
[;1m  port_info(Port)[0m

  Returns a list containing tuples with information about [;;4mPort[0m, or [;;4m[0m
  [;;4mundefined[0m if the port is not open.

  The order of the tuples is undefined, and all the tuples are not
  mandatory. If the port is closed and the calling process was
  previously linked to the port, the exit signal from the port is
  guaranteed to be delivered before [;;4mport_info/1[0m returns [;;4mundefined[0m.

  The result contains information about the following [;;4mItem[0ms:

   • [;;4mregistered_name[0m (if the port has a registered name)

   • [;;4mid[0m

   • [;;4mconnected[0m

   • [;;4mlinks[0m

   • [;;4mname[0m

   • [;;4minput[0m

   • [;;4moutput[0m

  For more information about the different [;;4mItem[0ms, see [;;4mport_info/2[0m.

  Failure: [;;4mbadarg[0m if [;;4mPort[0m is not a local port identifier, or an
  atom.

[;1m  port_info(Port, Item)[0m

  Returns information about [;;4mPort[0m.

  If the port identified by [;;4mPort[0m is not open, [;;4mundefined[0m is
  returned. If the port is closed and the calling process was
  previously linked to the port, the exit signal from the port is
  guaranteed to be delivered before [;;4mport_info/2[0m returns [;;4mundefined[0m.

  [;;4mItem[0m is one of the following and can be used to get various
  information about the [;;4mPort[0m.

   • [;;4mconnected[0m - returns [;;4m{connected, Pid}[0m where [;;4mPid[0m is the
     process identifier of the process connected to the port.

   • [;;4mid[0m - returns [;;4m{id, Index}[0m where [;;4mIndex[0m is the internal
     index of the port. This index can be used to separate ports.

   • [;;4minput[0m - returns [;;4m{input, Bytes}[0m where [;;4mBytes[0m is the total
     number of bytes read from the port.

   • [;;4mlinks[0m - returns [;;4m{links, Pids}[0m where [;;4mPids[0m is a list of
     the process identifiers of the processes that the port is
     linked to.

   • [;;4mlocking[0m - returns [;;4m{locking, Locking}[0m where [;;4mLocking[0m is
     one of the following:

      ￮ [;;4mport_level[0m (port-specific locking)

      ￮ [;;4mdriver_level[0m (driver-specific locking) Notice that
        these results are highly implementation-specific and
        can change in a future release.

     Since: OTP R16B

   • [;;4mmemory[0m - returns [;;4m{memory, Bytes}[0m where [;;4mBytes[0m is the
     total number of bytes allocated for this port by the runtime
     system. The port itself can have allocated memory that is
     not included in [;;4mBytes[0m.

     Since: OTP R16B

   • [;;4mmonitors[0m - returns [;;4m{monitors, Monitors}[0m where [;;4mMonitors[0m
     represent processes monitored by this port.

     Since: OTP R16B

   • [;;4mmonitored_by[0m - returns [;;4m{monitored_by, MonitoredBy}[0m where [;;4m[0m
     [;;4mMonitoredBy[0m is a list of pids that are monitoring given
     port at the moment.

     Since: OTP 19.0

   • [;;4mname[0m - returns [;;4m{name, Name}[0m where [;;4mName[0m is the command
     name set by [;;4mopen_port/2[0m.

   • [;;4mos_pid[0m - returns [;;4m{os_pid, OsPid}[0m where [;;4mOsPid[0m is the
     process identifier (or equivalent) of an OS process created
     with [;;4mopen_port({spawn | spawn_executable, Command},[0m
     [;;4mOptions)[0m. If the port is not the result of spawning an OS
     process, the value is [;;4mundefined[0m.

     Since: OTP R16B

   • [;;4moutput[0m - returns [;;4m{output, Bytes}[0m where [;;4mBytes[0m is the
     total number of bytes written to the port from Erlang
     processes using [;;4mport_command/2[0m, [;;4mport_command/3[0m, or [;;4mPort ![0m
     [;;4m{Owner, {command, Data}[0m.

   • [;;4mparallelism[0m - returns [;;4m{parallelism, Boolean}[0m where [;;4m[0m
     [;;4mBoolean[0m corresponds to the port parallelism hint used by
     this port. For more information, see option [;;4mparallelism[0m of [;;4m[0m
     [;;4mopen_port/2[0m.

     Since: OTP R16B

   • [;;4mqueue_size[0m - returns [;;4m{queue_size, Bytes}[0m where [;;4mBytes[0m is
     the total number of bytes queued by the port using the ERTS
     driver queue implementation.

     Since: OTP R16B

   • [;;4mregistered_name[0m - returns [;;4m{registered_name,[0m
     [;;4mRegisteredName}[0m where [;;4mRegisteredName[0m is the registered
     name of the port. If the port has no registered name, [;;4m[][0m
     is returned.

  Failure: [;;4mbadarg[0m if [;;4mPort[0m is not a local port identifier, or an
  atom.
