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Problem redirecting stderr to pipe in subprocess
- From: Ken Brown <kbrown at cornell dot edu>
- To: cygwin <cygwin at cygwin dot com>
- Date: Sat, 08 Oct 2011 11:35:45 -0400
- Subject: Problem redirecting stderr to pipe in subprocess
The attached STC arose from my attempt to understand the problem
discussed starting in
I'm starting a new thread because there appears to be a Cygwin problem
having nothing to do with emacs.
The STC creates a pipe and then runs `bash -ic ls' in a subprocess, with
both stdout and stderr sent to the pipe. The parent process reads from
the pipe and echoes it to the terminal.
On Linux, I first get the error messages (presumably expected)
bash: cannot set terminal process group (-1): Invalid argument
bash: no job control in this shell
followed by the directory listing. On Cygwin, the bash process produces
no output but is simply stopped, and I have to kill it from another
terminal before the main program will exit. This happens both with
cygwin-1.7.9 and the latest snapshot. Here are a few comments:
1. The problem disappears if I don't send bash's stderr to the pipe.
2. The problem also disappears if I replace -ic by -c in the call to
bash, presumably because there's nothing sent to stderr in that case.
3. The problem disappears if I don't use a pipe but just have the bash
subprocess write to the terminal, even if I redirect bash's stderr to
Description: Text document
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