ref: 4eb4620b762356413a8c16abfa2cea1f89a3eeec
dir: /sys/src/libsec/port/reduce/
O=$1 shift objtype=$1 shift if(ls -p ../$objtype/*.[cs] >[2]/dev/null | sed 's/..$//;s/^/^/' > /tmp/reduce.$pid) { echo $* | tr ' ' \012 | grep -v -f /tmp/reduce.$pid | tr \012 ' ' } if not { # if empty directory, just return the input files echo $* } rm /tmp/reduce.$pid