Gentlemen, I am disturbed by these seemingly irregular results,
# perl -pwle 's/\d{4}/0000/' mm|sort|uniq -c
88 ++ kill 0000
44 ++ set +m
44 ++ set -m
1 ++ sleep 33
2 ++ sleep 66
1 ./rt: line 12: 0000 Terminated sleep 33
1 ./rt: line 12: 0000 Terminated sleep 44
1 ./rt: line 13: 0000 Terminated sleep 33
1 ./rt: line 13: 0000 Terminated sleep 44
1 ./rt: line 13: 0000 Terminated sleep 55
3 ./rt: line 14: 0000 Terminated sleep 33
3 ./rt: line 14: 0000 Terminated sleep 44
3 ./rt: line 14: 0000 Terminated sleep 55
from running my program
# cat rt
set -x
set -m
sleep 33&
kill $!
set +m
sleep 44&
kill $!
sleep 55&
set -m
kill $!
sleep 66&
set +m
kill $!
# for i in `seq 22`; do ./rt; done 2> mm
We see some of the sleeps are reported some of the time, and on what
line something was terminated differs too. Also didn't I run it 22
times? Why do some things show up only a couple times instead of all or
none?
P.S., on the man page
-m Monitor mode. Job control is enabled. This option is on
by default for interactive shells on systems that
support it (see JOB CONTROL above). Background
processes run in a separate process group and a
line containing their exit status is printed upon
their completion.
Perhaps mention if what happens if this is turned on or off after
starting the job but before its completion.
