ccomps

decompose graphs into connected components

TLDR

Print components, each as a separate graph

$ ccomps -x [input.dot]

Write each component to a numbered file derived from outfile

$ ccomps -x -o [out.dot] [input.dot]

Print only the largest component

$ ccomps -z -x [input.dot]

Count the components, print only counts to stderr

$ ccomps -sv [input.dot]

Extract the component containing a specific node

$ ccomps -X [node_name] [input.dot]

Output components by size range (at least 5 nodes)

$ ccomps -x -X%5- [input.dot]

SYNOPSIS

ccomps [-svnxCe?] [-z] [-X[#%]v] [-o outfile] [files]

ccomps decomposes graphs into their connected components, printing the components to standard output. By default, every node ends up in some component; with -C the cluster subgraph structure is also used to determine connectivity.For undirected graphs it computes connected components; for directed graphs it treats edges as undirected (weakly connected). The tool is useful for filtering disconnected subgraphs out of a graph, isolating the component containing a node of interest, or pre-processing graphs before layout with dot, neato, etc.If no input file is given, the graph is read from standard input.

PARAMETERS

-s

Silent: print no output graph; useful with -v to just check connectivity.

-x

Print each connected component as a separate graph (instead of embedding them as subgraphs).

-X nodename_

Print only the component containing the named node.

-X# index[-[last]]

Print only the component(s) at the given index, or index range (last optional).

-X% min[-[max]]

Print only the component(s) whose node count falls in the given size range.

-z

Sort components by size, largest first. Only meaningful with -x or -X#.

-C

Use cluster subgraphs in addition to normal edge connectivity when computing components.

-e

Do not induce edges in the connected components.

-n

Do not project subgraph structure: components contain only relevant nodes and edges.

-v

Verbose: print counts of nodes, edges and components to stderr.

-o outfile

Write output to outfile. With multiple components, files are numbered (outfile, outfile\_1, ...).

Print usage information.

INSTALL

sudo apt install graphviz

sudo dnf install graphviz

sudo pacman -S graphviz

sudo apk add graphviz

sudo zypper install graphviz

brew install graphviz

nix profile install nixpkgs#graphviz

CAVEATS

Input must be in DOT format. For directed graphs only weakly connected components are computed. Memory usage scales with graph size. Node names must be unique for the -X nodename_ form to work as expected. The -X flag is overloaded: a plain name, a #-prefixed index, or a %-prefixed size selector.

HISTORY

ccomps is part of the Graphviz suite, originally developed at AT&T Labs Research starting in the early 1990s by Stephen North, Eleftherios Koutsofios, Emden Gansner and others. Graphviz was open-sourced in 2004 and continues to be actively maintained.