gvpack.cpp

Go to the documentation of this file.

 
/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
 
/*
 * Written by Emden R. Gansner
 */
 
 
 
#include "config.h"
 
#include <getopt.h>
#include <algorithm>
#include <assert.h>
#include <gvc/gvc.h>
#include <cgraph/alloc.h>
#include <cgraph/exit.h>
#include <cgraph/ingraphs.h>
#include <cgraph/startswith.h>
#include <common/render.h>
#include <common/utils.h>
#include <neatogen/neatoprocs.h>
#include <iostream>
#include <limits>
#include <map>
#include <pack/pack.h>
#include <set>
#include <stddef.h>
#include <string>
#include <utility>
#include <vector>
#include "openFile.h"
 
extern "C" {
#ifdef GVDLL
  __declspec(dllimport)
#endif
extern gvplugin_library_t gvplugin_neato_layout_LTX_library;
}
 
lt_symlist_t lt_preloaded_symbols[] = {
#ifdef GVDLL
        { "gvplugin_neato_layout_LTX_library", 0 },
#else
        { "gvplugin_neato_layout_LTX_library", &gvplugin_neato_layout_LTX_library },
#endif
        { 0, 0 }
};
 
/* gvpack:
 * Input consists of graphs in dot format.
 * The graphs should have pos, width and height set for nodes, 
 * bb set for clusters, and, optionally, spline info for edges.
 * The graphs are packed geometrically and combined
 * into a single output graph, ready to be sent to neato -s -n2.
 *  -m <i> specifies the margin, in points, about each graph.
 */
 
typedef struct {
    Dtlink_t link;
    char *name;
    char *value;
    size_t cnt;
} attr_t;
 
typedef struct {
    Dtlink_t link;
    char *name;
    size_t cnt;
} pair_t;
 
static int verbose = 0;
static char **myFiles = 0;
static FILE *outfp;             /* output; stdout by default */
static Agdesc_t kind;           /* type of graph */
static std::vector<attr_t> G_args; // Storage for -G arguments
static bool doPack;              /* Do packing if true */
static char* gname = const_cast<char*>("root");
 
#define NEWNODE(n) ((node_t*)ND_alg(n))
 
static const char useString[] =
    "Usage: gvpack [-gnuv?] [-m<margin>] {-array[_rc][n]] [-o<outf>] <files>\n\
  -n          - use node granularity\n\
  -g          - use graph granularity\n\
  -array*     - pack as array of graphs\n\
  -G<n>=<v>   - attach name/value attribute to output graph\n\
  -m<n>       - set margin to <n> points\n\
  -s<gname>   - use <gname> for name of root graph\n\
  -o<outfile> - write output to <outfile>\n\
  -u          - no packing; just combine graphs\n\
  -v          - verbose\n\
  -?          - print usage\n\
If no files are specified, stdin is used\n";
 
static void usage(int v)
{
    std::cout << useString;
    graphviz_exit(v);
}
 
/* setNameValue:
 * If arg is a name-value pair, add it to the list
 * and return 0; otherwise, return 1.
 */
static int setNameValue(char *arg)
{
    char *rhs = const_cast<char*>("true");
 
    if (char *p = strchr(arg, '=')) {
        *p++ = '\0';
        rhs = p;
    }
    G_args.push_back(attr_t{{0, {0}}, arg, rhs, 0});
 
    return 0;
}
 
/* setUInt:
 * If arg is an integer, value is stored in v
 * and function returns 0; otherwise, returns 1.
 */
static int setUInt(unsigned int *v, char *arg)
{
    char *p;
    unsigned int i;
 
    i = (unsigned int) strtol(arg, &p, 10);
    if (p == arg) {
        std::cerr << "Error: bad value in flag -" << (arg - 1) << " - ignored\n";
        return 1;
    }
    *v = i;
    return 0;
}
 
static Agsym_t *agraphattr(Agraph_t *g, char *name, const char *value) {
    return agattr(g, AGRAPH, name, value);
}
 
static Agsym_t *agnodeattr(Agraph_t *g, char *name, const char *value) {
    return agattr(g, AGNODE, name, value);
}
 
