Attachment 2856 Details for Bug 6514 – Work around solution to suppress pynotify warning messages

Work around solution to suppress pynotify warning messages

suproutp.py (text/x-python), 1.67 KB, created by R Topics on 2012-09-25 16:02:44 CEST

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Creator: R Topics

Created: 2012-09-25 16:02:44 CEST

Size: 1.67 KB

patch

obsolete

>import os
>from contextlib import contextmanager
>
>@contextmanager
>def suppress_output(fd):
>    """
>    Suppress output to the given ``fd``::
>
>       with suppress_output(sys.stderr):
>           # in this block any output to standard error is suppressed
>
>    ``fd`` is an integral file descriptor, or any object with a ``fileno()``
>    method.
>    """
>    if hasattr(fd, 'fileno'):
>        # we were given a file-like object with an underlying fd
>        if hasattr(fd, 'flush'):
>            # flush Python-side buffers before redirecting
>            fd.flush()
>        # get the fd to redirect
>        fd = fd.fileno()
>
>    # duplicate the file descriptor to restore it eventually
>    oldfd = os.dup(fd)
>    try:
>        # open the trash can
>        devnull = os.open(os.devnull, os.O_WRONLY)
>        try:
>            # point the file descriptor to the trash can
>            os.dup2(devnull, fd)
>        finally:
>            # close the old trash can descriptor, we don't need it anymore
>            # since the fd now points to the trash can
>            os.close(devnull)
>        # enter the callers block
>        yield
>        # restore the file descriptor
>        os.dup2(oldfd, fd)
>    finally:
>        # close the duplicated copy of the original fd, we don't need it
>        # anymore now that fd is restored
>        os.close(oldfd)
>
>if __name__ == "__main__":
>
>    import sys
>    import warnings
>
>    print "\nSupress output, no warnings should display on importing pynotify"
>    print " "
>
>    with suppress_output(sys.stderr):
>        import pynotify
>
>    # generate a warning to show output has been restored
>    def fxn():
>        warnings.warn("Warnings have been restored", Warning)
>
>    fxn()
>

import os
from contextlib import contextmanager

@contextmanager
def suppress_output(fd):
    """
    Suppress output to the given ``fd``::

       with suppress_output(sys.stderr):
           # in this block any output to standard error is suppressed

    ``fd`` is an integral file descriptor, or any object with a ``fileno()``
    method.
    """
    if hasattr(fd, 'fileno'):
        # we were given a file-like object with an underlying fd
        if hasattr(fd, 'flush'):
            # flush Python-side buffers before redirecting
            fd.flush()
        # get the fd to redirect
        fd = fd.fileno()

    # duplicate the file descriptor to restore it eventually
    oldfd = os.dup(fd)
    try:
        # open the trash can
        devnull = os.open(os.devnull, os.O_WRONLY)
        try:
            # point the file descriptor to the trash can
            os.dup2(devnull, fd)
        finally:
            # close the old trash can descriptor, we don't need it anymore
            # since the fd now points to the trash can
            os.close(devnull)
        # enter the callers block
        yield
        # restore the file descriptor
        os.dup2(oldfd, fd)
    finally:
        # close the duplicated copy of the original fd, we don't need it
        # anymore now that fd is restored
        os.close(oldfd)

if __name__ == "__main__":

    import sys
    import warnings

    print "\nSupress output, no warnings should display on importing pynotify"
    print " "

    with suppress_output(sys.stderr):
        import pynotify

    # generate a warning to show output has been restored
    def fxn():
        warnings.warn("Warnings have been restored", Warning)

    fxn()

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Attachments on bug 6514: 2856