You can find the command: Assign Net/Port Property to extract the port information by label if you don't have any port property on Laker database.

You can find this command in menu: Library from Laker main window or menu: Cell from layout window.
Before you access this command, please take a look of your tech file definition: tfAbstractCell

tfAbstractCell {
   #------------------------------------------------------------------
   # define cell pin extraction rule
   #------------------------------------------------------------------
   #mapText2Pin { {txexLayerName} {ExtractedLayer1 ...} $ExtractAll {OutputLayer} }
   mapText2Pin { {POLYtext drawing }   { POLY drawing} }
   mapText2Pin { {MT1text  drawing }   MT1 }
...
}

If you already have the port infortmation on a cell, you can use the following Tcl script to dump out the ASCII list of the port by the giving cell name and library name.

#  File: dumpPortInfo.tcl
#
#  Load this script by the command:  source  dumpPortInfo.tcl from Laker main window
#  Run this script by the command: dumpPort  <libName>  <cellName>
#
proc dumpPort {libName cellName {viewName layout}} {
 dbOpenLib -lib $libName -mode readOnly
 set cv [dbOpenCV -lib $libName -cell $cellName -view $viewName -mode readOnly]
 if {[dbIsDbObj -obj $cv] != 1} {
   lakerMessage "Can't find cell: $cellName from library: $libName"
 }
 set Ports [dbGet -obj $cv -attr Ports]
 lakerMessage "Report Port List...  \nCell: $cellName from library: $libName"
 puts "Report Port List...  \ncell: $cellName from library: $libName"
 foreach port $Ports {
   set Name [dbGet -obj $port -attr Name]
   set Dir [dbGet -obj $port -attr Dir]
   lakerMessage "  Port: $Name  Direction: $Dir"
   puts "  Port: $Name\tDirection: $Dir"
 }
 puts "\n"
 dbCloseCV -cv $cv

 dbCloseLib -lib $libName
}