systemctl-list-sockets

List socket-activated units

TLDR

List active socket units

$ systemctl list-sockets

Show socket types

$ systemctl list-sockets --show-types

List all including inactive

$ systemctl list-sockets -a

Filter by state

$ systemctl list-sockets --state [active|inactive|failed]

Filter by pattern

$ systemctl list-sockets [pattern]

SYNOPSIS

systemctl list-sockets [OPTIONS] [PATTERN...]

systemctl list-sockets displays socket units currently active in memory, ordered by listening address. Socket units implement socket activation, where services are started on-demand when connections arrive.The output shows the listening address (IP:port, path, etc.), the socket unit name, and the unit it activates.

PARAMETERS

-a, --all

Include inactive and failed socket units

--state= STATE

Filter by state

--show-types

Display socket types (Stream, Datagram, etc.)

--no-legend

Suppress header and footer

--no-pager

Disable pager

CAVEATS

Shows systemd-managed sockets only, not all listening sockets on the system. Use `ss` or `netstat` for a complete list. Socket activation may cause startup delays on first connection.

HISTORY

The list-sockets subcommand provides insight into systemd's socket activation infrastructure, which reduces memory usage by starting services only when needed.