SYNOPSIS

#!/usr/bin/tclsh
package require gv

USAGE

Requires tcl8.3 or later.

INTRODUCTION

gv_tcl is a dynamically loaded extension for tcl that provides access to the graph facilities of graphviz.

COMMANDS

New graphs

New empty graph

<graph_handle> gv::graph <name>
<graph_handle> gv::digraph <name>
<graph_handle> gv::strictgraph <name>
<graph_handle> gv::strictdigraph <name>

New graph from a dot-syntax string or file

<graph_handle> gv::readstring <string>
<graph_handle> gv::read <string> filename
<graph_handle> gv::read <channel>

Add new subgraph to existing graph

<graph_handle> gv::graph <graph_handle> <name>

New nodes

Add new node to existing graph

<node_handle> gv::node <graph_handle> <name>

New edges

Add new edge between existing nodes

<edge_handle> gv::edge <tail_node_handle> <head_node_handle>

Add a new edge between an existing tail node, and a named head node which will be induced in the graph if it doesn't already exist

<edge_handle> gv::edge <tail_node_handle> <head_name>

Add a new edge between an existing head node, and a named tail node which will be induced in the graph if it doesn't already exist

<edge_handle> gv::edge <tail_name> <head_node_handle>

Add a new edge between named tail and head nodes which will be induced in the graph if they don't already exist

<edge_handle> gv::edge <graph_handle> <tail_name> <head_name>

Setting attribute values

Set value of named attribute of graph/node/edge - creating attribute if necessary

<string> gv::setv <graph_handle> <attr_name> <attr_value>
<string> gv::setv <node_handle> <attr_name> <attr_value>
<string> gv::setv <edge_handle> <attr_name> <attr_value>

Set value of existing attribute of graph/node/edge (using attribute handle)

<string> gv::setv <graph_handle> <attr_handle> <attr_value>
<string> gv::setv <node_handle> <attr_handle> <attr_value>
<string> gv::setv <edge_handle> <attr_handle> <attr_value>

Getting attribute values

Get value of named attribute of graph/node/edge

<string> gv::getv <graph_handle> <attr_name>
<string> gv::getv <node_handle> <attr_name>
<string> gv::getv <edge_handle> <attr_name>

Get value of attribute of graph/node/edge (using attribute handle)

<string> gv::getv <graph_handle> <attr_handle>
<string> gv::getv <node_handle> <attr_handle>
<string> gv::getv <edge_handle> <attr_handle>

Obtain names from handles

<string> gv::nameof <graph_handle>
<string> gv::nameof <node_handle>
<string> gv::nameof <attr_handle>

Find handles from names

<graph_handle> gv::findsubg <graph_handle> <name>
<node_handle> gv::findnode <graph_handle> <name>
<edge_handle> gv::findedge <tail_node_handle> <head_node_handle>
<attr_handle> gv::findattr <graph_handle> <name>
<attr_handle> gv::findattr <node_handle> <name>
<attr_handle> gv::findattr <edge_handle> <name>

Misc graph navigators returning handles

<node_handle> gv::headof <edge_handle>
<node_handle> gv::tailof <edge_handle>
<graph_handle> gv::graphof <graph_handle>
<graph_handle> gv::graphof <edge_handle>
<graph_handle> gv::graphof <node_handle>
<graph_handle> gv::rootof <graph_handle>

Obtain handles of proto node/edge for setting default attribute values

<node_handle> gv::protonode <graph_handle>
<edge_handle> gv::protoedge <graph_handle>

Iterators

Iteration termination tests

<boolean_string> gv::ok <graph_handle>
<boolean_string> gv::ok <node_handle>
<boolean_string> gv::ok <edge_handle>
<boolean_string> gv::ok <attr_handle>

Iterate over subgraphs of a graph

<graph_handle> gv::firstsubg <graph_handle>
<graph_handle> gv::nextsubg <graph_handle> <subgraph_handle>

Iterate over supergraphs of a graph (obscure and rarely useful)

<graph_handle> gv::firstsupg <graph_handle>
<graph_handle> gv::nextsupg <graph_handle> <subgraph_handle>

Iterate over edges of a graph

<edge_handle> gv::firstedge <graph_handle>
<edge_handle> gv::nextedge <graph_handle> <edge_handle>

Iterate over outedges of a graph

<edge_handle> gv::firstout <graph_handle>
<edge_handle> gv::nextout <graph_handle> <edge_handle>

Iterate over edges of a node

<edge_handle> gv::firstedge <node_handle>
<edge_handle> gv::nextedge <node_handle> <edge_handle>

Iterate over out-edges of a node

<edge_handle> gv::firstout <node_handle>
<edge_handle> gv::nextout <node_handle> <edge_handle>

Iterate over head nodes reachable from out-edges of a node

<node_handle> gv::firsthead <node_handle>
<node_handle> gv::nexthead <node_handle> <head_node_handle>

Iterate over in-edges of a graph

<edge_handle> gv::firstin <graph_handle>
<edge_handle> gv::nextin <node_handle> <edge_handle>

Iterate over in-edges of a node

<edge_handle> gv::firstin <node_handle>
<edge_handle> gv::nextin <graph_handle> <edge_handle>

Iterate over tail nodes reachable from in-edges of a node

<node_handle> gv::firsttail <node_handle>
<node_handle> gv::nexttail <node_handle> <tail_node_handle>

Iterate over nodes of a graph

<node_handle> gv::firstnode <graph_handle>
<node_handle> gv::nextnode <graph_handle> <node_handle>

Iterate over nodes of an edge

<node_handle> gv::firstnode <edge_handle>
<node_handle> gv::nextnode <edge_handle> <node_handle>

Iterate over attributes of a graph

<attr_handle> gv::firstattr <graph_handle>
<attr_handle> gv::nextattr <graph_handle> <attr_handle>

Iterate over attributes of an edge

<attr_handle> gv::firstattr <edge_handle>
<attr_handle> gv::nextattr <edge_handle> <attr_handle>

Iterate over attributes of a node

<attr_handle> gv::firstattr <node_handle>
<attr_handle> gv::nextattr <node_handle> <attr_handle>

Remove graph objects

<boolean_string> gv::rm <graph_handle>
<boolean_string> gv::rm <node_handle>
<boolean_string> gv::rm <edge_handle>

Layout

Annotate a graph with layout attributes and values using a specific layout engine

<boolean_string> gv::layout <graph_handle> <string> engine

Render

Render a layout into attributes of the graph

<boolean_string> gv::render <graph_handle>

Render a layout to stdout

<boolean_string> gv::render <graph_handle> <string> format

Render to an open file

<boolean_string> gv::render <graph_handle> <string> format <channel> fout

Render a layout to an unopened file by name

<boolean_string> gv::render <graph_handle> <string> format <string> filename

Render to a string result

<string> gv::renderresult <graph_handle> ing <string> format
gv::renderresult <graph_handle> <string> format <string> outdata

Render to an open channel

<boolean_string> gv::renderchannel <graph_handle> <string> format <string> channelname

Render a layout to a malloc'ed string, to be free'd by the caller

(deprecated - too easy to leak memory)

(still needed for "eval [gv::renderdata $G tk]" )

<string> gv::renderdata <graph_handle> <string> format

Writing graph back to file

<boolean_string> gv::write <graph_handle> <string> filename
<boolean_string> gv::write <graph_handle> <channel>

KEYWORDS

graph, dot, neato, fdp, circo, twopi, tcl.