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From:	Herb Maeder <maeder-cygml AT maeder DOT org>
Subject:	cygcheck output sometimes gets truncated when piped (cygwin-1.7)
Date:	Sun, 05 Oct 2008 06:36:32 -0700
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On a fresh install of cygwin-1.7 (1.7.0-30) on Vista, the output of
"cygcheck -s" sometimes gets truncated.  This seems to be more reproducible
when the output is piped to another command.

I find that this sequence is shows problem quite regularly (typically more
than half of the cycheck commands will have the output truncated):

    i=0; while [ $i -lt 10 ] ; do echo $i; cygcheck -s | grep . > out.$i ;
i=$(($i + 1)); done ; ls -l out.*

There seems to be two failure modes.  The first truncates the ouptut
within the firt three lines.  The second hangs the "cygcheck -s | grep ."
command so that it will not respond to job control (interrupt or suspend).
In this case I need to kill the grep from another shell to complete the
loop.

Here is some sample output from the above command:

    0
    1
    2
    3
    4
    5
    6
    7
    8
    9
    -rw-r--r-- 1 herb Domain Users 7440 Oct  5 05:39 out.0
    -rw-r--r-- 1 herb Domain Users  151 Oct  5 05:39 out.1
    -rw-r--r-- 1 herb Domain Users   36 Oct  5 05:39 out.2
    -rw-r--r-- 1 herb Domain Users 7440 Oct  5 05:39 out.3
    -rw-r--r-- 1 herb Domain Users  151 Oct  5 05:39 out.4
    -rw-r--r-- 1 herb Domain Users  151 Oct  5 05:39 out.5
    -rw-r--r-- 1 herb Domain Users 7440 Oct  5 05:39 out.6
    -rw-r--r-- 1 herb Domain Users  151 Oct  5 05:39 out.7
    -rw-r--r-- 1 herb Domain Users    0 Oct  5 05:39 out.8
    -rw-r--r-- 1 herb Domain Users  151 Oct  5 05:39 out.9

Files of size 7440 have the normal expected output, the one with 0 length
hung (needed to kill the grep), and the rest had the output truncated
within the first three lines.

Piping into "cat" instead of "grep ." can also show the problem, but far
less frequently (maybe 3 out of 500 times).  I have also seen the problem
by simply redirecting the output of "cygcheck -s" into a file and even on
the command line with no piping or redirecting.  But those are far less
reproducible.

I'm hoping that the problem can be easily reproduced by others.  But if
not, please let me know what I can do to collect more information.

Herb.

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