On 27/08/2014 at 08:38,
Ole Tange <o...@tange.dk> wrote:
> 'cat' is not atomic, so you will be inviting a race condition, where
> the 'cat' runs exactly when GNU Parallel reads the file. 'mv' is
> atomic - use that instead.
Hi,
You're right, I was afraid of some unintended side-effect like that. I'll
think about the daemon thing. For now, this is the updated script:
cp original.slf updated.slf
while [ 1 ] ; do
nice parallel --timeout 1000% --nonall -j0 -k --slf original.slf --tag
echo | \
sed -e 's/\t$//' -e '/\t/d' > tmp.slf
if ! cmp -s tmp.slf updated.slf; then
mv tmp.slf updated.slf
fi
sleep 10
done &
parallel --slf updated.slf ...
And below a version that also preserves the server options if any (the full
server entry), such as '8/server.net':
cp original.slf updated.slf
while [ 1 ] ; do
nice parallel --timeout 1000% --nonall -j0 -k --slf original.slf --tag
echo | \
sed -e 's/\t$//' -e '/\t/d' | \
nice parallel -k grep -m 1 -F {} original.slf > tmp.slf
if ! cmp -s tmp.slf updated.slf; then
mv tmp.slf updated.slf
fi
sleep 10
done &
parallel --slf updated.slf ...
--
Douglas A. Augusto
