lp – PostScript preprocessors

These programs are part of the lp(1) suite. Each corresponds to a process in the –pprocess option of lp and exists as an rc(1) script in /sys/lib/lp/process that provides an interface to a PostScript conversion program in /$cputype/bin/aux. The list of processors follows; after each description is a bracketed list of lp options to which the processor responds:
dpost     converts troff(1) output for device post to PostScript. This is used for files troff'ed on our UNIX systems that do not handle UTF characters. [DLcimnorxy]
dvipost    converts tex(1) output to PostScript. [Lcinor]
g3post    converts CCITT Group 3 FAX data to PostScript. [DLm]
gifpost    converts GIF image data to PostScript. [DLm]
generic    is the default processor. It uses file(1) to determine the type of input and executes the correct processor for a given (input, printer) pair.
hpost     adds a header page to the beginning of a PostScript printer job so that it may be separated from other jobs in the output bin. The header has the image of the job's owner from the directory of faces (see face(6)). Page reversal is also done in this processor.
jpgpost    converts JPEG image data to PostScript. [DLm]
noproc    passes files through untouched.
p9bitpostconverts a Plan 9 image to PostScript, such as /dev/screen for the whole screen, /dev/window for that window's data, and /dev/wsys/.../window for some other window's data. [DLm]
pdfpost   converts PDF data to PostScript.
post     passes PostScript through, adding option patches for paper tray information. This does not always work with PostScript generated on other systems.
ppost     converts UTF text to PostScript. [DLcfilmnorxy]
tr2post    converts troff(1) output for device utf (the default) to PostScript. See /sys/lib/troff/font/devutf directory for troff font width table descriptions. See also the /sys/lib/postscript/troff directory for mappings of troff UTF character space to PostScript font space. [DLcimnorxy]



The file command is not always smart enough to deal with certain file types. There are PostScript conversion programs that do not have processors to drive them.