# posix - pydoc - phpman

Help on built-in module posix:

## NAME
    posix

## MODULE REFERENCE
    <https://docs.python.org/3.10/library/posix.html>

    The following documentation is automatically generated from the Python
    source files.  It may be incomplete, incorrect or include features that
    are considered implementation detail and may vary between Python
    implementations.  When in doubt, consult the module reference at the
    location listed above.

## DESCRIPTION
    This module provides access to operating system functionality that is
    standardized by the C Standard and the POSIX standard (a thinly
    disguised Unix interface).  Refer to the library manual and
    corresponding Unix manual entries for more information on calls.

## CLASSES
    builtins.object
        DirEntry
    builtins.tuple(builtins.object)
        sched_param
        times_result
        uname_result
        waitid_result

### class DirEntry
     |  Methods defined here:
     |
     |  __fspath__(self, /)
     |      Returns the path for the entry.
     |
     |  __repr__(self, /)
     |      Return repr(self).
     |
     |  inode(self, /)
     |      Return inode of the entry; cached per entry.
     |
     |  is_dir(self, /, *, follow_symlinks=True)
     |      Return True if the entry is a directory; cached per entry.
     |
     |  is_file(self, /, *, follow_symlinks=True)
     |      Return True if the entry is a file; cached per entry.
     |
     |  is_symlink(self, /)
     |      Return True if the entry is a symbolic link; cached per entry.
     |
     |  stat(self, /, *, follow_symlinks=True)
     |      Return stat_result object for the entry; cached per entry.
     |
     |  ----------------------------------------------------------------------
     |  Class methods defined here:
     |
     |  __class_getitem__(...) from builtins.type
     |      See PEP 585
     |
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |
     |  name
     |      the entry's base filename, relative to scandir() "path" argument
     |
     |  path
     |      the entry's full path name; equivalent to os.path.join(scandir_path, entry.name)

### class sched_param
     |  sched_param(sched_priority)
     |
     |  Currently has only one field: sched_priority
     |
     |  sched_priority
     |    A scheduling parameter.
     |
     |  Method resolution order:
     |      sched_param
     |      builtins.tuple
     |      builtins.object
     |
     |  Methods defined here:
     |
     |  __reduce__(...)
     |      Helper for pickle.
     |
     |  __repr__(self, /)
     |      Return repr(self).
     |
     |  ----------------------------------------------------------------------
     |  Static methods defined here:
     |
     |  __new__(*args, **kwargs) from builtins.type
     |      Create and return a new object.  See help(type) for accurate signature.
     |
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |
     |  sched_priority
     |      the scheduling priority
     |
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |
     |  __match_args__ = ('sched_priority',)
     |
     |  n_fields = 1
     |
     |  n_sequence_fields = 1
     |
     |  n_unnamed_fields = 0
     |
     |  ----------------------------------------------------------------------
     |  Methods inherited from builtins.tuple:
     |
     |  __add__(self, value, /)
     |      Return self+value.
     |
     |  __contains__(self, key, /)
     |      Return key in self.
     |
     |  __eq__(self, value, /)
     |      Return self==value.
     |
     |  __ge__(self, value, /)
     |      Return self>=value.
     |
     |  __getattribute__(self, name, /)
     |      Return getattr(self, name).
     |
     |  __getitem__(self, key, /)
     |      Return self[key].
     |
     |  __getnewargs__(self, /)
     |
     |  __gt__(self, value, /)
     |      Return self>value.
     |
     |  __hash__(self, /)
     |      Return hash(self).
     |
     |  __iter__(self, /)
     |      Implement iter(self).
     |
     |  __le__(self, value, /)
     |      Return self<=value.
     |
     |  __len__(self, /)
     |      Return len(self).
     |
     |  __lt__(self, value, /)
     |      Return self<value.
     |
     |  __mul__(self, value, /)
     |      Return self*value.
     |
     |  __ne__(self, value, /)
     |      Return self!=value.
     |
     |  __rmul__(self, value, /)
     |      Return value*self.
     |
     |  count(self, value, /)
     |      Return number of occurrences of value.
     |
     |  index(self, value, start=0, stop=9223372036854775807, /)
     |      Return first index of value.
     |
     |      Raises ValueError if the value is not present.
     |
     |  ----------------------------------------------------------------------
     |  Class methods inherited from builtins.tuple:
     |
     |  __class_getitem__(...) from builtins.type
     |      See PEP 585