static Agsym_t *agedgeattr(Agraph_t *g, char *name, const char *value) {
    return agattr(g, AGEDGE, name, value);
}
 
static void init(int argc, char *argv[], pack_info* pinfo)
{
    int c;
 
    agnodeattr(nullptr, const_cast<char*>("label"), NODENAME_ESC);
    pinfo->mode = l_clust;
    pinfo->margin = CL_OFFSET;
    pinfo->doSplines = true; // Use edges in packing
    pinfo->fixed = nullptr;
    pinfo->sz = 0;
 
    opterr = 0;
    while ((c = getopt(argc, argv, ":na:gvum:s:o:G:?")) != -1) {
        switch (c) {
        case 'a': {
            auto buf = std::string("a") + optarg + "\n";
            parsePackModeInfo(buf.c_str(), pinfo->mode, pinfo);
            break;
        }
        case 'n':
            parsePackModeInfo ("node", pinfo->mode, pinfo);
            break;
        case 's':
            gname = optarg;
            break;
        case 'g':
            parsePackModeInfo ("graph", pinfo->mode, pinfo);
            break;
        case 'm':
            setUInt(&pinfo->margin, optarg);
            break;
        case 'o':
            if (outfp != nullptr)
                fclose(outfp);
            outfp = openFile("gvpack", optarg, "w");
            break;
        case 'u':
            pinfo->mode = l_undef;
            break;
        case 'G':
            if (*optarg)
                setNameValue(optarg);
            else
                std::cerr << "gvpack: option -G missing argument - ignored\n";
            break;
        case 'v':
            verbose = 1;
            Verbose = 1;
            break;
        case ':':
            std::cerr << "gvpack: option -" << (char)optopt
                      << " missing argument - ignored\n";
            break;
        case '?':
            if (optopt == '\0' || optopt == '?')
                usage(0);
            else {
                std::cerr << "gvpack: option -" << (char)optopt << " unrecognized\n";
                usage(1);
            }
            break;
        }
    }
    argv += optind;
    argc -= optind;
 
    if (argc > 0) {
        myFiles = argv;
    }
    if (!outfp)
        outfp = stdout;         /* stdout the default */
    if (verbose)
        std::cerr << "  margin " << pinfo->margin << '\n';
}
 
/* init_node_edge:
 * initialize node and edge attributes
 */
static void init_node_edge(Agraph_t * g)
{
    node_t *n;
    edge_t *e;
    int nG = agnnodes(g);
    attrsym_t *N_pos = agfindnodeattr(g, const_cast<char*>("pos"));
    attrsym_t *N_pin = agfindnodeattr(g, const_cast<char*>("pin"));
 
    for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
        neato_init_node(n);
        user_pos(N_pos, N_pin, n, nG);  /* set user position if given */
    }
    for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
        for (e = agfstout(g, n); e; e = agnxtout(g, e))
            common_init_edge(e);
    }
}
 
/* init_graph:
 * Initialize attributes. We always do the minimum required by
 * libcommon. If fill is true, we use init_nop (neato -n) to
 * read in attributes relevant to the layout.
 */
static void init_graph(Agraph_t *g, bool fill, GVC_t *gvc) {
    int d;
    node_t *n;
    edge_t *e;
 
    aginit (g, AGRAPH, "Agraphinfo_t", sizeof(Agraphinfo_t), true);
    aginit (g, AGNODE, "Agnodeinfo_t", sizeof(Agnodeinfo_t), true);
    aginit (g, AGEDGE, "Agedgeinfo_t", sizeof(Agedgeinfo_t), true);
    GD_gvc(g) = gvc;
    graph_init(g, false);
    d = late_int(g, agfindgraphattr(g, const_cast<char*>("dim")), 2, 2);
    if (d != 2) {
        std::cerr << "Error: graph " << agnameof(g) << " has dim = " << d
                  << " (!= 2)\n";
        graphviz_exit(1);
    }
    Ndim = GD_ndim(g) = 2;
    init_node_edge(g);
    if (fill) {
        if (int ret = init_nop(g, 0)) {
            if (ret < 0)
                std::cerr << "Error loading layout info from graph " << agnameof(g) << '\n';
            else if (ret > 0)
                std::cerr << "gvpack does not support backgrounds as found in graph "
                          << agnameof(g) << '\n';
            graphviz_exit(1);
        }
        if (Concentrate) { /* check for edges without pos info */
            for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
                for (e = agfstout(g, n); e; e = agnxtout(g, e)) {
                    if (ED_spl(e) == nullptr) ED_edge_type(e) = IGNORED;
                }
            }
        }
    }
}
 
