NAME¶

acyclic - make directed graph acyclic

SYNOPSIS¶

acyclic[-nv?] [-ooutfile][file]

DESCRIPTION¶

acyclicis a filter that takes a directed graph as input and outputsa copy of the graph with sufficient edges reversed to makethe graph acyclic. The reversed edge inherits all of the attributesof the original edge. The optional file argument specifies where theinput graph is stored; by default, the program reads from stdin.

OPTIONS¶

The following options are supported:

-n

No output is produced, though the return valuewill indicate whether the graph is acyclic or not.

-v

Print information about whether the file is acyclic, has a cycle oris undirected.

-o outfile

causes the output to be written to the specified file; by default,output is written to stdout.

-?

option causes the program to print usage information.

RETURNCODES¶

acyclicreturns0if the graph is acyclic;1if the graph has a cycle;2if the graph is undirected; and255if there are any errors.

BUGS¶

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 heador tail node. At present, there is no mechanism or convention forcorrectly switching or renaming these.

AUTHORS¶

Stephen C. North <north@research.att.com>
Emden R. Gansner <erg@research.att.com>

SEE ALSO¶

gc(1), dot(1), gvpr(1), gvcolor(1), ccomps(1), sccmap(1), tred(1), libgraph(3)