a2ps
GNU a2ps is an Any to PostScript filter. Of course it processes plain text files, but also pretty prints quite a few popular languages. Its slogan is precisely `` Do The Right Thing '', which means that though it is highly configurable, everything was made so that a novice user can do complicated PostScript manipulations. For instance, it has the ability to delegate the processing of some files to other filters (such as groff, texi2dvi, dvips, gzip etc.), what allows a uniform treatment (n-up, page selection, duplex etc.) of heterogeneous files.
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