I have a shell script that is looping through a list of Postscript files to print.

ls -1tr *.PS > print.lst
...
PRINT_LIST=`cat print.lst`
...
for DMFILE in $PRINT_LIST
do
lp -d $PRINTER_NAME -o legal $DMFILE
...
done

The files in print.lst are in the order that they should be printed, however the order in which the files are printed appears to be completely random.

Here is a sample of print.lst, sequenced in the order to print

/prtspool/racprint/debitmemos/MNSF021.M0209137.PS
/prtspool/racprint/debitmemos/MNSF021.M0209138.PS
/prtspool/racprint/debitmemos/MNSF021.M0209139.PS
/prtspool/racprint/debitmemos/MNSF021.M0209140.PS
/prtspool/racprint/debitmemos/MNSF021.M0209141.PS
/prtspool/racprint/debitmemos/MNSF021.M0209142.PS
/prtspool/racprint/debitmemos/MNSF021.M0209143.PS
/prtspool/racprint/debitmemos/MNSF021.M0209144.PS

Here is the output from lpq:

active racuser 619 MNSF021.M0209137.PS 20200778 bytes
1st racuser 627 MNSF021.M0209145.PS 16781507 bytes
2nd racuser 621 MNSF021.M0209139.PS 20925819 bytes
3rd racuser 625 MNSF021.M0209143.PS 17315067 bytes
4th racuser 607 MNSF021.M0209125.PS 20202748 bytes
5th racuser 633 MNSF021.M0209151.PS 16825285 bytes
6th racuser 628 MNSF021.M0209146.PS 17372512 bytes
7th racuser 629 MNSF021.M0209147.PS 17078571 bytes
8th racuser 606 MNSF021.M0209124.PS 20928279 bytes
9th racuser 610 MNSF021.M0209128.PS 20928424 bytes

Why are the files printing in this seemingly random order? Is there a way that I can force the files to print in the order submitted?

Thanks, MB