---
name: "gvc"
section: "3"
platform: "linux"
package: "graphviz"
version: "16.1.0-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gvc"
---

# gvc(3)

Graphviz context library

## NAME

**libgvc** - Graphviz context library

## SYNOPSIS

```
#include <graphviz/gvc.h>
/* set up a graphviz context */
extern GVC_t *gvNEWcontext(const lt_symlist_t *builtins, int demand_loading);
/*  set up a graphviz context ‐ alternative */
/*     (wraps the above two functions using info built into libgvc) */
extern GVC_t *gvContext(void);
/* parse command line args ‐ minimally argv[0] sets layout engine */
extern int gvParseArgs(GVC_t *gvc, int argc, char **argv);
extern graph_t *gvNextInputGraph(GVC_t *gvc);
/* Compute a layout using a specified engine */
extern int gvLayout(GVC_t *gvc, graph_t *g, char *engine);
/* Compute a layout using layout engine from command line args */
extern int gvLayoutJobs(GVC_t *gvc, graph_t *g);
/* Check if a layout has been done */
extern bool gvLayoutDone(graph_t *g);
/* Render layout into string attributes of the graph */
extern void attach_attrs(graph_t *g);
/* Parse an html string */
extern char *agstrdup_html(char *s);
extern int aghtmlstr(char *s);
/* Render layout in a specified format to an open FILE */
extern int gvRender(GVC_t *gvc, graph_t *g, char *format, FILE *out);
/* Render layout in a specified format to an open FILE */
extern int gvRenderFilename(GVC_t *gvc, graph_t *g, char *format, char *filename);
/* Render layout according to -T and -o options found by gvParseArgs */
extern int gvRenderJobs(GVC_t *gvc, graph_t *g);
/* Clean up layout data structures ‐ layouts are not nestable (yet) */
extern int gvFreeLayout(GVC_t *gvc, graph_t *g);
/* Clean up graphviz context */
extern int gvFreeContext(GVC_t *gvc);
/* Inquire about available plugins */
/* See comment in gvc.h            */
extern char** gvPluginList(GVC_t *gvc, char* kind, int* cnt, char*);
```

## DESCRIPTION

*libgvc* provides a context for applications wishing to manipulate and render graphs.  It provides command line parsing, common rendering code, and a plugin mechanism for renderers.

## SEE ALSO

[**dot**(1)](/dot/1.md), [**neato**(1)](/neato/1.md), [**cdt**(3)](/cdt/3.md), [**cgraph**(3)](/cgraph/3.md)\

## AUTHOR

John Ellson (ellson@research.att.com), AT&T