/* cloneAttrs:
 * Copy all attributes from old object to new. Assume
 * attributes have been initialized.
 */
static void cloneDfltAttrs(Agraph_t *old, Agraph_t *new_graph, int kind) {
    Agsym_t *a;
 
    for (a = agnxtattr(old, kind, 0); a; a =  agnxtattr(old, kind, a)) {
        if (aghtmlstr(a->defval)) {
            char *s = agstrdup_html(new_graph, a->defval);
            agattr(new_graph, kind, a->name, s);
            agstrfree(new_graph, s); // drop the extra reference count we bumped for s
        } else {
            agattr(new_graph, kind, a->name, a->defval);
        }
    }
}
static void cloneAttrs(void *old, void *new_graph) {
    int kind = AGTYPE(old);
    Agsym_t *a;
    char* s;
    Agraph_t *g = agroot(old);
    Agraph_t *ng = agroot(new_graph);
 
    for (a = agnxtattr(g, kind, 0); a; a =  agnxtattr(g, kind, a)) {
        s = agxget (old, a);
        if (aghtmlstr(s)) {
            char *scopy = agstrdup_html(ng, s);
            agset(new_graph, a->name, scopy);
            agstrfree(ng, scopy); // drop the extra reference count we bumped for scopy
        } else {
            agset(new_graph, a->name, s);
        }
    }
}
 
/* cloneEdge:
 * Note that here, and in cloneNode and cloneCluster,
 * we do a shallow copy. We thus assume that attributes
 * are not disturbed. In particular, we assume they are
 * not deallocated.
 */
static void cloneEdge(Agedge_t *old, Agedge_t *new_edge) {
  cloneAttrs(old, new_edge);
  ED_spl(new_edge) = ED_spl(old);
  ED_edge_type(new_edge) = ED_edge_type(old);
  ED_label(new_edge) = ED_label(old);
  ED_head_label(new_edge) = ED_head_label(old);
  ED_tail_label(new_edge) = ED_tail_label(old);
  ED_xlabel(new_edge) = ED_xlabel(old);
}
 
static void cloneNode(Agnode_t *old, Agnode_t *new_node) {
  cloneAttrs(old, new_node);
  ND_coord(new_node).x = POINTS(ND_pos(old)[0]);
  ND_coord(new_node).y = POINTS(ND_pos(old)[1]);
  ND_height(new_node) = ND_height(old);
  ND_ht(new_node) = ND_ht(old);
  ND_width(new_node) = ND_width(old);
  ND_lw(new_node) = ND_lw(old);
  ND_rw(new_node) = ND_rw(old);
  ND_shape(new_node) = ND_shape(old);
  ND_shape_info(new_node) = ND_shape_info(old);
  ND_xlabel(new_node) = ND_xlabel(old);
}
 
static void cloneCluster(Agraph_t *old, Agraph_t *new_cluster) {
  // string attributes were cloned as subgraphs
  GD_label(new_cluster) = GD_label(old);
  GD_bb(new_cluster) = GD_bb(old);
}
 
namespace {
struct AttributeValue {
  std::string value; 
  size_t instances;  
};
} // namespace
 
using attr_map_t = std::map<std::string, AttributeValue>;
 
/* fillDict:
 * Fill newdict with all the name-value attributes of
 * objp. If the attribute has already been defined and
 * has a different default, set default to "".
 */
static void fillDict(attr_map_t &newdict, Agraph_t *g, int kind) {
 
  for (Agsym_t *a = agnxtattr(g, kind, 0); a; a = agnxtattr(g, kind, a)) {
    char *name = a->name;
    char *value = a->defval;
    auto it = newdict.find(name);
    if (it == newdict.end()) {
      newdict.insert({name, AttributeValue{value, 1}});
    } else if (it->second.value == value)
      ++it->second.instances;
  }
}
 
