Function dpiLob_readBytes 

pub unsafe extern "C" fn dpiLob_readBytes(
    lob: *mut dpiLob,
    offset: u64,
    amount: u64,
    value: *mut c_char,
    valueLength: *mut u64,
) -> c_int

Reads data from the LOB at the specified offset into the provided buffer.

The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.

WARNING: for historical reasons, Oracle stores CLOBs and NCLOBs using the UTF-16 encoding, regardless of what encoding is otherwise in use by the database. The number of characters, however, is defined by the number of UCS-2 codepoints. For this reason, if a character requires more than one UCS-2 codepoint, care must be taken to account for them in both the offset and amount parameters.