# check /tmp/ss.log greater than 1M,empty ss.log
# 1 kB = 1000 (103) byte
# 1 MB = 1 000 000 (106) byte
# 1 GB = 1 000 000 000 (109) byte
# 1 TB = 1 000 000 000 000 (1012) bytefile="/tmp/ss.log"
if
[ $(wc $file | awk '{print $3}') -gt 1024000 ];
then
cat /dev/null > $file
fi