1ACYCLIC(1)                  General Commands Manual                 ACYCLIC(1)
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NAME

6       acyclic - make directed graph acyclic
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SYNOPSIS

9       acyclic [ -nv?  ] [ -o outfile ] [ file ]
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DESCRIPTION

12       acyclic  is a filter that takes a directed graph as input and outputs a
13       copy of the graph with sufficient edges  reversed  to  make  the  graph
14       acyclic. The reversed edge inherits all of the attributes of the origi‐
15       nal edge. The optional file argument  specifies  where  the  the  input
16       graph is stored; by default, the program reads from stdin.
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OPTIONS

19       The following options are supported:
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21       -n     No  output  is  produced,  though the return value will indicate
22              whether the graph is acyclic or not.
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24       -v     Print information about whether the file is acyclic, has a cycle
25              or is undirected.
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27       -o outfile
28              causes  the  output  to  be  written  to  the specified file; by
29              default, output is written to stdout.
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31       -?     option causes the program to print usage information.
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RETURN CODES

34       acyclic returns 0 if the graph is acyclic; 1 if the graph has a  cycle;
35       2 if the graph is undirected; and 255 if there are any errors.
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BUGS

38       If the graph is strict and there is a cycle of length 2, the attributes
39       of the reversed edge are lost.
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41       Some edge attributes are non-symmetric, referring to either the head or
42       tail  node.  At  present,  there is no mechanism or convention for cor‐
43       rectly switching or renaming these.
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AUTHORS

46       Stephen C. North <north@research.att.com>
47       Emden R. Gansner <erg@research.att.com>
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SEE ALSO

50       gc(1), dot(1), gvpr(1), gvcolor(1), ccomps(1), sccmap(1), tred(1), lib‐
51       graph(3)
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55                                 21 March 2001                      ACYCLIC(1)