core/commands: Enable stdin arguments for 'add' and 'cat', resolves #542

core/commands/add.go

@@ -37,7 +37,7 @@ remains to be implemented.
 	},
 
 	Arguments: []cmds.Argument{
-		cmds.FileArg("path", true, true, "The path to a file to be added to IPFS").EnableRecursive(),
+		cmds.FileArg("path", true, true, "The path to a file to be added to IPFS").EnableRecursive().EnableStdin(),
 	},
 	Options: []cmds.Option{
 		cmds.OptionRecursivePath, // a builtin option that allows recursive paths (-r, --recursive)

core/commands/cat.go

@@ -18,7 +18,7 @@ it contains.
 	},
 
 	Arguments: []cmds.Argument{
-		cmds.StringArg("ipfs-path", true, true, "The path to the IPFS object(s) to be outputted"),
+		cmds.StringArg("ipfs-path", true, true, "The path to the IPFS object(s) to be outputted").EnableStdin(),
 	},
 	Run: func(req cmds.Request) (interface{}, error) {
 		node, err := req.Context().GetNode()