Appending output of a command to the same file as the one that command
is reading from is a dangerous practice. It seems to have accidentally
worked with all the awk implementations we have tested against so far,
but for BusyBox awk, doing this may result in the input/output file
being written to in an infinite loop. Prevent this from happening by
redirect awk output to a temporary file and appending its contents to
the original file in a separate shell pipeline.
$1 = "H9P7U7TR2U91D0V0LJS9L1GIDNP90U3H." ZONE;
$9 = "H9P7U7TR2U91D0V0LJS9L1GIDNP90U3I";
print;
-}' ${file} >> ${file}
+}' ${file} > ${file}.tmp
+cat ${file}.tmp >> ${file}
+rm -f ${file}.tmp
$SIGNER -3 - -Px -Z nonsecify -O full -o ${zone} -f ${file} ${file} $zsk > s.out$n 2>&1 || dumpit s.out$n