. pwzMimeProposed A pointer to a string value that contains the proposed MIME type. This value is authoritative if nothing else can be determined about type. Can be set to NULL. dwMimeFlags One of the following required values: FMFD_DEFAULTNo flags specified. Use default behavior for the function. FMFD_URLASFILENAMETreat the specified pwzUrl as a file name. FMFD_ENABLEMIMESNIFFINGMicrosoft Internet Explorer 6 for Windows XP Service Pack 2 (SP2) and later. Use MIME-type detection even if FEATURE_MIME_SNIFFING is detected. Usually, this feature control key would disable MIME-type detection. FMFD_IGNOREMIMETEXTPLAINInternet Explorer 6 for Windows XP SP2 and later. Perform MIME-type detection if "text/plain" is proposed, even if data sniffing is otherwise disabled. Plain text may be converted to text/html if HTML tags are detected. FMFD_SERVERMIMEWindows Internet Explorer 8. Use the authoritative MIME type specified in pwzMimeProposed. Unless FMFD_IGNOREMIMETEXTPLAIN is specified, no data sniffing is performed. ppwzMimeOut The address of a string value that receives the suggested MIME type. dwReserved Reserved. Must be set to 0.
FMFD_DEFAULT
FMFD_URLASFILENAME
FMFD_ENABLEMIMESNIFFING
FMFD_IGNOREMIMETEXTPLAIN
text/html
FMFD_SERVERMIME
Return Value
Returns one of the following values.S_OKThe operation completed successfully.E_FAILThe operation failed.E_INVALIDARGOne or more arguments are invalid.E_OUTOFMEMORYThere is insufficient memory to complete the operation.
Returns one of the following values.
Remarks
MIME type detection, or "data sniffing," refers to the process of determining an appropriate MIME type from binary data. The final result depends on a combination of server-supplied MIME type headers, file extension, and/or the data itself. Usually, only the first 256 bytes of data are significant. For more information and a complete list of recognized MIME types, see MIME Type Detection in Internet Explorer. If pwzUrl is specified without data to be sniffed (pBuffer), the file extension determines the MIME type. If the file extension cannot be mapped to a MIME type, this method returns E_FAIL unless a proposed MIME type is supplied in pwzMimeProposed. After ppwzMimeOut returns and is read, the memory allocated for it should be freed with the operator delete function. Internet Explorer 8 and later. FindMimeFromData will not promote image types to "text/html" even if the data is lacking magic numbers (signature bytes).
MIME type detection, or "data sniffing," refers to the process of determining an appropriate MIME type from binary data. The final result depends on a combination of server-supplied MIME type headers, file extension, and/or the data itself. Usually, only the first 256 bytes of data are significant. For more information and a complete list of recognized MIME types, see MIME Type Detection in Internet Explorer.
If pwzUrl is specified without data to be sniffed (pBuffer), the file extension determines the MIME type. If the file extension cannot be mapped to a MIME type, this method returns E_FAIL unless a proposed MIME type is supplied in pwzMimeProposed.
After ppwzMimeOut returns and is read, the memory allocated for it should be freed with the operator delete function.
Internet Explorer 8 and later. FindMimeFromData will not promote image types to "text/html" even if the data is lacking magic numbers (signature bytes).
Function Information
Stock Implementationurlmon.dllCustom ImplementationNoHeaderUrlmon.hImport libraryUrlmon.libMinimum availabilityInternet Explorer 4.0Minimum operating systems Windows NT 4.0, Windows 95, Windows CE 2.12
This should really be part of the documentation for this function:
"MIME Type Detection in Internet Explorer" http://msdn2.microsoft.com/en-us/library/ms775147.aspx
The title of the article is a bit of a misnomer--it specifically deals with how FindMimeFromData() works.