fix: pass generated filename as arg

Signed-off-by: ismael FALL <ismael.fall@epitech.eu>

cmd/depviz/main.go

@@ -78,6 +78,7 @@ var (
 	graphvizFlags = flag.NewFlagSet("graphviz", flag.ExitOnError)
 	graphvizLabel = graphvizFlags.String("label", "", "label to use for the graph")
 	graphvizType  = graphvizFlags.String("type", "svg", "output type (svg, png, dot)")
+	graphvizFile  = graphvizFlags.String("file", "", "output file (default: stdout)")
 )
 
 func main() {
@@ -376,6 +377,7 @@ func execGenGraphviz(ctx context.Context, args []string) error {
 		GenOpts: genOpts,
 		Label:   *graphvizLabel,
 		Type:    *graphvizType,
+		File:    *graphvizFile,
 	}
 
 	return dvcore.GenGraphviz(store, args, opts)

pkg/dvcore/graphviz.go

@@ -2,6 +2,7 @@ package dvcore
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
 	"github.com/cayleygraph/cayley"
@@ -20,6 +21,7 @@ type GraphvizOpts struct {
 	// graphviz
 	Label string
 	Type  string
+	File  string
 }
 
 func GenGraphviz(h *cayley.Handle, args []string, opts GraphvizOpts) error {
@@ -106,7 +108,10 @@ func GenGraphviz(h *cayley.Handle, args []string, opts GraphvizOpts) error {
 			_ = edge
 		}
 	}
-	return g.RenderFilename(graph, graphviz.Format(opts.Type), "graph."+opts.Type)
+	if opts.File == "" {
+		return g.Render(graph, graphviz.Format(opts.Type), os.Stdout)
+	}
+	return g.RenderFilename(graph, graphviz.Format(opts.Type), opts.File)
 }
 
 func fmtIRI(s quad.IRI) string {