### class times_result
     |  times_result(iterable=(), /)
     |
     |  times_result: Result from os.times().
     |
     |  This object may be accessed either as a tuple of
     |    (user, system, children_user, children_system, elapsed),
     |  or via the attributes user, system, children_user, children_system,
     |  and elapsed.
     |
     |  See os.times for more information.
     |
     |  Method resolution order:
     |      times_result
     |      builtins.tuple
     |      builtins.object
     |
     |  Methods defined here:
     |
     |  __reduce__(...)
     |      Helper for pickle.
     |
     |  __repr__(self, /)
     |      Return repr(self).
     |
     |  ----------------------------------------------------------------------
     |  Static methods defined here:
     |
     |  __new__(*args, **kwargs) from builtins.type
     |      Create and return a new object.  See help(type) for accurate signature.
     |
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |
     |  children_system
     |      system time of children
     |
     |  children_user
     |      user time of children
     |
     |  elapsed
     |      elapsed time since an arbitrary point in the past
     |
     |  system
     |      system time
     |
     |  user
     |      user time
     |
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |
     |  __match_args__ = ('user', 'system', 'children_user', 'children_system'...
     |
     |  n_fields = 5
     |
     |  n_sequence_fields = 5
     |
     |  n_unnamed_fields = 0
     |
     |  ----------------------------------------------------------------------
     |  Methods inherited from builtins.tuple:
     |
     |  __add__(self, value, /)
     |      Return self+value.
     |
     |  __contains__(self, key, /)
     |      Return key in self.
     |
     |  __eq__(self, value, /)
     |      Return self==value.
     |
     |  __ge__(self, value, /)
     |      Return self>=value.
     |
     |  __getattribute__(self, name, /)
     |      Return getattr(self, name).
     |
     |  __getitem__(self, key, /)
     |      Return self[key].
     |
     |  __getnewargs__(self, /)
     |
     |  __gt__(self, value, /)
     |      Return self>value.
     |
     |  __hash__(self, /)
     |      Return hash(self).
     |
     |  __iter__(self, /)
     |      Implement iter(self).
     |
     |  __le__(self, value, /)
     |      Return self<=value.
     |
     |  __len__(self, /)
     |      Return len(self).
     |
     |  __lt__(self, value, /)
     |      Return self<value.
     |
     |  __mul__(self, value, /)
     |      Return self*value.
     |
     |  __ne__(self, value, /)
     |      Return self!=value.
     |
     |  __rmul__(self, value, /)
     |      Return value*self.
     |
     |  count(self, value, /)
     |      Return number of occurrences of value.
     |
     |  index(self, value, start=0, stop=9223372036854775807, /)
     |      Return first index of value.
     |
     |      Raises ValueError if the value is not present.
     |
     |  ----------------------------------------------------------------------
     |  Class methods inherited from builtins.tuple:
     |
     |  __class_getitem__(...) from builtins.type
     |      See PEP 585

### class uname_result
     |  uname_result(iterable=(), /)
     |
     |  uname_result: Result from os.uname().
     |
     |  This object may be accessed either as a tuple of
     |    (sysname, nodename, release, version, machine),
     |  or via the attributes sysname, nodename, release, version, and machine.
     |
     |  See os.uname for more information.
     |
     |  Method resolution order:
     |      uname_result
     |      builtins.tuple
     |      builtins.object
     |
     |  Methods defined here:
     |
     |  __reduce__(...)
     |      Helper for pickle.
     |
     |  __repr__(self, /)
     |      Return repr(self).
     |
     |  ----------------------------------------------------------------------
     |  Static methods defined here:
     |
     |  __new__(*args, **kwargs) from builtins.type
     |      Create and return a new object.  See help(type) for accurate signature.
     |
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |
     |  machine
     |      hardware identifier
     |
     |  nodename
     |      name of machine on network (implementation-defined)
     |
     |  release
     |      operating system release
     |
     |  sysname
     |      operating system name
     |
     |  version
     |      operating system version
     |
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |
     |  __match_args__ = ('sysname', 'nodename', 'release', 'version', 'machin...
     |
     |  n_fields = 5
     |
     |  n_sequence_fields = 5
     |
     |  n_unnamed_fields = 0
     |
     |  ----------------------------------------------------------------------
     |  Methods inherited from builtins.tuple:
     |
     |  __add__(self, value, /)
     |      Return self+value.
     |
     |  __contains__(self, key, /)
     |      Return key in self.
     |
     |  __eq__(self, value, /)
     |      Return self==value.
     |
     |  __ge__(self, value, /)
     |      Return self>=value.
     |
     |  __getattribute__(self, name, /)
     |      Return getattr(self, name).
     |
     |  __getitem__(self, key, /)
     |      Return self[key].
     |
     |  __getnewargs__(self, /)
     |
     |  __gt__(self, value, /)
     |      Return self>value.
     |
     |  __hash__(self, /)
     |      Return hash(self).
     |
     |  __iter__(self, /)
     |      Implement iter(self).
     |
     |  __le__(self, value, /)
     |      Return self<=value.
     |
     |  __len__(self, /)
     |      Return len(self).
     |
     |  __lt__(self, value, /)
     |      Return self<value.
     |
     |  __mul__(self, value, /)
     |      Return self*value.
     |
     |  __ne__(self, value, /)
     |      Return self!=value.
     |
     |  __rmul__(self, value, /)
     |      Return value*self.
     |
     |  count(self, value, /)
     |      Return number of occurrences of value.
     |
     |  index(self, value, start=0, stop=9223372036854775807, /)
     |      Return first index of value.
     |
     |      Raises ValueError if the value is not present.
     |
     |  ----------------------------------------------------------------------
     |  Class methods inherited from builtins.tuple:
     |
     |  __class_getitem__(...) from builtins.type
     |      See PEP 585

