filedes 0.1.1

Work with file descriptors in a more human way

fdinfo

fdinfo is a python library for using file descriptors in a more intuitive way.

Examples

Creating a socket with SO_REUSEADR (or SO_REUSEPORT on BSD):

from filedes import FD
s = socket.socket()
FD(s).socket.set_reuse()

Enabling non-blocking mode on a PIPE

import os
from filedes import FD
r, w = os.pipe()
FD(r).set_nonblocking()

Disabling the close on execute bit for a temporary file

import tempfile
from filedes import FD
tf = tempfile.NamedTemporaryFile()
FD(tf).set_cloexec(False)

Listing the open FDs and their types of the current PID:

from filedes import FD, get_open_fds
for fd in get_open_fds():
    print fd, FD(fd).typestr

Sending fds to another process over a unix socket

from filedes import FD

# Send a single FD
FD(sock).socket.send_fd(an_fd)

# Or for multiple FDs
FD(sock).socket.send_fds(multiple_fds)

# To receive one fd (in a different pid)
an_fd = FD(sock).socket.recv_fd()

# To receive multiple fds (in a different pid)
two_fds = FD(sock).socket.recv_fds(2)

Key features

• Get detailed info about fds in both the local as well as external processes
• Perform fcntl and io operations directly on descriptor objects
• Unittest helper class for making sure your tests don’t leak fds or threads.
• Set various fd flags in a more native way, such as fd.set_cloexec() or fd.set_nonblocking()
• Socket helpers let you set socket options in a more native way, such as fd.socket.set_reuse()
• A Popen() subclass with a more intelligent close_fds for systems with a high fs.file-max set

Platforms

fdinfo is primarily developed on linux, but it doesn’t work just there. It has been tested on the following platforms:

• linux
• OSX

Developing for Darwin is tricky since there is no procfs, so some operations on filedescriptors in different pids may not work as desired