You show us that data exists in the files /opt/usedports and /opt/lastports and then you show us a script that reads from /opt/ports/usedports and /opt/ports/lastports. Shouldn't your script be reading from files that exist and have data in them?

Despite what you said, ports below 1024 are called privileged ports and should not be used for "general purpose" transactions. If you are looking for a temporary (or ephemeral) port, you should use higher numbered ports. Jim's code doesn't attempt to use ports outside of the range 8193 through 32766.

Try changing the 2nd line in Jim's suggested script from:

Code:

ss | awk ' /\*/ {print $6 } > portlist.txt

to:

Code:

ss | awk ' /\*/ {print $6 }' > portlist.txt

Jim's code assumes that /bin/sh on your system is a shell that understands the syntax:

Code:

for (( var=initial_val; var < test_value; var++ ))

which might or might not be true. As you have been told before, you are likely to get suggestions that won't work on your system if you don't tell us that operating system and shell you're using!