/* fillGraph:
 * Use all the name-value entries in the dictionary d to define
 * to define universal node/edge/graph attributes for g.
 * For a non-empty default value, the attribute must be defined and the
 * same in all graphs.
 */
static void fillGraph(Agraph_t *g, const attr_map_t &d,
                      Agsym_t *(*setf)(Agraph_t *, char *, const char *),
                      size_t cnt) {
  for (const auto &kv : d) {
    const std::string &name = kv.first;
    const std::string &value = kv.second.value;
    const size_t &attr_cnt = kv.second.instances;
    if (cnt == attr_cnt)
      setf(g, const_cast<char *>(name.c_str()), value.c_str());
    else
      setf(g, const_cast<char *>(name.c_str()), "");
  }
}
 
/* initAttrs:
 * Initialize the attributes of root as the union of the
 * attributes in the graphs gs.
 */
static void initAttrs(Agraph_t *root, std::vector<Agraph_t*> &gs) {
    attr_map_t n_attrs;
    attr_map_t e_attrs;
    attr_map_t g_attrs;
 
    for (Agraph_t *g : gs) {
        fillDict(g_attrs, g, AGRAPH);
        fillDict(n_attrs, g, AGNODE);
        fillDict(e_attrs, g, AGEDGE);
    }
 
    fillGraph(root, g_attrs, agraphattr, gs.size());
    fillGraph(root, n_attrs, agnodeattr, gs.size());
    fillGraph(root, e_attrs, agedgeattr, gs.size());
}
 
static void cloneGraphAttr(Agraph_t * g, Agraph_t * ng)
{
    cloneAttrs(g, ng);
    cloneDfltAttrs(g, ng, AGNODE);
    cloneDfltAttrs(g, ng, AGEDGE);
}
 
using used_t = std::multiset<std::string>;
 
/* xName:
 * Create a name for an object in the new graph using the
 * dictionary names and the old name. If the old name has not
 * been used, use it and add it to names. If it has been used,
 * create a new name using the old name and a number.
 * Note that returned string will immediately made into an agstring.
 */
static std::string xName(used_t &names, char *oldname) {
  size_t previous_instances = names.count(oldname);
  names.insert(oldname);
  if (previous_instances > 0) {
    return std::string(oldname) + "_gv" + std::to_string(previous_instances);
  }
  return oldname;
}
 
#define MARK(e) (ED_alg(e) = e)
#define MARKED(e) (ED_alg(e))
#define SETCLUST(g,h) (GD_alg(g) = h)
#define GETCLUST(g) ((Agraph_t*)GD_alg(g))
 
/* cloneSubg:
 * Create a copy of g in ng, copying attributes, inserting nodes
 * and adding edges.
 */
static void
cloneSubg(Agraph_t *g, Agraph_t *ng, Agsym_t *G_bb, used_t &gnames) {
    node_t *n;
    node_t *nn;
    edge_t *e;
    edge_t *ne;
    node_t *nt;
    node_t *nh;
    Agraph_t *subg;
    Agraph_t *nsubg;
 
    cloneGraphAttr(g, ng);
    if (doPack)
        agxset(ng, G_bb, "");   /* Unset all subgraph bb */
 
    /* clone subgraphs */
    for (subg = agfstsubg (g); subg; subg = agnxtsubg (subg)) {
        nsubg = agsubg(ng, const_cast<char*>(xName(gnames, agnameof(subg)).c_str()),
                       1);
        agbindrec (nsubg, "Agraphinfo_t", sizeof(Agraphinfo_t), true);
        cloneSubg(subg, nsubg, G_bb, gnames);
        /* if subgraphs are clusters, point to the new 
         * one so we can find it later.
         */
        if (is_a_cluster(subg))
            SETCLUST(subg, nsubg);
    }
 
    /* add remaining nodes */
    for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
        nn = NEWNODE(n);
        agsubnode(ng, nn, 1);
    }
 