### class waitid_result
     |  waitid_result(iterable=(), /)
     |
     |  waitid_result: Result from waitid.
     |
     |  This object may be accessed either as a tuple of
     |    (si_pid, si_uid, si_signo, si_status, si_code),
     |  or via the attributes si_pid, si_uid, and so on.
     |
     |  See os.waitid for more information.
     |
     |  Method resolution order:
     |      waitid_result
     |      builtins.tuple
     |      builtins.object
     |
     |  Methods defined here:
     |
     |  __reduce__(...)
     |      Helper for pickle.
     |
     |  __repr__(self, /)
     |      Return repr(self).
     |
     |  ----------------------------------------------------------------------
     |  Static methods defined here:
     |
     |  __new__(*args, **kwargs) from builtins.type
     |      Create and return a new object.  See help(type) for accurate signature.
     |
     |  ----------------------------------------------------------------------
     |  Data descriptors defined here:
     |
     |  si_code
     |
     |  si_pid
     |
     |  si_signo
     |
     |  si_status
     |
     |  si_uid
     |
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |
     |  __match_args__ = ('si_pid', 'si_uid', 'si_signo', 'si_status', 'si_cod...
     |
     |  n_fields = 5
     |
     |  n_sequence_fields = 5
     |
     |  n_unnamed_fields = 0
     |
     |  ----------------------------------------------------------------------
     |  Methods inherited from builtins.tuple:
     |
     |  __add__(self, value, /)
     |      Return self+value.
     |
     |  __contains__(self, key, /)
     |      Return key in self.
     |
     |  __eq__(self, value, /)
     |      Return self==value.
     |
     |  __ge__(self, value, /)
     |      Return self>=value.
     |
     |  __getattribute__(self, name, /)
     |      Return getattr(self, name).
     |
     |  __getitem__(self, key, /)
     |      Return self[key].
     |
     |  __getnewargs__(self, /)
     |
     |  __gt__(self, value, /)
     |      Return self>value.
     |
     |  __hash__(self, /)
     |      Return hash(self).
     |
     |  __iter__(self, /)
     |      Implement iter(self).
     |
     |  __le__(self, value, /)
     |      Return self<=value.
     |
     |  __len__(self, /)
     |      Return len(self).
     |
     |  __lt__(self, value, /)
     |      Return self<value.
     |
     |  __mul__(self, value, /)
     |      Return self*value.
     |
     |  __ne__(self, value, /)
     |      Return self!=value.
     |
     |  __rmul__(self, value, /)
     |      Return value*self.
     |
     |  count(self, value, /)
     |      Return number of occurrences of value.
     |
     |  index(self, value, start=0, stop=9223372036854775807, /)
     |      Return first index of value.
     |
     |      Raises ValueError if the value is not present.
     |
     |  ----------------------------------------------------------------------
     |  Class methods inherited from builtins.tuple:
     |
     |  __class_getitem__(...) from builtins.type
     |      See PEP 585

## FUNCTIONS
    WCOREDUMP(status, /)
        Return True if the process returning status was dumped to a core file.

    WEXITSTATUS(status)
        Return the process return code from status.

    WIFCONTINUED(status)
        Return True if a particular process was continued from a job control stop.

        Return True if the process returning status was continued from a
        job control stop.

    WIFEXITED(status)
        Return True if the process returning status exited via the exit() system call.

    WIFSIGNALED(status)
        Return True if the process returning status was terminated by a signal.

    WIFSTOPPED(status)
        Return True if the process returning status was stopped.

    WSTOPSIG(status)
        Return the signal that stopped the process that provided the status value.

    WTERMSIG(status)
        Return the signal that terminated the process that provided the status value.

### abort
        Abort the interpreter immediately.

        This function 'dumps core' or otherwise fails in the hardest way possible
        on the hosting operating system.  This function never returns.

### access
        Use the real uid/gid to test for access to a path.

          path
            Path to be tested; can be string, bytes, or a path-like object.
          mode
            Operating-system mode bitfield.  Can be F_OK to test existence,
            or the inclusive-OR of R_OK, W_OK, and X_OK.
          dir_fd
            If not None, it should be a file descriptor open to a directory,
            and path should be relative; path will then be relative to that
            directory.
          effective_ids
            If True, access will use the effective uid/gid instead of
            the real uid/gid.
          follow_symlinks
            If False, and the last element of the path is a symbolic link,
            access will examine the symbolic link itself instead of the file
            the link points to.

        dir_fd, effective_ids, and follow_symlinks may not be implemented
          on your platform.  If they are unavailable, using them will raise a
          NotImplementedError.

        Note that most operations will use the effective uid/gid, therefore this
          routine can be used in a suid/sgid environment to test if the invoking user
          has the specified access to the path.

### chdir
        Change the current working directory to the specified path.

        path may always be specified as a string.
        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.

### chmod
        Change the access permissions of a file.

          path
            Path to be modified.  May always be specified as a str, bytes, or a path-like object.
            On some platforms, path may also be specified as an open file descriptor.
            If this functionality is unavailable, using it raises an exception.
          mode
            Operating-system mode bitfield.
          dir_fd
            If not None, it should be a file descriptor open to a directory,
            and path should be relative; path will then be relative to that
            directory.
          follow_symlinks
            If False, and the last element of the path is a symbolic link,
            chmod will modify the symbolic link itself instead of the file
            the link points to.

        It is an error to use dir_fd or follow_symlinks when specifying path as
          an open file descriptor.
        dir_fd and follow_symlinks may not be implemented on your platform.
          If they are unavailable, using them will raise a NotImplementedError.

### chown
        Change the owner and group id of path to the numeric uid and gid.\

          path
            Path to be examined; can be string, bytes, a path-like object, or open-file-descriptor int.
          dir_fd
            If not None, it should be a file descriptor open to a directory,
            and path should be relative; path will then be relative to that
            directory.
          follow_symlinks
            If False, and the last element of the path is a symbolic link,
            stat will examine the symbolic link itself instead of the file
            the link points to.

        path may always be specified as a string.
        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.
        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, chown will modify the symbolic link itself instead of the file the
          link points to.
        It is an error to use dir_fd or follow_symlinks when specifying path as
          an open file descriptor.
        dir_fd and follow_symlinks may not be implemented on your platform.
          If they are unavailable, using them will raise a NotImplementedError.

### chroot
        Change root directory to path.

### close
        Close a file descriptor.

### closerange
        Closes all file descriptors in [fd_low, fd_high), ignoring errors.

### confstr
        Return a string-valued system configuration variable.

### copy_file_range
        Copy count bytes from one file descriptor to another.

          src
            Source file descriptor.
          dst
            Destination file descriptor.
          count
            Number of bytes to copy.
          offset_src
            Starting offset in src.
          offset_dst
            Starting offset in dst.

        If offset_src is None, then src is read from the current position;
        respectively for offset_dst.

