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.if \nt>0 .Z
.F1
.DS
.ta 3n +3n +3n +3n +3n +3n +3n +3n +3n +3n +3n +3n
.sz -1
LP = open( 'lp' ); // open device
OF = IF = LP; // set defaults
if( 'of' ) OF = filter( 'of' ) -> LP;
// make OF filter
if( accounting at start 'as')
do accounting;
if( leader on open 'ld' ) `ld` -> OF;
// send leader
if( FF on open 'fo' ) `fo` -> OF;
// send FF
.sp 0.5
// check to see if banner required
do_banner =
(always banner 'ab'
|| (!suppress banner 'sb'
&& control file 'L' ));
if( ! header last 'hl' && do_banner ){
BP = OF; bnr = null;
if( banner start 'bs' ) bnr = 'bs'
else if( banner program 'bp' ) bnr = 'bp'
if( bnr ){
BP = filter( bnr ) -> OF;
}
short banner info -> BP;
if( BP != OF ) close( BP );
}
// suspend the OF filter
if( OF != LP ) suspend OF filter;
.\".sp 0.5
.\"for each data file df in job do
.\" // send FF between files of job
.\" if( !first job && ! suppress FF 'sf' ){
.\" if( OF != LP ) wake up OF filter;
.\" 'ff' -> OF;
.\" if( OF != LP ) suspend OF filter;
.\" }
.\" // get filter for job
.\" ?F = LP; // default - no filter
.\" format = jobformat;
.\" if( jobformat == 'f' or
.\" jobformat = 'l' ){
.\" format = 'f';
.\" }
.\" filter = format filter from printcap;
.\" if( filter ){
.\" ?F = filter( filter ) -> LP;
.\" }
.\" // send data file to printer
.\" // through filter
.\" data file -> ?F;
.\" // kill filter
.\" if( ?F != LP ) close( ?F )
.\"endfor
.\".sp 0.5
.\"// finish printing
.\"if( OF != LP ) wake up OF filter;
.\"if( header last 'hl' && do_banner ){
.\" if( ! no FF separator 'sf' )
.\" 'ff' -> OF;
.\" BP = OF; bnr = null;
.\" if( banner end program 'be' ) bnr = 'be'
.\" else if( banner program 'bp' ) bnr = 'bp'
.\" if( bnr ){
.\" BP = filter( bnr ) -> OF;
.\" }
.\" short banner info -> BP;
.\" if( BP != OF ) close( BP );
.\"}
.\".sp 0.5
.\"if( ff on close 'fq' ) 'ff' -> OF;
.\"if( trailer on close 'tr' ) tr -> OF;
.\"if( accounting at end 'ae') do accounting;
.\"if( OF != LP ) close( OF );
.\"close( LP );
.sz +1
.DE
.FG "Figure 8a" "Printing algorithm used by LPRng
.if \nt=0 .F2
.if \nt>0 .ZZ
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