Hooks manipulate a data stream without modifying the original stream.If the data should be modified before being sent to a hook or the printer a filter should be defined. Hooks may be scripts and do not alter the data which are sent to the printer. There can be only one filter per print queue but as many hooks as wanted can be specified for the same print queue. The manipulation of data before reaching the backend may be done via a combination of prehooks, posthooks and a filter. | | | cups-filters | | filter | | | backend | | | |

| Input file |->| + |->| wrapped |->| wrapped |->| Printer |

| | | CUPS | DATA1 | Tea4CUPS | DATA2 | Tea4CUPS | DATA3 | | Whether data are sent to the backend depends on the device-uri employed or the use of exit -1 in a prehook (see /etc/cups/nf and the example with pretendq). The Tea4CUPS wrapper script controls the execution of the chosen backend and, prior to that process, the data sent to it. It is a script (written in Python) that wraps round the chosen backend to manipulate print data before or after they are dispatched by the backend to the printer. Tea4CUPS is not intended to replace the function of any existing backend being used with the printer. The final filter a print job passes through before being sent to a printer is the backend filter (usb, parallel, socket etc), which transports the printer-ready job to the printer.

Creating a PDF/A Document with Ghostscript.

Creating Searchable PDFs from Text Files (2).

Creating Searchable PDFs from Text Files (1).

Printing Microsoft and Office Documents.

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