### cpu_count
        Return the number of CPUs in the system; return None if indeterminable.

        This number is not equivalent to the number of CPUs the current process can
        use.  The number of usable CPUs can be obtained with
        ``len([os.sched_getaffinity(0)](https://www.chedong.com/phpMan.php/man/os.schedgetaffinity/0/markdown))``

### ctermid
        Return the name of the controlling terminal for this process.

### device_encoding
        Return a string describing the encoding of a terminal's file descriptor.

        The file descriptor must be attached to a terminal.
        If the device is not a terminal, return None.

### dup
        Return a duplicate of a file descriptor.

### dup2
        Duplicate file descriptor.

### eventfd
        Creates and returns an event notification file descriptor.

### eventfd_read
        Read eventfd value

### eventfd_write
        Write eventfd value.

### execv
        Execute an executable path with arguments, replacing current process.

        path
          Path of executable file.
        argv
          Tuple or list of strings.

### execve
        Execute an executable path with arguments, replacing current process.

        path
          Path of executable file.
        argv
          Tuple or list of strings.
        env
          Dictionary of strings mapping to strings.

### fchdir
        Change to the directory of the given file descriptor.

        fd must be opened on a directory, not a file.
        Equivalent to os.chdir(fd).

### fchmod
        Change the access permissions of the file given by file descriptor fd.

        Equivalent to os.chmod(fd, mode).

### fchown
        Change the owner and group id of the file specified by file descriptor.

        Equivalent to os.chown(fd, uid, gid).

### fdatasync
        Force write of fd to disk without forcing update of metadata.

### fork
        Fork a child process.

        Return 0 to child process and PID of child to parent process.

### forkpty
        Fork a new process with a new pseudo-terminal as controlling tty.

        Returns a tuple of (pid, master_fd).
        Like fork(), return pid of 0 to the child process,
        and pid of child to the parent process.
        To both, return fd of newly opened pseudo-terminal.

### fpathconf
        Return the configuration limit name for the file descriptor fd.

        If there is no limit, return -1.

### fspath
        Return the file system path representation of the object.

        If the object is str or bytes, then allow it to pass through as-is. If the
        object defines __fspath__(), then return the result of that method. All other
        types raise a TypeError.

### fstat
        Perform a stat system call on the given file descriptor.

        Like stat(), but for an open file descriptor.
        Equivalent to os.stat(fd).

### fstatvfs
        Perform an fstatvfs system call on the given fd.

        Equivalent to statvfs(fd).

### fsync
        Force write of fd to disk.

### ftruncate
        Truncate a file, specified by file descriptor, to a specific length.

### get_blocking
        Get the blocking mode of the file descriptor.

        Return False if the O_NONBLOCK flag is set, True if the flag is cleared.

### get_inheritable
        Get the close-on-exe flag of the specified file descriptor.

### get_terminal_size
        Return the size of the terminal window as (columns, lines).

        The optional argument fd (default standard output) specifies
        which file descriptor should be queried.

        If the file descriptor is not connected to a terminal, an OSError
        is thrown.

        This function will only be defined if an implementation is
        available for this system.

        shutil.get_terminal_size is the high-level function which should
        normally be used, os.get_terminal_size is the low-level implementation.

### getcwd
        Return a unicode string representing the current working directory.

### getcwdb
        Return a bytes string representing the current working directory.

### getegid
        Return the current process's effective group id.

### geteuid
        Return the current process's effective user id.

### getgid
        Return the current process's group id.

### getgrouplist
        Returns a list of groups to which a user belongs.

        user
          username to lookup
        group
          base group id of the user

### getgroups
        Return list of supplemental group IDs for the process.

### getloadavg
        Return average recent system load information.

        Return the number of processes in the system run queue averaged over
        the last 1, 5, and 15 minutes as a tuple of three floats.
        Raises OSError if the load average was unobtainable.

### getlogin
        Return the actual login name.

### getpgid
        Call the system call getpgid(), and return the result.

### getpgrp
        Return the current process group id.

### getpid
        Return the current process id.

### getppid
        Return the parent's process id.

        If the parent process has already exited, Windows machines will still
        return its id; others systems will return the id of the 'init' process (1).

### getpriority
        Return program scheduling priority.

### getrandom
        Obtain a series of random bytes.

### getresgid
        Return a tuple of the current process's real, effective, and saved group ids.

### getresuid
        Return a tuple of the current process's real, effective, and saved user ids.

### getsid
        Call the system call getsid(pid) and return the result.

### getuid
        Return the current process's user id.

### getxattr
        Return the value of extended attribute attribute on path.

        path may be either a string, a path-like object, or an open file descriptor.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, getxattr will examine the symbolic link itself instead of the file
          the link points to.

### initgroups
        Initialize the group access list.

        Call the system initgroups() to initialize the group access list with all of
        the groups of which the specified username is a member, plus the specified
        group id.

### isatty
        Return True if the fd is connected to a terminal.

        Return True if the file descriptor is an open file descriptor
        connected to the slave end of a terminal.

### kill
        Kill a process with a signal.

### killpg
        Kill a process group with a signal.

### lchown
        Change the owner and group id of path to the numeric uid and gid.

        This function will not follow symbolic links.
        Equivalent to os.chown(path, uid, gid, follow_symlinks=False).

### link
        Create a hard link to a file.

        If either src_dir_fd or dst_dir_fd is not None, it should be a file
          descriptor open to a directory, and the respective path string (src or dst)
          should be relative; the path will then be relative to that directory.
        If follow_symlinks is False, and the last element of src is a symbolic
          link, link will create a link to the symbolic link itself instead of the
          file the link points to.
        src_dir_fd, dst_dir_fd, and follow_symlinks may not be implemented on your
          platform.  If they are unavailable, using them will raise a
          NotImplementedError.

