#!/usr/bin/ruby

# display the kernel module dependencies

#based on: modgraph.tcl by:  John Ellson <ellson@research.att.com>
#ruby adaptation by:         Patricio Ros <patricioros.dev@gmail.com>
#additional fixes:           Ralph Mueller <ralf.mueller@zmaw.de>

require 'gv'

G = Gv.digraph("G")
N = Gv.protonode(G)
E = Gv.protoedge(G)

Gv.setv(G, 'rankdir', 'LR')
Gv.setv(G, 'nodesep', '0.05')
Gv.setv(N, 'shape', 'box')
Gv.setv(N, 'width', '0')
Gv.setv(N, 'height', '0')
Gv.setv(N, 'margin', '.03')
Gv.setv(N, 'fontsize', '8')
Gv.setv(N, 'fontname', 'helvetica')
Gv.setv(E, 'arrowsize', '.4')

modules = File.open('/proc/modules', mode="r").readlines

modules.each {|rec|
   fields = rec.split(' ')
   n = Gv.node(G, fields[0])
   fields[3].split(',').each {|usedby|
      Gv.edge(n, Gv.node(G, usedby)) if (usedby != '-') and (usedby != '')
   }
}

Gv.layout(G, 'dot')
Gv.render(G, 'xlib')