NAME
ccomps - connected components filter for graphs
SYNOPSIS
ccomps [ -sxvnzC? ] [ -X[#]v ] [ -ooutfile ] [ files ]
DESCRIPTION
ccomps decomposes graphs into their connected components, printing the
components to standard output.
OPTIONS
The following options are supported:
-s No output graph is printed. The return value can be used to
check if the graph is connected or not.
-x Only the connected components are printed, as separate graphs.
-v Counts of nodes, edges and connected components are printed.
-z Sort components by size, with the largest first. This is only
effective if either -x or -X#v is present. Thus, -zX#0 will
cause the largest component to be printed.
-C Use clusters in computing components in addition to normal edge
connectivity. In essence, this gives the connected components of
the derived graph in which nodes top-level clusters and nodes in
the original graph. This maintains all subgraph structure within
a component, even if a subgraph does not contain any nodes.
-n Do not project subgraph structure. Normally, if ccomps produces
components as graphs distinct from the input graph, it will
define subgraphs which are projections of subgraphs of the input
graph onto the component. (If the projection is empty, no
subgraph is produced.) If this flag is set, the component
contains only the relevant nodes and edges.
-X node_name
Prints only the component containing the node node_name, if any.
-X# index
Prints only component number index, if any, starting at 0.
-o outfile
If specified, each graph will be written to a different file
with the names derived from outfile. In particular, if both -o
and -x flags are used, then each connected component is written
to a different file. If outfile does not have a suffix, the
first file will have the name outfile; then next outfile_1, then
next outfile_2, and so on. If outfile has a suffix, i.e., has
the form base.sfx, then the files will be named base.sfx,
base_1.sfx, base_2.sfx, etc.
By default, each input graph is printed, with each connected component
given as a subgraph whose name is a concatenation of the name of the
input graph, the string "_component_" and the number of the component.
OPERANDS
The following operand is supported:
files Names of files containing 1 or more graphs in dot format. If
no files operand is specified, the standard input will be used.
RETURN CODES
Unless used to extract a single connected component, ccomps returns 0
if all the input graphs are connected; and non-zero if any graph has
multiple components, or any error occurred. If just extracting a
single component, ccomps returns 0 on success and non-zero if an error
occurred.
BUGS
It is possible, though unlikely, that the names used for connected
components and their subgraphs may conflict with existing subgraph
names.
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), acyclic(1), sccmap(1), tred(1),
libgraph(3)
27 August 2008