### listdir
        Return a list containing the names of the files in the directory.

        path can be specified as either str, bytes, or a path-like object.  If path is bytes,
          the filenames returned will also be bytes; in all other circumstances
          the filenames returned will be str.
        If path is None, uses the path='.'.
        On some platforms, path may also be specified as an open file descriptor;\
          the file descriptor must refer to a directory.
          If this functionality is unavailable, using it raises NotImplementedError.

        The list is in arbitrary order.  It does not include the special
        entries '.' and '..' even if they are present in the directory.

### listxattr
        Return a list of extended attributes on path.

        path may be either None, a string, a path-like object, or an open file descriptor.
        if path is None, listxattr will examine the current directory.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, listxattr will examine the symbolic link itself instead of the file
          the link points to.

### lockf
        Apply, test or remove a POSIX lock on an open file descriptor.

        fd
          An open file descriptor.
        command
          One of F_LOCK, F_TLOCK, F_ULOCK or F_TEST.
        length
          The number of bytes to lock, starting at the current position.

### lseek
        Set the position of a file descriptor.  Return the new position.

        Return the new cursor position in number of bytes
        relative to the beginning of the file.

### lstat
        Perform a stat system call on the given path, without following symbolic links.

        Like stat(), but do not follow symbolic links.
        Equivalent to stat(path, follow_symlinks=False).

### major
        Extracts a device major number from a raw device number.

### makedev
        Composes a raw device number from the major and minor device numbers.

### memfd_create

### minor
        Extracts a device minor number from a raw device number.

### mkdir
        Create a directory.

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

        The mode argument is ignored on Windows. Where it is used, the current umask
        value is first masked out.

### mkfifo
        Create a "fifo" (a POSIX named pipe).

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### mknod
        Create a node in the file system.

        Create a node in the file system (file, device special file or named pipe)
        at path.  mode specifies both the permissions to use and the
        type of node to be created, being combined (bitwise OR) with one of
        S_IFREG, S_IFCHR, S_IFBLK, and S_IFIFO.  If S_IFCHR or S_IFBLK is set on mode,
        device defines the newly created device special file (probably using
        os.makedev()).  Otherwise device is ignored.

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### nice
        Add increment to the priority of process and return the new priority.

### open
        Open a file for low level IO.  Returns a file descriptor (integer).

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### openpty
        Open a pseudo-terminal.

        Return a tuple of (master_fd, slave_fd) containing open file descriptors
        for both the master and slave ends.

### pathconf
        Return the configuration limit name for the file or directory path.

        If there is no limit, return -1.
        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.

### pidfd_open
        Return a file descriptor referring to the process *pid*.

        The descriptor can be used to perform process management without races and
        signals.

### pipe
        Create a pipe.

        Returns a tuple of two file descriptors:
          (read_fd, write_fd)

### pipe2
        Create a pipe with flags set atomically.

        Returns a tuple of two file descriptors:
          (read_fd, write_fd)

        flags can be constructed by ORing together one or more of these values:
        O_NONBLOCK, O_CLOEXEC.

### posix_fadvise
        Announce an intention to access data in a specific pattern.

        Announce an intention to access data in a specific pattern, thus allowing
        the kernel to make optimizations.
        The advice applies to the region of the file specified by fd starting at
        offset and continuing for length bytes.
        advice is one of POSIX_FADV_NORMAL, POSIX_FADV_SEQUENTIAL,
        POSIX_FADV_RANDOM, POSIX_FADV_NOREUSE, POSIX_FADV_WILLNEED, or
        POSIX_FADV_DONTNEED.

### posix_fallocate
        Ensure a file has allocated at least a particular number of bytes on disk.

        Ensure that the file specified by fd encompasses a range of bytes
        starting at offset bytes from the beginning and continuing for length bytes.

### posix_spawn
        Execute the program specified by path in a new process.

        path
          Path of executable file.
        argv
          Tuple or list of strings.
        env
          Dictionary of strings mapping to strings.
        file_actions
          A sequence of file action tuples.
        setpgroup
          The pgroup to use with the POSIX_SPAWN_SETPGROUP flag.
        resetids
          If the value is `true` the POSIX_SPAWN_RESETIDS will be activated.
        setsid
          If the value is `true` the POSIX_SPAWN_SETSID or POSIX_SPAWN_SETSID_NP will be activated.
        setsigmask
          The sigmask to use with the POSIX_SPAWN_SETSIGMASK flag.
        setsigdef
          The sigmask to use with the POSIX_SPAWN_SETSIGDEF flag.
        scheduler
          A tuple with the scheduler policy (optional) and parameters.

### posix_spawnp
        Execute the program specified by path in a new process.

        path
          Path of executable file.
        argv
          Tuple or list of strings.
        env
          Dictionary of strings mapping to strings.
        file_actions
          A sequence of file action tuples.
        setpgroup
          The pgroup to use with the POSIX_SPAWN_SETPGROUP flag.
        resetids
          If the value is `True` the POSIX_SPAWN_RESETIDS will be activated.
        setsid
          If the value is `True` the POSIX_SPAWN_SETSID or POSIX_SPAWN_SETSID_NP will be activated.
        setsigmask
          The sigmask to use with the POSIX_SPAWN_SETSIGMASK flag.
        setsigdef
          The sigmask to use with the POSIX_SPAWN_SETSIGDEF flag.
        scheduler
          A tuple with the scheduler policy (optional) and parameters.

### pread
        Read a number of bytes from a file descriptor starting at a particular offset.

        Read length bytes from file descriptor fd, starting at offset bytes from
        the beginning of the file.  The file offset remains unchanged.

