ref: 116ca59949171f0aed9092157f3c89ddae2e36e7
dir: /sys/src/libsec/port/reduce/
O=$1
shift
objtype=$1
shift
ls -p ../$objtype/*.[cs] >[2]/dev/null | sed 's/..$//' > /tmp/reduce.$pid
#
# if empty directory, just return the input files
#
if (! ~ $status '|') {
echo $*
rm /tmp/reduce.$pid
exit 0
}
echo $* | tr ' ' \012 | grep -v -f /tmp/reduce.$pid | tr \012 ' '
rm /tmp/reduce.$pid