I'm using MySQL, any idea where I should report the problem to?
(I'm a biologist not a computer programmer, apologies for my
ignorance)
thanks
Damian
On 28 Jul 2010, at 19:22, Martin J. Evans wrote:
Damian Keefe wrote:
Hi Folks
$DBI::VERSION = "1.609"
perl, v5.8.8 built for x86_64-linux-thread-multi
SHELL=/bin/tcsh
I'm not sure if this should be considered a bug in DBI or
elsewhere, but it has unpleasant consequences. Somewhere in the
bowels of DBI, SIGPIPE gets set to 'IGNORE'. It remains in this
state after disconnect(). If you then launch a second script
using backticks and this script contains a line like
my $first_line = `grep -v '#' $filename|head -n 1`; # to get the
first non-comment line
the shell which is invoked inherits the SIGPIPE = 'IGNORE' state.
This causes a
grep: writing output: Broken pipe
error as the grep tries to write to the head process which has
exited.
It took me a while to work this out because of the way perl
populates the %SIG hash. It appears it only populates it once
from the system when it is first used in the script. If you run
the script below with the first print statement commented out you
get
connected to dk_funcgen_classify_59_MEF
SIGPIPE=IGNORE
If you uncomment the first print statement you get
SIGPIPE=UNDEF
connected to dk_funcgen_classify_59_MEF
SIGPIPE=UNDEF
However, behind the scenes, something has changed SIGPIPE to
IGNORE and the %SIG hash has not been updated.
(my workaround is to explicitly reset SIGPIPE to 'DEFAULT' in the
second script)
cheers
Damian
I suspect you'll find its your driver library that ignores SIGPIPE
as AFAIK, DBI does not.
Oracle's OCI library changes some signal dispositions for sure and
sometimes SIGPIPE/SIGCHLD.
Martin
<snipped example code>
