Tech insights

Internet Printing Protocol Printing with  Internet Printing Protocol (IPP)  involves sending a Unirast   Format (URF) image with appropriate protocol headers to port 631. It is the basis for standards like  Windows Mopria Alliance , Apple   AirPrint , and IPP Everywhere .  It is also called  Driverless Printing   since this doesn't involve installing any printer specific driver. On Plan 9, printing involves three steps: Convert the document to PDF using lp Convert the PDF to URF using  gs  (use urfgray, urfrgb or urfcmyk device) Send the request to the printer using hget IPP header ( req.bin in the below script) contains page output options like paper size, margins etc. This is generated   using ippenc.c .        #!/bin/rc HOST=$1 FILE=$2 TFILE=/tmp/a.pdf URL=( http://$HOST:631/ipp/print/ ) if (! ~ $#* 2)    echo 'Usage: $0 <printer-ip> <file>'     lp -d stdout $FILE > $TFILE...

Unicode text (top) converted to PS file (bottom) Document printed using HP3545 printer Unicode RTL text (top) converted to PS file (bottom) ASCII text in Braille font (top) converted to PS file (bottom) Unicode CJK text (top) converted to PS file (bottom) Sheet music using Bravura Text (top) converted to PS file (bottom) Sudoko grid (top) converted to PS file (bottom) Text with fancy fonts (top) converted to PS file (bottom) Text file (left) converted to PS file (right) Welcome screen (left) with SVG image and font variations converted to PS file (right)   Full resolution JPG in image-mode (left) converted to fit in an A4 page (right)   Format a text file in text-mode. Please note that you need to use proportional font (aka variable pitch font) in the frame to have text with varying sizes.  DejaVuSans font is used in the screenshot. Also, be aware that font-lock-mode might interfere with the formatting. If you're unable to change formatting, try turning off font-lock-mod...