Better comments.
 [rsc] --rwxrwxr-x M 913078 glenda sys 5140 Feb 13 09:03 rc/bin/lp
	/n/sourcesdump/2006/0213/plan9/rc/bin/lp:1,6 - 
	/n/sourcesdump/2006/0214/plan9/rc/bin/lp:1,7
	  #!/bin/rc
	- # This program enqueues the file to be printed and starts the daemon, when necessary.
	- # Make changes to /sys/src/cmd/lp/lp.rc.  Changes made directly to /rc/bin/lp will be lost.
	+ # lp - enqueues the file to be printed and starts the daemon, when necessary.
	+ # Make changes to /sys/src/cmd/lp/lp.rc;
	+ # changes made directly to /rc/bin/lp will be lost.
	  
	  rfork en	# so that environment and name space are not polluted
	  # 
	/n/sourcesdump/2006/0213/plan9/rc/bin/lp:138,143 - 
	/n/sourcesdump/2006/0214/plan9/rc/bin/lp:139,146
	  	LPLOC=`{echo $LPDEST|sed 's/^(.*)\/(.*)/\1/'}
	  	LPDEST=`{echo $LPDEST|sed 's/^(.*)\/(.*)/\2/'}
	  }
	+ 
	+ # look up device, get info
	  LPDLINE=`{grep '^'$LPDEST'[ 	]' $LPLIB/devices}
	  if (! ~ $status '') {
	  	echo 'device '$LPDEST' is not in '$LPLIB'/devices' >[1=2]
 [rsc] --rwxrwxr-x M 913078 glenda sys 5140 Feb 13 09:03 sys/src/cmd/lp/lp.rc
	/n/sourcesdump/2006/0213/plan9/sys/src/cmd/lp/lp.rc:1,6 - 
	/n/sourcesdump/2006/0214/plan9/sys/src/cmd/lp/lp.rc:1,7
	  #!/bin/rc
	- # This program enqueues the file to be printed and starts the daemon, when necessary.
	- # Make changes to /sys/src/cmd/lp/lp.rc.  Changes made directly to /rc/bin/lp will be lost.
	+ # lp - enqueues the file to be printed and starts the daemon, when necessary.
	+ # Make changes to /sys/src/cmd/lp/lp.rc;
	+ # changes made directly to /rc/bin/lp will be lost.
	  
	  rfork en	# so that environment and name space are not polluted
	  # 
	/n/sourcesdump/2006/0213/plan9/sys/src/cmd/lp/lp.rc:138,143 - 
	/n/sourcesdump/2006/0214/plan9/sys/src/cmd/lp/lp.rc:139,146
	  	LPLOC=`{echo $LPDEST|sed 's/^(.*)\/(.*)/\1/'}
	  	LPDEST=`{echo $LPDEST|sed 's/^(.*)\/(.*)/\2/'}
	  }
	+ 
	+ # look up device, get info
	  LPDLINE=`{grep '^'$LPDEST'[ 	]' $LPLIB/devices}
	  if (! ~ $status '') {
	  	echo 'device '$LPDEST' is not in '$LPLIB'/devices' >[1=2]