Class Win32ShellCommandController

IPython/utils/_process_win32_controller.py:190–544

Runs a shell command in a 'with' context. This implementation is Win32-specific. Example: # Runs the command interactively with default console stdin/stdout with ShellCommandController('python -i') as scc: scc.run() # Runs the command using the provided

class Win32ShellCommandController:
    """Runs a shell command in a 'with' context.

    This implementation is Win32-specific.

    Example:
        # Runs the command interactively with default console stdin/stdout
        with ShellCommandController('python -i') as scc:
            scc.run()

        # Runs the command using the provided functions for stdin/stdout
        def my_stdout_func(s):
            # print or save the string 's'
            write_to_stdout(s)
        def my_stdin_func():
            # If input is available, return it as a string.
            if input_available():
                return get_input()
            # If no input available, return None after a short delay to
            # keep from blocking.
            else:
                time.sleep(0.01)
                return None
      
        with ShellCommandController('python -i') as scc:
            scc.run(my_stdout_func, my_stdin_func)
    """

    def __init__(self, cmd, mergeout = True):
        """Initializes the shell command controller.

        The cmd is the program to execute, and mergeout is
        whether to blend stdout and stderr into one output
        in stdout. Merging them together in this fashion more
        reliably keeps stdout and stderr in the correct order
        especially for interactive shell usage.
        """
        self.cmd = cmd
        self.mergeout = mergeout

    def __enter__(self):
        cmd = self.cmd
        mergeout = self.mergeout

        self.hstdout, self.hstdin, self.hstderr = None, None, None
        self.piProcInfo = None
        try:
            p_hstdout, c_hstdout, p_hstderr, \
                    c_hstderr, p_hstdin, c_hstdin = [None]*6

            # SECURITY_ATTRIBUTES with inherit handle set to True
            saAttr = SECURITY_ATTRIBUTES()
            saAttr.nLength = ctypes.sizeof(saAttr)
            saAttr.bInheritHandle = True
            saAttr.lpSecurityDescriptor = None

            def create_pipe(uninherit):
                """Creates a Windows pipe, which consists of two handles.