This is pretty hard to do that on USB printer connected to windows. You have to have bidirectional driver for your printer and somehow read it (there is no that option in win32 printing). There is no bidirectional windows drivers for most of printers.

It is much easier to ReadBack from printer connected to network. You can do that with simple app called PCL Paraphernalia
http://www.pclparaphernalia.eu/index.html

ReadBack from USB printer on Linux is possible! Printer is installed as a character device (you can read and write to it).

Some tips:

• After read printer send to them ESCAPE character. If not, next send and work will not work.

  echo -e "\e" > /dev/usb/lp0

  echo -e "\e" > /dev/usb/lp0

• My printer does not respond nothing for @PJL INQUIRE *_* – no respond from printer for variables with underscore example: @PJL INQUIRE TOTALPAGE_LMT (probably total page limit) and others:
  ONLYFOR_PANEL
TOTALPAGE_LMT
COUNTPAGEPF1_LMT
COUNTPAGEPFM_LMT
A4PAGES_LMT
LEGALPAGES_LMT
JISB5PAGES_LMT
A5PAGES_LMT
A6PAGES_LMT
MONARCPAGES_LMT
PLAINPAGES_LMT
THICKPAGES_LMT
ENVELOPESPAGES_LMT
POSTCARDPAGES_LMT
LABELPAGES_LMT
• You can try to check device is busy but it not work correctly. You should do the command in loop until you read more than zero length reponse (or set timeout in looop to next try)

  while true do fuser -s /dev/usb/lp0 if [ $? -ne 0 ] then break fi done

  while true do fuser -s /dev/usb/lp0 if [ $? -ne 0 ] then break fidone

• Send PJL:

  echo -e "\e%-12345X@PJL\r\n@PJL INFO ID \r\n\e%-12345X" > /dev/usb/lp0

  echo -e "\e%-12345X@PJL\r\n@PJL INFO ID \r\n\e%-12345X" > /dev/usb/lp0

• Read PJL – I do not know when you should read and when the response is ready. So i try to read in loop or few cat commands, read or dd.

  #1way response=$(dd if=/dev/usb/lp0 of=temp.txt 2>&1) echo "$response" echo -e "\e" > /dev/usb/lp0   #2way while IFS= read -r -n1 char do printf "$char" done < /dev/usb/lp0 echo -e "\e" > /dev/usb/lp0   #3way cat /dev/usb/lp0 echo -e "\e" > /dev/usb/lp0

  #1wayresponse=$(dd if=/dev/usb/lp0 of=temp.txt 2>&1)echo "$response"echo -e "\e" > /dev/usb/lp0#2waywhile IFS= read -r -n1 chardo printf "$char"done < /dev/usb/lp0 echo -e "\e" > /dev/usb/lp0#3waycat /dev/usb/lp0echo -e "\e" > /dev/usb/lp0

• Example script to read the printer ID:

  #!/bin/bash   PRINTER=/dev/usb/lp0 ESCAPE=$(echo -e "\e") FF=$(echo -e "\x0C") char="" IFS="" echo "" > temp.txt   while true do sleep 0.5 #WAIT FOR NOT BUSY while true do fuser -s "$PRINTER" if [ $? -ne 0 ] then break fi done #send PJL to printer echo -e "\e%-12345X@PJL\r\n@PJL INFO ID \r\n\e%-12345X" > "$PRINTER" #TRY TO READ IMMEDIATELY char=$(dd if="$PRINTER" of=temp.txt 2>&1) echo -e "\e" > "$PRINTER" #CHECK THAT dd READ ANY BYTES echo "$char" | grep "bytes copied" > /dev/null if [ $? -ne 0 ] then printf "." else echo "$char" | grep "^0 bytes copied" > /dev/null if [ $? -ne 0 ] then cat temp.txt echo "" > temp.txt break else printf "." fi fi char="" done

  #!/bin/bashPRINTER=/dev/usb/lp0ESCAPE=$(echo -e "\e")FF=$(echo -e "\x0C")char=""IFS=""echo "" > temp.txt while true do sleep 0.5 #WAIT FOR NOT BUSY while true do fuser -s "$PRINTER" if [ $? -ne 0 ] then break fi done #send PJL to printer echo -e "\e%-12345X@PJL\r\n@PJL INFO ID \r\n\e%-12345X" > "$PRINTER" #TRY TO READ IMMEDIATELY char=$(dd if="$PRINTER" of=temp.txt 2>&1) echo -e "\e" > "$PRINTER" #CHECK THAT dd READ ANY BYTES echo "$char" | grep "bytes copied" > /dev/null if [ $? -ne 0 ] then printf "." else echo "$char" | grep "^0 bytes copied" > /dev/null if [ $? -ne 0 ] then cat temp.txt echo "" > temp.txt break else printf "." fi fi char="" done

  the response:
  @PJL INFO ID
"Brother HL-1110 series:84UE03:Ver1.08"