### preadv
        Reads from a file descriptor into a number of mutable bytes-like objects.

        Combines the functionality of readv() and pread(). As readv(), it will
        transfer data into each buffer until it is full and then move on to the next
        buffer in the sequence to hold the rest of the data. Its fourth argument,
        specifies the file offset at which the input operation is to be performed. It
        will return the total number of bytes read (which can be less than the total
        capacity of all the objects).

        The flags argument contains a bitwise OR of zero or more of the following flags:

        - RWF_HIPRI
        - RWF_NOWAIT

        Using non-zero flags requires Linux 4.6 or newer.

### putenv
        Change or add an environment variable.

### pwrite
        Write bytes to a file descriptor starting at a particular offset.

        Write buffer to fd, starting at offset bytes from the beginning of
        the file.  Returns the number of bytes writte.  Does not change the
        current file offset.

### pwritev
        Writes the contents of bytes-like objects to a file descriptor at a given offset.

        Combines the functionality of writev() and pwrite(). All buffers must be a sequence
        of bytes-like objects. Buffers are processed in array order. Entire contents of first
        buffer is written before proceeding to second, and so on. The operating system may
        set a limit (sysconf() value SC_IOV_MAX) on the number of buffers that can be used.
        This function writes the contents of each object to the file descriptor and returns
        the total number of bytes written.

        The flags argument contains a bitwise OR of zero or more of the following flags:

        - RWF_DSYNC
        - RWF_SYNC
        - RWF_APPEND

        Using non-zero flags requires Linux 4.7 or newer.

### read
        Read from a file descriptor.  Returns a bytes object.

### readlink
        Return a string representing the path to which the symbolic link points.

        If dir_fd is not None, it should be a file descriptor open to a directory,
        and path should be relative; path will then be relative to that directory.

        dir_fd may not be implemented on your platform.  If it is unavailable,
        using it will raise a NotImplementedError.

### readv
        Read from a file descriptor fd into an iterable of buffers.

        The buffers should be mutable buffers accepting bytes.
        readv will transfer data into each buffer until it is full
        and then move on to the next buffer in the sequence to hold
        the rest of the data.

        readv returns the total number of bytes read,
        which may be less than the total capacity of all the buffers.

### register_at_fork
        Register callables to be called when forking a new process.

          before
            A callable to be called in the parent before the fork() syscall.
          after_in_child
            A callable to be called in the child after fork().
          after_in_parent
            A callable to be called in the parent after fork().

        'before' callbacks are called in reverse order.
        'after_in_child' and 'after_in_parent' callbacks are called in order.

### remove
        Remove a file (same as unlink()).

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### removexattr
        Remove extended attribute attribute on path.

        path may be either a string, a path-like object, or an open file descriptor.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, removexattr will modify the symbolic link itself instead of the file
          the link points to.

### rename
        Rename a file or directory.

        If either src_dir_fd or dst_dir_fd is not None, it should be a file
          descriptor open to a directory, and the respective path string (src or dst)
          should be relative; the path will then be relative to that directory.
        src_dir_fd and dst_dir_fd, may not be implemented on your platform.
          If they are unavailable, using them will raise a NotImplementedError.

### replace
        Rename a file or directory, overwriting the destination.

        If either src_dir_fd or dst_dir_fd is not None, it should be a file
          descriptor open to a directory, and the respective path string (src or dst)
          should be relative; the path will then be relative to that directory.
        src_dir_fd and dst_dir_fd, may not be implemented on your platform.
          If they are unavailable, using them will raise a NotImplementedError.

### rmdir
        Remove a directory.

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### scandir
        Return an iterator of DirEntry objects for given path.

        path can be specified as either str, bytes, or a path-like object.  If path
        is bytes, the names of yielded DirEntry objects will also be bytes; in
        all other circumstances they will be str.

        If path is None, uses the path='.'.

### sched_get_priority_max
        Get the maximum scheduling priority for policy.

### sched_get_priority_min
        Get the minimum scheduling priority for policy.

### sched_getaffinity
        Return the affinity of the process identified by pid (or the current process if zero).

        The affinity is returned as a set of CPU identifiers.

### sched_getparam
        Returns scheduling parameters for the process identified by pid.

        If pid is 0, returns parameters for the calling process.
        Return value is an instance of sched_param.

### sched_getscheduler
        Get the scheduling policy for the process identified by pid.

        Passing 0 for pid returns the scheduling policy for the calling process.

### sched_rr_get_interval
        Return the round-robin quantum for the process identified by pid, in seconds.

        Value returned is a float.

### sched_setaffinity
        Set the CPU affinity of the process identified by pid to mask.

        mask should be an iterable of integers identifying CPUs.

### sched_setparam
        Set scheduling parameters for the process identified by pid.

        If pid is 0, sets parameters for the calling process.
        param should be an instance of sched_param.

### sched_setscheduler
        Set the scheduling policy for the process identified by pid.

        If pid is 0, the calling process is changed.
        param is an instance of sched_param.

### sched_yield
        Voluntarily relinquish the CPU.

### sendfile
        Copy count bytes from file descriptor in_fd to file descriptor out_fd.

### set_blocking
        Set the blocking mode of the specified file descriptor.

        Set the O_NONBLOCK flag if blocking is False,
        clear the O_NONBLOCK flag otherwise.

### set_inheritable
        Set the inheritable flag of the specified file descriptor.

### setegid
        Set the current process's effective group id.

### seteuid
        Set the current process's effective user id.

### setgid
        Set the current process's group id.

### setgroups
        Set the groups of the current process to list.

### setpgid
        Call the system call setpgid(pid, pgrp).

### setpgrp
        Make the current process the leader of its process group.

### setpriority
        Set program scheduling priority.

### setregid
        Set the current process's real and effective group ids.

### setresgid
        Set the current process's real, effective, and saved group ids.

### setresuid
        Set the current process's real, effective, and saved user ids.

### setreuid
        Set the current process's real and effective user ids.

### setsid
        Call the system call setsid().

### setuid
        Set the current process's user id.

### setxattr
        Set extended attribute attribute on path to value.

        path may be either a string, a path-like object,  or an open file descriptor.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, setxattr will modify the symbolic link itself instead of the file
          the link points to.

