printer_check

Unix Shell编程权威指南的配套源代码,书是好书,不过习题没有答案,要自己做了

#!/bin/bash
# Scriptname: printer_check
# Script to clear a hung-up printer
if [ $LOGNAME != root ]
then
	echo "Must have root privileges to run this program"
	exit 1
fi
cat << EOF
  Warning: All jobs in the printer queue will be removed.
  Please turn off the printer now. Press return when you
  are ready to continue. Otherwise press Control C.
EOF
read JUNK      # Wait until the user turns off the printer
echo
/etc/rc.d/init.d/lpd stop       # Stop the printer
echo -e "\nPlease turn the printer on now."
echo "Press Enter to continue"
read JUNK                # Stall until the user turns the printer 
                         # back on
echo                     # A blank line is printed
/etc/rc.d/init.d/lpd start     # Start the printer