core/commands: Added 'cat' command

core/commands/cat.go

@@ -4,26 +4,34 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/jbenet/go-ipfs/core"
+	cmds "github.com/jbenet/go-ipfs/commands"
 	uio "github.com/jbenet/go-ipfs/unixfs/io"
 )
 
-func Cat(n *core.IpfsNode, args []string, opts map[string]interface{}, out io.Writer) error {
-	for _, fn := range args {
-		dagnode, err := n.Resolver.ResolvePath(fn)
-		if err != nil {
-			return fmt.Errorf("catFile error: %v", err)
-		}
+var cat = &cmds.Command{
+	Help: "TODO",
+	Run: func(req cmds.Request, res cmds.Response) {
+		node := req.Context().Node
+		fmt.Println(node.Resolver)
+		readers := make([]io.Reader, 0, len(req.Arguments()))
 
-		read, err := uio.NewDagReader(dagnode, n.DAG)
-		if err != nil {
-			return fmt.Errorf("cat error: %v", err)
-		}
+		for _, path := range req.Arguments() {
+			dagnode, err := node.Resolver.ResolvePath(path)
+			if err != nil {
+				res.SetError(err, cmds.ErrNormal)
+				return
+			}
 
-		_, err = io.Copy(out, read)
-		if err != nil {
-			return fmt.Errorf("cat error: %v", err)
+			read, err := uio.NewDagReader(dagnode, node.DAG)
+			if err != nil {
+				res.SetError(err, cmds.ErrNormal)
+				return
+			}
+
+			readers = append(readers, read)
 		}
-	}
-	return nil
+
+		reader := io.MultiReader(readers...)
+		res.SetValue(reader)
+	},
 }

core/commands/root.go

@@ -43,6 +43,10 @@ Advanced Commands:
 Use "ipfs help <command>" for more information about a command.
 `,
 	Subcommands: map[string]*cmds.Command{
+		"cat": cat,
+
+		// test subcommands
+		// TODO: remove these when we don't need them anymore
 		"beep": &cmds.Command{
 			Run: func(req cmds.Request, res cmds.Response) {
 				v := &TestOutput{"hello, world", 1337}