Method get_target_extruder_from_command

Marlin/src/gcode/gcode.cpp:124–136

* Get the target extruder from the T parameter or the active_extruder * Return -1 if the T parameter is out of range */

 * Return -1 if the T parameter is out of range
 */
int8_t GcodeSuite::get_target_extruder_from_command() {
  #if HAS_TOOLCHANGE
    if (parser.seenval('T')) {
      const int8_t e = parser.value_byte();
      if (e < EXTRUDERS) return e;
      SERIAL_ECHO_START();
      SERIAL_CHAR('M'); SERIAL_ECHO(parser.codenum);
      SERIAL_ECHOLNPGM(" " STR_INVALID_EXTRUDER " ", e);
      return -1;
    }
  #endif
  return active_extruder;
}

/**
 * Get the target E stepper from the 'T' parameter.