    /* add remaining edges. libgraph doesn't provide a way to find
     * multiedges, so we add edges bottom up, marking edges when added.
     */
    for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
        for (e = agfstout(g, n); e; e = agnxtout(g, e)) {
            if (MARKED(e))
                continue;
            nt = NEWNODE(agtail(e));
            nh = NEWNODE(aghead(e));
            ne = agedge(ng, nt, nh, nullptr, 1);
            agbindrec (ne, "Agedgeinfo_t", sizeof(Agedgeinfo_t), true);
            cloneEdge(e, ne);
            MARK(e);
        }
    }
}
 
/* cloneClusterTree:
 * Given old and new subgraphs which are corresponding
 * clusters, recursively create the subtree of clusters
 * under ng using the subtree of clusters under g.
 */
static void cloneClusterTree(Agraph_t * g, Agraph_t * ng)
{
    int i;
 
    cloneCluster(g, ng);
 
    if (GD_n_cluster(g)) {
        GD_n_cluster(ng) = GD_n_cluster(g);
        GD_clust(ng) = reinterpret_cast<Agraph_t**>(gv_calloc(1 + GD_n_cluster(g), sizeof(Agraph_t*)));
        for (i = 1; i <= GD_n_cluster(g); i++) {
            Agraph_t *c = GETCLUST(GD_clust(g)[i]);
            GD_clust(ng)[i] = c;
            cloneClusterTree(GD_clust(g)[i], c);
        }
    }
}
 
/* cloneGraph:
 * Create and return a new graph which is the logical union
 * of the graphs gs. 
 */
static Agraph_t *cloneGraph(std::vector<Agraph_t*> &gs, GVC_t *gvc) {
    Agraph_t *root;
    Agraph_t *subg;
    Agnode_t *n;
    Agnode_t *np;
    Agsym_t *G_bb;
    bool doWarn = true;
 
    if (verbose)
        std::cerr << "Creating clone graph\n";
    root = agopen(gname, kind, &AgDefaultDisc);
    initAttrs(root, gs);
    G_bb = agfindgraphattr(root, const_cast<char*>("bb"));
    if (doPack) assert(G_bb);
 
    /* add command-line attributes */
    for (attr_t &a : G_args) {
        if (Agsym_t *rv = agfindgraphattr(root, a.name))
            agxset(root, rv, a.value);
        else
            agattr(root, AGRAPH, a.name, a.value);
    }
 
    /* do common initialization. This will handle root's label. */
    init_graph(root, false, gvc);
    State = GVSPLINES;
 
    used_t gnames; // dict of used subgraph names
    used_t nnames; // dict of used node names
    for (size_t i = 0; i < gs.size(); i++) {
        Agraph_t *g = gs[i];
        if (verbose)
            std::cerr << "Cloning graph " << agnameof(g) << '\n';
        GD_n_cluster(root) += GD_n_cluster(g);
        GD_has_labels(root) |= GD_has_labels(g);
 
        /* Clone nodes, checking for node name conflicts */
        for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
            if (doWarn && agfindnode(root, agnameof(n))) {
                std::cerr << "Warning: node " << agnameof(n) << " in graph[" << i << "] "
                          << agnameof(g) << " already defined\n"
                          << "Some nodes will be renamed.\n";
                doWarn = false;
            }
            np = agnode(root, const_cast<char*>(xName(nnames, agnameof(n)).c_str()),
                        1);
            agbindrec (np, "Agnodeinfo_t", sizeof(Agnodeinfo_t), true);
            ND_alg(n) = np;
            cloneNode(n, np);
        }
 
        /* wrap the clone of g in a subgraph of root */
        subg = agsubg(root, const_cast<char*>(xName(gnames, agnameof(g)).c_str()),
                      1);
        agbindrec (subg, "Agraphinfo_t", sizeof(Agraphinfo_t), true);
        cloneSubg(g, subg, G_bb, gnames);
    }
 
