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63 lines
1.6 KiB
Groff
63 lines
1.6 KiB
Groff
.TH ACYCLIC 1 "21 March 2001"
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.SH NAME
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acyclic \- make directed graph acyclic
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.SH SYNOPSIS
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.B acyclic
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[
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.B \-nv?
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] [
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.B \-o
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.I outfile
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]
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[
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.I file
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]
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.SH DESCRIPTION
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.B acyclic
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is a filter that takes a directed graph as input and outputs
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a copy of the graph with sufficient edges reversed to make
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the graph acyclic. The reversed edge inherits all of the attributes
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of the original edge. The optional file argument specifies where the
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input graph is stored; by default, the program reads from \fBstdin\fP.
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.SH OPTIONS
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The following options are supported:
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.TP
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.B \-n
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No output is produced, though the return value
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will indicate whether the graph is acyclic or not.
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.TP
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.B \-v
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Print information about whether the file is acyclic, has a cycle or
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is undirected.
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.TP
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.BI \-o " outfile"
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causes the output to be written to the specified file; by default,
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output is written to \fBstdout\fP.
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.TP
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.B \-?
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option causes the program to print usage information.
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.SH RETURN CODES
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.B acyclic
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returns
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.B 0
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if the graph is acyclic;
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.B 1
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if the graph has a cycle;
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.B 2
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if the graph is undirected; and
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.B 255
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if there are any errors.
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.SH BUGS
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If the graph is strict and there is a cycle of length 2,
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the attributes of the reversed edge are lost.
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.PP
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Some edge attributes are non-symmetric, referring to either the head
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or tail node. At present, there is no mechanism or convention for
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correctly switching or renaming these.
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.SH AUTHORS
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Stephen C. North <north@research.att.com>
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.br
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Emden R. Gansner <erg@research.att.com>
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.SH "SEE ALSO"
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gc(1), dot(1), gvpr(1), gvcolor(1), ccomps(1), sccmap(1), tred(1), libgraph(3)
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