Ok here's my current version:
<span class="syntaxdefault">def self</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">path_knife</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">path</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">max</span><span class="syntaxkeyword">=</span><span class="syntaxdefault">60</span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault"> </span><span class="syntaxcomment"># make sure it's a Ruby path using '/'.<br /></span><span class="syntaxdefault"> path </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> File</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">expand_path</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">path</span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault"> if path</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">length </span><span class="syntaxkeyword">></span><span class="syntaxdefault"> max<br /> </span><span class="syntaxcomment"># cut the file path into 2 lines<br /></span><span class="syntaxdefault"> ok </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">((</span><span class="syntaxdefault">path</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">length</span><span class="syntaxkeyword">-</span><span class="syntaxdefault">1</span><span class="syntaxkeyword">)*</span><span class="syntaxdefault">0.45</span><span class="syntaxkeyword">).</span><span class="syntaxdefault">to_i<br /> cut </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> path</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">split</span><span class="syntaxkeyword">(</span><span class="syntaxcomment">//).each_with_index { |e,i|<br /></span><span class="syntaxdefault"> break i if</span><span class="syntaxkeyword">(</span><span class="syntaxdefault"> e</span><span class="syntaxkeyword">==</span><span class="syntaxstring">'/'</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">&&</span><span class="syntaxdefault"> i</span><span class="syntaxkeyword">>=</span><span class="syntaxdefault">ok </span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br /></span><span class="syntaxdefault"> cut </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> 0 unless cut</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(Integer)<br /></span><span class="syntaxdefault"> return </span><span class="syntaxstring">" #{path[0..cut]} \n #{path[(cut+1)..-1]} "</span><span class="syntaxdefault"> if cut</span><span class="syntaxkeyword">></span><span class="syntaxdefault">0<br /> end<br /> </span><span class="syntaxcomment"># otherwise, leave it as one line<br /></span><span class="syntaxdefault"> return </span><span class="syntaxstring">" #{path} "<br /></span><span class="syntaxdefault"> </span><span class="syntaxcomment">#<br /></span><span class="syntaxdefault">end </span><span class="syntaxcomment"># def<br /></span><span class="syntaxdefault"> </span>**EDIT: Added test after iterator, to set cut to 0, if a string had no '/' characters (in which case each_with_index just returns the array characters.)
Also removed frivolous line before iterator: cut = 0
EDIT 2:(2011-02-19) Simplified path substring references (line 11.)
Removed frivolous else clause (were lines 12 and 13.)**