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+strong_conn(1) -- Find the strongly connected components of a directed graph
+======
+
+## SYNOPSIS
+
+`strong_conn` <graph_in> [SHOW]
+
+## DESCRIPTION
+
+`strong_conn` finds the strongly connected components of the directed
+graph given as input using the Kosaraju-Sharir algorithm, and prints
+the size of each of them. If the optional second parameter `SHOW` is
+provided, the program dumps on output also the list of nodes belonging
+to each component.
+
+## PARAMETERS
+
+* <graph_in>:
+    input graph (edge list) if equal to `-` (dash), read the edge list
+    from STDIN.
+
+
+* SHOW: 
+    If the (optional) second parameter is equal to `SHOW`, the program
+    will dump on output the list of all the nodes belonging to each
+    strongly connected component.
+
+## OUTPUT
+
+`strong_conn` prints on the standard output the size of all the
+strongly connected components of the directed graph given as input,
+one per line:
+
+        size_1
+        size_2
+        size_3
+        .....
+
+where `size_1` is the size of the first component, `size_2` is the
+size of the second component, and so on. Notice that the sizes are not
+sorted.  If `SHOW` is given, the program shows the list of nodes
+belonging to each strongly connected component, in the format:
+
+    size_1: node_1 node_2 node_3 ...
+    size_2: node_1 node_2 node_3 ...
+    
+## EXAMPLES
+
+The following command:
+
+          $ strong_conn web-NotreDame.net 
+          53968
+          1
+          1
+          1
+          1
+          1
+          1
+          ....
+          $
+
+shows on output the size of the strongly connected component of the
+graph `web-NotreDame.net` (the NotreDame WWW data set), in no particular
+order. In this case the graph has 203609 strongly connected
+components, most of them containing only 1 isolated node.  If we want
+to know who are the nodes belonging to each connected component, we
+run:
+
+          $ strong_conn web-NotreDame.net SHOW
+          53968: 0 1 3 4 5 6 7 8.....
+          ..... 325727 325728
+          1: 351
+          1: 350
+          1: 2209
+          1: 2208
+          1: 2206
+          1: 10609
+          ....
+          $
+
+It is better to save the output of `strong_conn` into a file, e.g. by
+using:
+
+          $ strong_conn web-NotreDame.net SHOW > web-NotreDame.net_scc
+
+## SEE ALSO
+
+components(1), node\_components(1), largest_component(1)
+
+
+## REFERENCES
+
+* V\. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles,
+  Methods and Applications", Chapter 6, Cambridge University Press
+  (2017)
+
+* V\. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles,
+  Methods and Applications", Appendix 8, Cambridge University Press
+  (2017)
+
+
+## AUTHORS
+
+(c) Vincenzo 'KatolaZ' Nicosia 2009-2017 `<v.nicosia@qmul.ac.uk>`.