COINST(1)						      General Commands Manual							 COINST(1)

NAME

       Coinst - computes the co-installability kernel of a package repostory

SYNOPSIS

       coinst [options]

DESCRIPTION

       coinst  reads  a  package  repository  in debian format or RPM format from standard input, and computes the co-installability kernel of the
       repository (see below). The graph of the kernel is written in dot format to a file, and a diagnostic is written to  standard  output.  This
       diagnostic consists by default of:

	 - the list of equivalence classes of packages

	 - the list of non-installable packages

	 - the list of not co-installable pairs of packages

CO-INSTALLABILITY KERNELS
       A  set of packages is called co-installable with respect to a repository R if it can be extended to a set of packages from R that satisfies
       all inter-package relations (dependencies, conflicts, etc.). In particular, a package p is installable if the set {p} consisting of p  only
       is co-installable.

       This  tool reduces a repository R to a much smaller one, its so-called co-installability kernel R', that behaves exactly the same as far as
       co-installability of package is concerned: Any set of packages P is co-installable with respect to P iff it co-installable with respect	to
       R'. This is achieved by

	 - dropping  all  relations  that are not relevant for this purpose. For instance, dependencies that do not lead directly or indirectly to
	   any conflicts are dropped.

	 - identifying all packages that behave the same. For instance, packages that are not in conflict with any other package (even not through
	   dependency  chains)	behave the same since they are co-installable together with any other co-installable set of packages, and packages
	   that are not installable at all behave the same since they may never be part of any co-installable set of packages.

       A more precise explanation can be found in the original research article underlying this tool.

       The interest of computing the kernel is that it is typically orders of magnitude smaller than the original repository.

OPTIONS

   Options controlling the input
       -deb   expect input in the format of a debian Packages file (default).

       -rpm   expect input in the format of an RPM hdlist.cz file.

       -ignore package
	      ignore the package named package.

   Options controlling the graph output
       -o file
	      write the graph to file instead of graph.dot

       -all   include all packages in the coinstallability graph

       -root p
	      draw only the relevant portion of the graph around package p.

   Options controlling the diagnostic output
       -explain
	      explain the list of non-installable pairs of packages.

       -stats show statistics regarding the input and output repositories

   Miscellaneous options
       -help, --help
	      show command synopsis

EXAMPLE

       Reduce a current debian Packages file to its kernel:

	  coinst -all -o raw.dot < sid_main_binary-amd64_Packages

       Layout the graph:

	  dot raw.dot -o layout.dot:

       View the graph with dotty, or the viewer from the coinst_viewer package:

	  dotty layout.dot
	  coinst_viewer layout.dot

AUTHOR

       Coinst has been written by Jerome Vouillon.  This manpage has been compiled by Ralf Treinen from the original coinst documentation.

SEE ALSO

       dot(1),dotty(1),coinst_viewer(1)
       http://coinst.irill.org
       The original research article decribing the algorithm behind this tool is Roberto Di Cosmo and Jerome Vouillon, On software  component  co-
       installability,	19th  ACM  SIGSOFT Symposium on the Foundations of Software Engineering (FSE-19) and ESEC'11: 13rd European Software Engi-
       neering Conference (ESEC-13), Szeged, Hungary, September 5-9, 2011, pages 256-266.

																	 COINST(1)