acyclic - make directed graph acyclic
acyclic [ -nv? ] [ -o outfile ] [ file ]
acyclic is a filter that takes a directed graph as input and outputs a copy of the graph with sufficient edges reversed to make the graph acyclic. The reversed edge inherits all of the attributes of the original edge. The optional file argument specifies where the the input graph is stored; by default, the program reads from stdin.
The following options are supported:
acyclic returns 0 if the graph is acyclic; 1 if the graph has a cycle; 2 if the graph is undirected; and 255 if there are any errors.
If the graph is strict and there is a cycle of length 2, the attributes of the reversed edge are lost.
Some edge attributes are non-symmetric, referring to either the head or tail node. At present, there is no mechanism or convention for for correctly switching or renaming these.
Stephen C. North <firstname.lastname@example.org> Emden R. Gansner <email@example.com>