Platform support

portly ships pre-built wheels for Linux, macOS, and Windows (multiple architectures per OS). The process lookups are implemented natively per platform — no subprocesses (lsof, netstat, tasklist, wmic, …) are spawned.

Platform	Socket lookup	Process mapping	Notes
Linux	/proc/net/{tcp,tcp6,udp,udp6}	/proc/<pid>/fd scan via procfs	Relies on procfs; works in minimal containers
macOS	libproc (proc_pidinfo)	libproc
Windows	GetExtended{Tcp,Udp}Table	ToolHelp32 snapshots via windows-sys

Permission caveats

• Visibility — process info and kills only cover processes visible to your user. Other users' listeners may report as "free"/unreachable without elevated privileges (same limitation as lsof).
• kill — sends SIGTERM unless force=True (SIGKILL). On Windows the process is always terminated forcefully. Killing another user's process requires elevated privileges and raises PermissionError (or PortlyPermissionError) otherwise.

Behavior notes

• get_info — cmd is the full command line on Linux, the executable path on macOS, and the executable name on Windows.
• find_free — the returned port can be taken between the check and your bind() (TOCTOU). If you need a race-free reservation, bind to port 0 and let the OS choose.

FreeBSD

FreeBSD support is tracked in the roadmap issue; today the package requires one of the three platforms above.