os.fstat(fd) Get the status of the file descriptor fd. Return a stat_result object. As of Python 3.3, this is equivalent to os.stat(fd). See also The stat() function.

os.fsencode(filename) Encode filename to the filesystem encoding with 'surrogateescape' error handler, or 'strict' on Windows; return bytes unchanged. fsdecode() is the reverse function. New in version 3.2.

os.fsdecode(filename) Decode filename from the filesystem encoding with 'surrogateescape' error handler, or 'strict' on Windows; return str unchanged. fsencode() is the reverse function. New in version 3.2.

os.fpathconf(fd, name) Return system configuration information relevant to an open file. name specifies the configuration value to retrieve; it may be a string which is the name of a defined system value; these names are specified in a number of standards (POSIX.1, Unix 95, Unix 98, and others). Some platforms define additional names as well. The names known to the host operating system are given in the pathconf_names dictionary. For configuration variables not included in that mapping, pass

os.forkpty() Fork a child process, using a new pseudo-terminal as the child’s controlling terminal. Return a pair of (pid, fd), where pid is 0 in the child, the new child’s process id in the parent, and fd is the file descriptor of the master end of the pseudo-terminal. For a more portable approach, use the pty module. If an error occurs OSError is raised. Availability: some flavors of Unix.

os.fork() Fork a child process. Return 0 in the child and the child’s process id in the parent. If an error occurs OSError is raised. Note that some platforms including FreeBSD <= 6.3 and Cygwin have known issues when using fork() from a thread. Warning See ssl for applications that use the SSL module with fork(). Availability: Unix.

os.fdopen(fd, *args, **kwargs) Return an open file object connected to the file descriptor fd. This is an alias of the open() built-in function and accepts the same arguments. The only difference is that the first argument of fdopen() must always be an integer.

os.fdatasync(fd) Force write of file with filedescriptor fd to disk. Does not force update of metadata. Availability: Unix. Note This function is not available on MacOS.

os.fchown(fd, uid, gid) Change the owner and group id of the file given by fd to the numeric uid and gid. To leave one of the ids unchanged, set it to -1. See chown(). As of Python 3.3, this is equivalent to os.chown(fd, uid, gid). Availability: Unix.

os.fchmod(fd, mode) Change the mode of the file given by fd to the numeric mode. See the docs for chmod() for possible values of mode. As of Python 3.3, this is equivalent to os.chmod(fd, mode). Availability: Unix.