### splice
        Transfer count bytes from one pipe to a descriptor or vice versa.

          src
            Source file descriptor.
          dst
            Destination file descriptor.
          count
            Number of bytes to copy.
          offset_src
            Starting offset in src.
          offset_dst
            Starting offset in dst.
          flags
            Flags to modify the semantics of the call.

        If offset_src is None, then src is read from the current position;
        respectively for offset_dst. The offset associated to the file
        descriptor that refers to a pipe must be None.

### stat
        Perform a stat system call on the given path.

          path
            Path to be examined; can be string, bytes, a path-like object or
            open-file-descriptor int.
          dir_fd
            If not None, it should be a file descriptor open to a directory,
            and path should be a relative string; path will then be relative to
            that directory.
          follow_symlinks
            If False, and the last element of the path is a symbolic link,
            stat will examine the symbolic link itself instead of the file
            the link points to.

        dir_fd and follow_symlinks may not be implemented
          on your platform.  If they are unavailable, using them will raise a
          NotImplementedError.

        It's an error to use dir_fd or follow_symlinks when specifying path as
          an open file descriptor.

### statvfs
        Perform a statvfs system call on the given path.

        path may always be specified as a string.
        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.

### strerror
        Translate an error code to a message string.

### symlink
        Create a symbolic link pointing to src named dst.

        target_is_directory is required on Windows if the target is to be
          interpreted as a directory.  (On Windows, symlink requires
          Windows 6.0 or greater, and raises a NotImplementedError otherwise.)
          target_is_directory is ignored on non-Windows platforms.

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### sync
        Force write of everything to disk.

### sysconf
        Return an integer-valued system configuration variable.

### system
        Execute the command in a subshell.

### tcgetpgrp
        Return the process group associated with the terminal specified by fd.

### tcsetpgrp
        Set the process group associated with the terminal specified by fd.

### times
        Return a collection containing process timing information.

        The object returned behaves like a named tuple with these fields:
          (utime, stime, cutime, cstime, elapsed_time)
        All fields are floating point numbers.

### truncate
        Truncate a file, specified by path, to a specific length.

        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.

### ttyname
        Return the name of the terminal device connected to 'fd'.

        fd
          Integer file descriptor handle.

### umask
        Set the current numeric umask and return the previous umask.

### uname
        Return an object identifying the current operating system.

        The object behaves like a named tuple with the following fields:
          (sysname, nodename, release, version, machine)

### unlink
        Remove a file (same as remove()).

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        dir_fd may not be implemented on your platform.
          If it is unavailable, using it will raise a NotImplementedError.

### unsetenv
        Delete an environment variable.

### urandom
        Return a bytes object containing random bytes suitable for cryptographic use.

### utime
        Set the access and modified time of path.

        path may always be specified as a string.
        On some platforms, path may also be specified as an open file descriptor.
          If this functionality is unavailable, using it raises an exception.

        If times is not None, it must be a tuple (atime, mtime);
            atime and mtime should be expressed as float seconds since the epoch.
        If ns is specified, it must be a tuple (atime_ns, mtime_ns);
            atime_ns and mtime_ns should be expressed as integer nanoseconds
            since the epoch.
        If times is None and ns is unspecified, utime uses the current time.
        Specifying tuples for both times and ns is an error.

        If dir_fd is not None, it should be a file descriptor open to a directory,
          and path should be relative; path will then be relative to that directory.
        If follow_symlinks is False, and the last element of the path is a symbolic
          link, utime will modify the symbolic link itself instead of the file the
          link points to.
        It is an error to use dir_fd or follow_symlinks when specifying path
          as an open file descriptor.
        dir_fd and follow_symlinks may not be available on your platform.
          If they are unavailable, using them will raise a NotImplementedError.

### wait
        Wait for completion of a child process.

        Returns a tuple of information about the child process:
            (pid, status)

### wait3
        Wait for completion of a child process.

        Returns a tuple of information about the child process:
          (pid, status, rusage)

### wait4
        Wait for completion of a specific child process.

        Returns a tuple of information about the child process:
          (pid, status, rusage)

### waitid
        Returns the result of waiting for a process or processes.

          idtype
            Must be one of be P_PID, P_PGID or P_ALL.
          id
            The id to wait on.
          options
            Constructed from the ORing of one or more of WEXITED, WSTOPPED
            or WCONTINUED and additionally may be ORed with WNOHANG or WNOWAIT.

        Returns either waitid_result or None if WNOHANG is specified and there are
        no children in a waitable state.

### waitpid
        Wait for completion of a given child process.

        Returns a tuple of information regarding the child process:
            (pid, status)

        The options argument is ignored on Windows.

### waitstatus_to_exitcode
        Convert a wait status to an exit code.

        On Unix:

        * If WIFEXITED(status) is true, return WEXITSTATUS(status).
        * If WIFSIGNALED(status) is true, return -WTERMSIG(status).
        * Otherwise, raise a ValueError.

        On Windows, return status shifted right by 8 bits.

        On Unix, if the process is being traced or if waitpid() was called with
        WUNTRACED option, the caller must first check if WIFSTOPPED(status) is true.
        This function must not be called if WIFSTOPPED(status) is true.

### write
        Write a bytes object to a file descriptor.

### writev
        Iterate over buffers, and write the contents of each to a file descriptor.

        Returns the total number of bytes written.
        buffers must be a sequence of bytes-like objects.

