Determining what a port will install... (more than pretty-print-*) [Soln]

[Eric Schuele]

Csaba Henk wrote:
> On Mon, Oct 03, 2005 at 11:55:28AM -0500, Eric Schuele wrote:
> 
>>Hello,
>>
>>Some time back I posted a question regarding how to determine what
>>ports/packages would need to be installed on my machine when I install a 
>>new (new to the local machine) port.
>>
>>For example, if I do not presently have openoffice installed... what
>>will get installed when I 'make install clean' it?  Note that I want the
>>differences between what is needed to build/run the port and what is
>>already present on the machine.
>>
>>At the time no one responded with a clear way to do this... so I finally
>>had a few minutes to write a script to do it for me.  I thought someone
>>else might find it useful... So I'm posting it here for comments and
>>thoughts (be gentle, I'm new to awk).
> 
> 
> Here is an improved/spoiled (decide by yourself) version. 

Improved.

> I aimed to
> sport a more orthogonal design and avoid some gotchas I run into (see
> comments in awk code).
> 
> --------------------------------
> #! /bin/sh
> 
> # Script to determine the differences between what is necessary for
> # a port, and what is already present on the local machine.
> 
> awkprgt='{
>         count = 0
>         pkgs = ""
>         for(i=5; i<=NF-2; i++) {
>           pkg = $i
> 
>           # the "if" is here to hack it around when you get:
>           # This port requires package(s) "" to build.

I never ran into this case.

>           if (pkg != "\"\"") {
>             if (index(pkg, "\"") == 1)
>               {pkg = substr(pkg, 2, length(pkg)-1)}
>             if (index(pkg, "\"") > 1)
>               {pkg = substr(pkg, 1, length(pkg)-1)}
>   
>             if ( system("pkg_info -e " pkg) == 1) {
>               pkgs = pkgs " " pkg
>               count++
>             }
>           }
>         }
> 
>         if ( count ) {
>           print "You need the following (%s) perequisites:"
>           print pkgs
>         }
>         else {
>           print "All (%s) prerequisites are present."
>         }
> 
>       }

I did see this on a few ports... but decided to handle it in the same 
fashion as `make pretty-print*`, for better or worse.  My initial 
response was to do as you did (and I believe that IS the right thing)... 
but I fell back to what the make target did.  But I prefer your soln.

>       END {
>         # triggered, eg., by audio/artswrapper (on my box, at least)
>         if( ! FNR) {
>           print "Bogus (empty) %s dependency information"
>         }
>       }
> '
> 
> awkit() {
>         # Resolve "%s"-s via sed is a blunt hack
>         # but good enough here and thus we don't have
>         # to care about the number of occurrences
>         awk "`echo "$awkprgt" | sed s/%s/$1/g`"
> }
> 
> 
> make pretty-print-build-depends-list | awkit build
> 
> make pretty-print-run-depends-list | awkit run
> --------------------------------
> 
> Alas... while I was making these changes, I succeeded to recall why I
> abandoned my earlier attempt to put together a script which fulfils this
> (highly desired) functionality.

I highly desire this too... but my initial post (some months ago) 
received less attention than I expected.  I find this functionality very 
useful, and was surprised solution didn't already exist.

> 
> Because all such scripts are fundamentally broken.
> 
> When make decides which ports to pull in, it doesn't only use the flat
> data of build and run dependencies, but uses its full Turing complete
> computing power. Eg., what happens when a port needs a postscript
> interpreter? 

Then do the pretty-print(s) not provide the useful information they 
appear to?  I mean, If the above were true then they would have no 
value... and should go away.  Or do they provide true but incomplete 
information?

> Should it use the AFPL or the GNU edition as a dependency?
> Of course, doing a favor toward one of them (and taking away user's
> choice) is unacceptable. So what happens is that make directly checks
> whether the gs executable is present.
> 
> See, for example, print/gv. Your script's output will include
> ghostscript-gnu-7.07_13 both as a build and a run dependency.
> Yet when I type make, my ghostscript-gnu-7.07_12 installation will
> be happily utilized as the following output snippet shows:

Is this not acceptable behavior since it is just a port revision? 
Shouldn't the revision be compatible in every way with the vendor's release?

> 
> => Checksum OK for gv-3.6.1.tar.gz.
> ===>  Patching for gv-3.6.1
> ===>  Applying FreeBSD patches for gv-3.6.1
> ===>   gv-3.6.1 depends on executable: gmake - found
> ===>   gv-3.6.1 depends on executable: gs - found
> ===>   gv-3.6.1 depends on shared library: Xaw3d - found
> ===>   gv-3.6.1 depends on shared library: X11.6 - found
> ===>  Configuring for gv-3.6.1
> 
> The approach taken by FreeBSD's ports is to have more flexibility but
> less predictability, and now we have to live with it. Maybe the Gentoo
> guys are the ones who succeeded to find the proper balance between these
> two quantities -- they made up a mini-markup-language for denoting
> dependencies, which is clever enough to cover all cases but it's still
> just an easy to parse flat data.
> 
> One solution for FreeBSD could be digging deep into the make backend of
> the ports framework and insert the necessary hooks everywhere to produce
> a reliable dry-run.
> 
> Or severely refactor the whole ports framework and switch to Gentoo style
> dependency handling. This won't happen any soon IMHO as ports API
> changes should be pushed through all ports...
> 
> (OFF: to have a bit of bitter laugh, I think Gentoo's portage suffers
> from a fundamental design flaw: they can't tune installation prefixes
> (which would be necessary to make it an acceptable cross platform 3rd
> party package manager, akin to pkgsrc, but it would have other uses, too).
> This is again such a thing which can be changed only by rewriting all of
> their e-builds.)
> 
> Regards,
> Csaba
> 

Thanks for contributing to the script.

-- 
Regards,
Eric