NAME

       ccomps - connected components filter for graphs

SYNOPSIS

       ccomps [ -sxvenzC?  ] [ -X[#%]s[-f] ] [ -ooutfile ] [ files ]

DESCRIPTION

       ccomps  decomposes  graphs  into  their  connected  components, printing the components to
       standard output.

OPTIONS

       The following options are supported:

       -e     Do not induce edges in the connected components.

       -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# 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# start


       -X# start-
       -X# start-last
              Prints  only  components in the given range of indices. In the first form, only the
              component whose index is start, if any, is  printed.   In  the  second  form,  each
              component  whose  index  is at least start is printed. In the last form, only those
              components whose indices are in the range [Istart,last]  are  printed.   Thus,  the
              flag -x is equivalent to -X#0-.

       -X# min


       -X# min-
       -X# min-max
              Prints  only  components  in  the  given  range of sizes. In the first form, only a
              component whose size is min,  if  any,  is  printed.   In  the  second  form,  each
              component  whose  size  is  at  least  min is printed. In the last form, only those
              components whose sizes are in the range [Imin,max] are printed.

       -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  "_cc_"  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)

                                          30 April 2011                                 CCOMPS(1)