scripting lpr for print jobs

[timocharis]

I have a custom PHP application which creates a series of lpr commands which prints a booklet. I am using an HP 9050 with the optional 3000 page stacker unit.

The booklet is comprised of 3 postscript files. Seperate lpr commands are used for each postscript file because they use different paper types and use different input trays.

The script for 1 booklet looks like this.

lpr -P HP9050-ticket -o media=A4,tray1 /usr/local/apache2/htdocs/sysdocs/1144091.ps;

# Print 7 pages - Barcoded Tickets
lpr -P HP9050-ticket -# 7 -o media=A4,tray4Optional /usr/local/apache2/htdocs/sysdocs/1144090.ps;

# Print 1 page - blank page
lpr -P HP9050-ticket -o media=A4,tray3 /usr/oracle/9iASrel1/unified/reports/blank.ps;

I am printing many booklets and want to take advantage of the 'job offset' feature of the stacker unit. The problem is that the printer is seeing each postscript file as a seperate job and therefore offsets every page.

I can merge the seperate postscript files into 1 postscript file, print that and the booklets offset, BUT then I can't print from seperate trays because I am submitting it as 1 job.

Does anyone know if there is a way to group the lpr commands, or send a flag to the printer to not offset? Any ideas would be appreciated. Thanks.