[MacPorts] #50969: Provide a generic extract (and compress) commands in base

[MacPorts]

#50969: Provide a generic extract (and compress) commands in base
--------------------------+----------------------
  Reporter:  mojca@…      |      Owner:  raimue@…
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  base         |    Version:  2.3.4
Resolution:               |   Keywords:
      Port:               |
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Comment (by rjvbertin@…):

 > At the moment MacPorts supports fetching distfiles from different
 mirrors, but it doesn't support extracting different filetypes, so all the
 "hard work" of extracting the proper file has to be repeated manually in
 the Portfile.

 Shouldn't that read "would have to be repeated manually in the Portfile if
 an error wasn't raised by the automatic extraction process" and you don't
 rewrite the extract block yourself?

 I'd add a nice-to-have feature, at least until "base" provides an
 integrated way of fetching files in multiple formats:

 `file_fetch <name> [site]`

 that would do an on-demand fetch of the named file, looking it up on the
 `master_sites` or else from the given `site`. The site argument might be
 redundant if adding unused sites to master_sites has no negative side-
 effects.
 As far as I can see that would mostly require refactoring
 portfetch::fetchfiles from `portfetch.tcl` slightly, and exporting the
 procedure for extracting a single file.

 Here's an example from a work-in-progress Portfile of mine where such a
 function would come in handy:

 {{{
 post-fetch {
     if {![file exists ${distpath}/${qtwkdistfile}]} {
         ui_msg "--->  Fetching qtwebkit"
         # find a better way to fetch the archive with some form of
 optional progress
         # report that doesn't scroll
         system -W ${distpath} "wget --progress=bar:force:noscroll --quiet
 --show-progress
 https://github.com/qtproject/qtwebkit/archive/${qtwebkit_commit}/qtwebkit-
 snapshot.tar.gz"
         # give the file a more evocative name
         file rename ${distpath}/qtwebkit-snapshot.tar.gz
 ${distpath}/${qtwkdistfile}
     }
 }
 }}}

 I don't see how the automatic fetch/extract mechanism could achieve this -
 it would require syntax to tell fetch to save a given distfile under a
 different name, and extract to use that new name.

 I'd still need a manual extract, but that's probably required anyway (and
 not just because using hfsCompression really makes a difference here):

 {{{
 post-extract {
     if {![file exists ${distpath}/${qtwkdistfile}]} {
         ui_error "This shouldn't happen"
     } elseif {![file exists ${worksrcpath}/qtwebkit/.git] && [file exists
 ${distpath}/${qtwkdistfile}]} {
         ui_msg "--->  Extracting ${qtwkdistfile}"
         if {[file exists ${prefix}/bin/bsdtar]} {
             system -W ${worksrcpath} "bsdtar -x -k --hfsCompression -f
 ${distpath}/${qtwkdistfile}"
         } else {
             system -W ${worksrcpath} "tar -xf ${distpath}/${qtwkdistfile}"
         }
         file rename ${worksrcpath}/qtwebkit-${qtwebkit_commit}
 ${worksrcpath}/qtwebkit
         file mkdir ${worksrcpath}/qtwebkit/.git
     }
 }
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/50969#comment:2>
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