Read data from a stream at the current seek offset.


#include <zircon/syscalls.h>

zx_status_t zx_stream_readv(zx_handle_t handle,
                            uint32_t options,
                            zx_iovec_t* vector,
                            size_t num_vector,
                            size_t* actual);


zx_stream_readv() attempts to read bytes from the stream, starting at the current seek offset, into the buffers specified by vector and num_vector. If successful, the number of bytes actually read are return via actual.

If the current seek offset is beyond the end of the stream, zx_stream_readv() will succeed in reading zero bytes.

If a NULL actual is passed in, it will be ignored.

Advances the seek offset of the stream by the actual number of bytes read. If the read fails, the seek offset could either remain the same or have been changed to an unspecified value.

If the contents of vector change during this operation, if any of the buffers overlap, or if any of the buffers overlap vector, the behavior is unspecified.

options is reserved for future use and must be 0.


handle must be of type ZX_OBJ_TYPE_STREAM and have ZX_RIGHT_READ.

Return value

zx_stream_readv() returns ZX_OK on success, and writes into actual (if non-NULL) the exact number of bytes read.


ZX_ERR_BAD_HANDLE handle is not a valid handle.

ZX_ERR_WRONG_TYPE handle is not a stream handle.

ZX_ERR_ACCESS_DENIED handle does not have the ZX_RIGHT_READ right.

ZX_ERR_INVALID_ARGS vector is an invalid zx_iovec_t or options is nonzero.

ZX_ERR_NOT_FOUND the vector address, or an address specified within vector does not map to address in address space.

ZX_ERR_BAD_STATE the underlying data source cannot be read.

See also