add external pager support via ES_JSON_PAGER (#65)

cmd/api.go

@@ -83,6 +83,16 @@ func ApiRepl(conf *cfg.Config) *cli.Command {
 		Aliases: []string{"shell"},
 		Usage:   "interactive API repl",
 
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:        "pager",
+				Usage:       "external viewer program (default:internal)",
+				Destination: &conf.Pager,
+				Aliases:     []string{"p"},
+				Sources:     cli.EnvVars("PAGER", "ES_JSON_PAGER"),
+			},
+		},
+
 		Action: func(ctx context.Context, cmd *cli.Command) error {
 			return es.ApiRepl(conf)
 		},