    /* set up cluster tree */
    if (GD_n_cluster(root)) {
        int j, idx;
        GD_clust(root) = reinterpret_cast<graph_t**>(gv_calloc(1 + GD_n_cluster(root), sizeof(graph_t*)));
 
        idx = 1;
        for (Agraph_t *g : gs) {
            for (j = 1; j <= GD_n_cluster(g); j++) {
                Agraph_t *c = GETCLUST(GD_clust(g)[j]);
                GD_clust(root)[idx++] = c;
                cloneClusterTree(GD_clust(g)[j], c);
            }
        }
    }
 
    return root;
}
 
/* readGraphs:
 * Read input, parse the graphs, use init_nop (neato -n) to
 * read in all attributes need for layout.
 * Return the list of graphs. If cp != nullptr, set it to the number
 * of graphs read.
 * We keep track of the types of graphs read. They all must be
 * either directed or undirected. If all graphs are strict, the
 * combined graph will be strict; other, the combined graph will
 * be non-strict.
 */
static std::vector<Agraph_t*> readGraphs(GVC_t *gvc) {
    std::vector<Agraph_t*> gs;
    ingraph_state ig;
    int kindUnset = 1;
 
    /* set various state values */
    PSinputscale = POINTS_PER_INCH;
    Nop = 2;
 
    newIngraph(&ig, myFiles);
    while (Agraph_t *g = nextGraph(&ig)) {
        if (verbose)
            std::cerr << "Reading graph " << agnameof(g) << '\n';
        if (agnnodes(g) == 0) {
            std::cerr << "Graph " << agnameof(g) << " is empty - ignoring\n";
            continue;
        }
        if (kindUnset) {
            kindUnset = 0;
            kind = g->desc;
        }
        else if (kind.directed != g->desc.directed) {
            std::cerr << "Error: all graphs must be directed or undirected\n";
            graphviz_exit(1);
        } else if (!agisstrict(g))
            kind = g->desc;
        init_graph(g, doPack, gvc);
        gs.push_back(g);
    }
 
    return gs;
}
 
/* compBB:
 * Compute the bounding box containing the graphs.
 * We can just use the bounding boxes of the graphs.
 */
static boxf compBB(std::vector<Agraph_t*> &gs) {
    boxf bb, bb2;
 
    bb = GD_bb(gs[0]);
 
    for (size_t i = 1; i < gs.size(); i++) {
        bb2 = GD_bb(gs[i]);
        bb.LL.x = std::min(bb.LL.x, bb2.LL.x);
        bb.LL.y = std::min(bb.LL.y, bb2.LL.y);
        bb.UR.x = std::max(bb.UR.x, bb2.UR.x);
        bb.UR.y = std::max(bb.UR.y, bb2.UR.y);
    }
 
    return bb;
}
 
#ifdef DEBUG
void dump(Agraph_t * g)
{
    node_t *v;
    edge_t *e;
 
    for (v = agfstnode(g); v; v = agnxtnode(g, v)) {
        std::cerr << agnameof(v) << '\n';
        for (e = agfstout(g, v); e; e = agnxtout(g, e)) {
            std::cerr << "  " << agnameof(agtail(e)) << " -- " << agnameof(aghead(e))
                      << '\n';
        }
    }
}
 
void dumps(Agraph_t * g)
{
    graph_t *subg;
 
    for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
        dump(subg);
        std::cerr << "====\n";
    }
}
#endif
 
int main(int argc, char *argv[])
{
    Agraph_t *g;
    pack_info pinfo;
    GVC_t * gvc;
 
    init(argc, argv, &pinfo);
 
    doPack = (pinfo.mode != l_undef);
 
#if defined(_WIN32)
    lt_preloaded_symbols[0].address = &gvplugin_neato_layout_LTX_library;
#endif
    gvc = gvContextPlugins(lt_preloaded_symbols, DEMAND_LOADING);
    std::vector<Agraph_t*> gs = readGraphs(gvc);
    if (gs.empty())
        graphviz_exit(0);
 
    /* pack graphs */
    if (doPack) {
        if (packGraphs(gs.size(), gs.data(), 0, &pinfo)) {
            std::cerr << "gvpack: packing of graphs failed.\n";
            graphviz_exit(1);
        }
    }
 
    /* create union graph and copy attributes */
    g = cloneGraph(gs, gvc);
 
    /* compute new top-level bb and set */
    if (doPack) {
        GD_bb(g) = compBB(gs);
        dotneato_postprocess(g);
        attach_attrs(g);
    }
    agwrite(g, outfp);
    graphviz_exit(0);
}