File descriptor support¶
-
class
jeepney.
FileDescriptor
(fd)[source]¶ A file descriptor received in a D-Bus message
This wrapper helps ensure that the file descriptor is closed exactly once. If you don’t explicitly convert or close the FileDescriptor object, it will close its file descriptor when it goes out of scope, and emit a ResourceWarning.
-
to_file
(mode, buffering=-1, encoding=None, errors=None, newline=None)[source]¶ Convert to a Python file object:
with fd.to_file('w') as f: f.write('xyz')
The arguments are the same as for the builtin
open()
function.The
FileDescriptor
can’t be used after calling this. Closing the file object will also close the file descriptor.Note
If the descriptor does not refer to a regular file, or it doesn’t have the right access mode, you may get strange behaviour or errors while using it.
You can use
os.stat()
and thestat
module to check the type of object the descriptor refers to, andfcntl.fcntl()
to check the access mode, e.g.:stat.S_ISREG(os.stat(fd.fileno()).st_mode) # Regular file? status_flags = fcntl.fcntl(fd, fcntl.F_GETFL) (status_flags & os.O_ACCMODE) == os.O_RDONLY # Read-only?
-
to_socket
()[source]¶ Convert to a socket object
This returns a standard library
socket.socket()
object:with fd.to_socket() as sock: b = sock.sendall(b'xyz')
The wrapper object can’t be used after calling this. Closing the socket object will also close the file descriptor.
-
to_raw_fd
()[source]¶ Convert to the low-level integer file descriptor:
raw_fd = fd.to_raw_fd() os.write(raw_fd, b'xyz') os.close(raw_fd)
The
FileDescriptor
can’t be used after calling this. The caller is responsible for closing the file descriptor.
-
fileno
()[source]¶ Get the integer file descriptor
This does not change the state of the
FileDescriptor
object, unlike theto_*
methods.
-
-
exception
jeepney.
NoFDError
[source]¶ Raised by
FileDescriptor
methods if it was already closed/converted