En Thu, 28 Feb 2008 14:29:04 -0200, Ian Clark <[EMAIL PROTECTED]>
escribió:
> On 2008-02-27, Gabriel Genellina <[EMAIL PROTECTED]> wrote:
>> En Wed, 27 Feb 2008 15:06:36 -0200, Ian Clark <[EMAIL PROTECTED]>
>> escribi�:
>>
>>> On 2008-02-27, Michael Goerz <[EMAIL PROTECTED]> wrote:
>>>> Hi,
>>>>
>>>> I would like to raise an exception any time a subprocess tries to read
>>>> from STDIN:
>>>>
>>>> latexprocess = subprocess.Popen( \
>>>> 'pdflatex' + " " \
>>>> + 'test' + " 2>&1", \
>>>> shell=True, \
>>>> cwd=os.getcwd(), \
>>>> env=os.environ, \
>>>> stdin=StdinCatcher() # any ideas here?
>>>> )
>>>>
>>>> An exception should be raised whenever the pdflatex process
>>>> reads from STDIN... and I have no idea how to do it. Any suggestions?
>>
>>> How about with a file-like object? I haven't tested this with
>>> subprocess
>>> so you might want to read the manual on files if it doesn't work[1].
>>
>> Won't work for an external process, as pdflatex (and the OS) knows
>> nothing
>> about Python objects. The arguments to subprocess.Popen must be actual
>> files having real OS file descriptors.
>
> Taken from the subprocess documentation (emphasis mine). [1]
>
> stdin, stdout and stderr specify the executed programs' standard
> input, standard output and standard error file handles,
> respectively. Valid values are PIPE, an existing file descriptor (a
> positive integer), *an existing file object*, and None.
>
> The following peice of code works fine for me with the subprocess
> module. NOTE: the only difference from this and the last I posted is
> that I set fileno() to _error().
>
> import sys
> import subprocess
>
> class ErrorFile(object):
> def _error(self, *args, **kwargs):
> raise AssertionError("Illegal Access")
>
> def _noop(self, *args, **kwargs):
> pass
>
> close = flush = seek = tell = _noop
> next = read = readline = readlines = xreadlines = tuncate =
> _error
> truncate = write = writelines = fileno = _error
> # ^^^^^^
>
> proc = subprocess.Popen("cat -", shell=True, stdin=ErrorFile())
> ret = proc.wait()
> print "return", ret
I don't see how this could ever work. The shell knows nothing about your
ErrorFile objects. If subprocess.Popen doesn't reject that ErrorFile
instance, it's a bug. An ErrorFile instance is not "an existing file
object".
--
Gabriel Genellina
--
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