Plan 9 from Bell Labs’s /usr/web/sources/contrib/gabidiaz/root/sys/src/cmd/snmpfs/tools/avg.rc
#!/bin/rc awk -v 'nf='^$1 'BEGIN{n=1;} { gsub(/\(/,//,$nf); gsub(/\)/,//,$nf); last=now; now=$nf if ( last < now && last > 0 ) { printf("%d\n",now-last); } }'