_osx_support.py 文件源码

def _read_output(commandstring):
    """Output from successful command execution or None"""
    # Similar to os.popen(commandstring, "r").read(),
    # but without actually using os.popen because that
    # function is not usable during python bootstrap.
    # tempfile is also not available then.
    import contextlib
    try:
        import tempfile
        fp = tempfile.NamedTemporaryFile()
    except ImportError:
        fp = open("/tmp/_osx_support.%s"%(
            os.getpid(),), "w+b")

    with contextlib.closing(fp) as fp:
        cmd = "%s 2>/dev/null >'%s'" % (commandstring, fp.name)
        return fp.read().strip() if not os.system(cmd) else None