shell script that notes timestamps and runs a command every 15min and sends the result to a .txt -

doin experiment on tor , messuring performance of network. need script notes timestamps , runs command "proxychains iperf3 -c "ip address" , send result .txt . need run every 15min 24/7. it´s getting annoying stay awake. thansk !

you can start following:

touch mylogfile.txt while true     proxychains iperf3 -c "ip address"  >> mylogfile.txt     sleep 900 done 

if want run without crontab