Port specs

Wherever portcheck takes ports (check, free, kill, list --port, scan -p), you can write:

Form	Example	Meaning
single port	80	port 80
list	22,80,443	each port
range	8000-8100	inclusive range
preset	common	a named set (below)
mixed	common,9000-9010	any combination

Whitespace around elements is ignored. Overlapping and adjacent entries are merged, so every port is used once. Commands that accept several arguments, such as portcheck check 80 443, join them with commas.

Ports must be between 1 and 65535; 0, reversed ranges like 100-10, and empty elements like 80,,443 are rejected with a clear error.

Presets

Preset names are case-insensitive.

Preset	Ports
common	45 ports developers commonly use: ssh, http(s), databases (5432, 3306, 27017, 6379, …), message brokers, dev servers (3000, 4200, 5173, 8000, 8080, …)
well-known	1-1023
registered	1024-49151
dynamic	49152-65535 (the IANA ephemeral range)
all	1-65535

Note

portcheck does not ship "top N ports" lists derived from other scanners, because they come with incompatible licenses. common is maintained by hand in pkg/portspec/presets.go. Pull requests are welcome.