## DATA
    CLD_CONTINUED = 6
    CLD_DUMPED = 3
    CLD_EXITED = 1
    CLD_KILLED = 2
    CLD_STOPPED = 5
    CLD_TRAPPED = 4
    EFD_CLOEXEC = 524288
    EFD_NONBLOCK = 2048
    EFD_SEMAPHORE = 1
    EX_CANTCREAT = 73
    EX_CONFIG = 78
    EX_DATAERR = 65
    EX_IOERR = 74
    EX_NOHOST = 68
    EX_NOINPUT = 66
    EX_NOPERM = 77
    EX_NOUSER = 67
    EX_OK = 0
    EX_OSERR = 71
    EX_OSFILE = 72
    EX_PROTOCOL = 76
    EX_SOFTWARE = 70
    EX_TEMPFAIL = 75
    EX_UNAVAILABLE = 69
    EX_USAGE = 64
    F_LOCK = 1
    F_OK = 0
    F_TEST = 3
    F_TLOCK = 2
    F_ULOCK = 0
    GRND_NONBLOCK = 1
    GRND_RANDOM = 2
    MFD_ALLOW_SEALING = 2
    MFD_CLOEXEC = 1
    MFD_HUGETLB = 4
    MFD_HUGE_16GB = 2281701376
    MFD_HUGE_16MB = 1610612736
    MFD_HUGE_1GB = 2013265920
    MFD_HUGE_1MB = 1342177280
    MFD_HUGE_256MB = 1879048192
    MFD_HUGE_2GB = 2080374784
    MFD_HUGE_2MB = 1409286144
    MFD_HUGE_32MB = 1677721600
    MFD_HUGE_512KB = 1275068416
    MFD_HUGE_512MB = 1946157056
    MFD_HUGE_64KB = 1073741824
    MFD_HUGE_8MB = 1543503872
    MFD_HUGE_MASK = 63
    MFD_HUGE_SHIFT = 26
    NGROUPS_MAX = 65536
    O_ACCMODE = 3
    O_APPEND = 1024
    O_ASYNC = 8192
    O_CLOEXEC = 524288
    O_CREAT = 64
    O_DIRECT = 16384
    O_DIRECTORY = 65536
    O_DSYNC = 4096
    O_EXCL = 128
    O_FSYNC = 1052672
    O_LARGEFILE = 0
    O_NDELAY = 2048
    O_NOATIME = 262144
    O_NOCTTY = 256
    O_NOFOLLOW = 131072
    O_NONBLOCK = 2048
    O_PATH = 2097152
    O_RDONLY = 0
    O_RDWR = 2
    O_RSYNC = 1052672
    O_SYNC = 1052672
    O_TMPFILE = 4259840
    O_TRUNC = 512
    O_WRONLY = 1
    POSIX_FADV_DONTNEED = 4
    POSIX_FADV_NOREUSE = 5
    POSIX_FADV_NORMAL = 0
    POSIX_FADV_RANDOM = 1
    POSIX_FADV_SEQUENTIAL = 2
    POSIX_FADV_WILLNEED = 3
    POSIX_SPAWN_CLOSE = 1
    POSIX_SPAWN_DUP2 = 2
    POSIX_SPAWN_OPEN = 0
    PRIO_PGRP = 1
    PRIO_PROCESS = 0
    PRIO_USER = 2
    P_ALL = 0
    P_PGID = 2
    P_PID = 1
    P_PIDFD = 3
    RTLD_DEEPBIND = 8
    RTLD_GLOBAL = 256
    RTLD_LAZY = 1
    RTLD_LOCAL = 0
    RTLD_NODELETE = 4096
    RTLD_NOLOAD = 4
    RTLD_NOW = 2
    RWF_APPEND = 16
    RWF_DSYNC = 2
    RWF_HIPRI = 1
    RWF_NOWAIT = 8
    RWF_SYNC = 4
    R_OK = 4
    SCHED_BATCH = 3
    SCHED_FIFO = 1
    SCHED_IDLE = 5
    SCHED_OTHER = 0
    SCHED_RESET_ON_FORK = 1073741824
    SCHED_RR = 2
    SEEK_DATA = 3
    SEEK_HOLE = 4
    SPLICE_F_MORE = 4
    SPLICE_F_MOVE = 1
    SPLICE_F_NONBLOCK = 2
    ST_APPEND = 256
    ST_MANDLOCK = 64
    ST_NOATIME = 1024
    ST_NODEV = 4
    ST_NODIRATIME = 2048
    ST_NOEXEC = 8
    ST_NOSUID = 2
    ST_RDONLY = 1
    ST_RELATIME = 4096
    ST_SYNCHRONOUS = 16
    ST_WRITE = 128
    TMP_MAX = 238328
    WCONTINUED = 8
    WEXITED = 4
    WNOHANG = 1
    WNOWAIT = 16777216
    WSTOPPED = 2
    WUNTRACED = 2
    W_OK = 2
    XATTR_CREATE = 1
    XATTR_REPLACE = 2
    XATTR_SIZE_MAX = 65536
    X_OK = 1
    confstr_names = {'CS_GNU_LIBC_VERSION': 2, 'CS_GNU_LIBPTHREAD_VERSION'...
    environ = {b'LC_CTYPE': b'C.UTF-8', b'PATH': b'/usr/local/bin:/usr/bin...
    pathconf_names = {'PC_ALLOC_SIZE_MIN': 18, 'PC_ASYNC_IO': 10, 'PC_CHOW...
    sysconf_names = {'SC_2_CHAR_TERM': 95, 'SC_2_C_BIND': 47, 'SC_2_C_DEV'...

## FILE
    (built-in)