2.2.3 Using Delegations

a2ps can decide that a2ps itself is not the right tool to do what you want. In that case it delegates the task to other programs. What you should retain from this, is, forget that there are delegations. Indeed, the interface with the delegations has been designed so that you don’t need to be aware that they exist to use them. Do as usual.

As an example, if you need to print a PostScript file, just hit:

gargantua ~ $ a2ps article.ps -d
[article.ps (ps, delegated to PsNup): 7 pages on 4 sheets]
[Total: 8 pages on 4 sheets] sent to the default printer

While honoring your defaults settings, a2ps delegates the task to put two virtual pages per physical page to psnup, a powerful filter part of the famous psutils by Angus Duggan.

Suppose now that you want to display a Texinfo file. Then, provided you have all the programs a2ps needs, just hit

gargantua ~ $ a2ps a2ps.texi -P display
[a2ps.texi (texinfo, delegated to texi2dvi): 75 pages on 38 sheets]
[Total: 76 pages on 38 sheets] sent to the printer `display'

Once the read documentation, you know you want to print just pages 10 to 20, plus the cover. Just hit:

gargantua ~ $ a2ps a2ps.texi --pages=1,10-20 -d
[a2ps.texi (texinfo, delegated to texi2dvi): 13 pages on 7 sheets]
[Total: 14 pages on 7 sheets] sent to the default printer

A final word: compressed files can be treated in the very same way:

gargantua ~ $ a2ps a2ps.texi.gz -a1,10-20 -d
[a2ps.texi (compressed, delegated to Gzip-a2ps): 13 pages on 7 sheets]
[Total: 14 pages on 7 sheets] sent to the default printer

You should be aware that:

• - the option ‘-Z’ enables the delegations if they are not (see ‘--list=defaults’ for your settings);
• - the set of delegations is customizable, to know the delegations your a2ps knows, consult ‘a2ps --list=delegations’.