bash - Replace specific command line automatically and save the results

Question

I would like to get range port scan results from one of my server IP by using a single port scan command line. (Don't recommend me other port scanners like nmap which has a port range scan feature please :( )

Command-line examples are following (I just want to scan a specific IP with multiple ports)

root@localhost: serverstats IP:Port

root@localhost: serverstats 1.1.1.1:2000
Result/output↓↓↓
root@localhost:  {"online": true}

What I would like to do

root@localhost: serverstats 1.1.1.1:2200　　?    serverstats 1.1.1.1:2500  (About 300 ports)

Command result/output -> root@localhost: {"online": true}

Scan 300 port range on a single IP with the above single port scan command and save the command results/outputs automatically in a text file like the following :)

300ports.log ↓

{"online": true}
{"online": false}
{"online": false}
{"online": true}
{"online": false}
..... (and remaining 295 port scan results)

Thank you!

question from:https://stackoverflow.com/questions/65915030/replace-specific-command-line-automatically-and-save-the-results

Answer 1

IP="1.1.1.1"
for (( i=1;i<=300;i++ ));
do 
   serverstats "$IP:$i"
done | grep -E '{"online": (false|true)}' > 300ports.log

Loop 300 times to generate port numbers and use these to generate the serverstats commands. Pipe the output to grep to search for the output along with "false" or "true" and redirect the grepped output to 300port.log