fbsql: add the --csv and --pset flags (#2342)

* fbsql: add the `--csv` flag for CSV output in non-interactive mode

* fbsql: add support for the `--pset=VAR[=ARG]` flag

cli/cli.go

@@ -110,6 +110,8 @@ func NewCommand(logdest logger.Logger) *Command {
 			},
 
 			HistoryPath: "",
+
+			CSV: false,
 		},
 
 		buffer:     newBuffer(),
@@ -167,7 +169,8 @@ func (cmd *Command) run(ctx context.Context) error {
 	// Check to see if Command needs to run in non-interactive mode.
 	if len(cmd.Commands) > 0 ||
 		len(cmd.Files) > 0 ||
-		cmd.Config.KafkaConfig != "" {
+		cmd.Config.KafkaConfig != "" ||
+		cmd.Config.CSV {
 		cmd.nonInteractiveMode = true
 	}
 
@@ -179,7 +182,12 @@ func (cmd *Command) run(ctx context.Context) error {
 	if err := cmd.setupClient(); err != nil {
 		return errors.Wrap(err, "setting up client")
 	}
-	cmd.printConnInfo()
+
+	// Print the connection info.
+	if !cmd.nonInteractiveMode {
+		cmd.printConnInfo()
+	}
+
 	if err := cmd.connectToDatabase(cmd.database); err != nil {
 		cmd.Errorf(errors.Wrap(err, "connecting to database").Error() + "\n")
 		// We intentionally do not return err here.
@@ -379,9 +387,45 @@ func (cmd *Command) setupConfig() error {
 
 	cmd.historyPath = cmd.Config.HistoryPath
 
+	// Apply any pset flag arguments.
+	for _, pset := range cmd.Config.PSets {
+		if err := cmd.applyPSet(pset); err != nil {
+			return errors.Wrapf(err, "applying pset: %s", pset)
+		}
+	}
+
+	// If running with the `--csv` flag, configure things to ensure the output
+	// is correct (i.e. that it's just the csv).
+	if cmd.Config.CSV {
+		cmd.writeOptions.format = formatCSV
+	}
+
 	return nil
 }
 
+// applyPSet takes a pset string of the form `arg` or `arg=val` and applies it
+// as if the user had run `\pset arg val`. The only difference is that applying
+// pset here suppresses any output to stdout.
+func (cmd *Command) applyPSet(pset string) error {
+	// We expect arg to be one of the folowing formats:
+	// arg
+	// arg=val
+	args := strings.SplitN(pset, "=", 2)
+
+	// This is kind of hacky, but until we re-think the metaCommand interface to
+	// take a printer interface somewhere (so we can pass in the nopPrinter
+	// here), we're just going to discard stdout for the duration of this apply,
+	// and then set stdout back to its previous writer after the apply.
+	hold := cmd.stdout
+	cmd.stdout = io.Discard
+	defer func() {
+		cmd.stdout = hold
+	}()
+
+	_, err := newMetaPSet(args).execute(cmd)
+	return err
+}
+
 func (cmd *Command) executeAndWriteQuery(qry query) error {
 	queryResponse, err := cmd.executeQuery(qry)
 	if err != nil {

cli/config.go

@@ -15,6 +15,12 @@ type Config struct {
 	KafkaConfig string `json:"kafka-config"`
 
 	HistoryPath string `json:"history-path"`
+
+	// CSV (Comma-Separated Values) table output mode.
+	CSV bool `json:"csv"`
+
+	// PSet takes one or more pset arguments of the form: `--pset=VAR[=ARG]`.
+	PSets []string `json:"pset"`
 }
 
 type CloudAuthConfig struct {

cmd/fbsql/main.go

@@ -59,6 +59,8 @@ func buildFlags(cmd *cobra.Command, cliCmd *cli.Command) {
 	flags.StringVar(&cliCmd.Config.CloudAuth.Password, "password", cliCmd.Config.CloudAuth.Password, "Password for FeatureBase Cloud access.")
 
 	flags.StringVar(&cliCmd.Config.KafkaConfig, "kafka-config", cliCmd.Config.KafkaConfig, "Kafka configuration file to read from.")
+	flags.BoolVar(&cliCmd.Config.CSV, "csv", cliCmd.Config.CSV, "CSV (Comma-Separated Values) table output mode.")
+	flags.StringSliceVar(&cliCmd.Config.PSets, "pset", cliCmd.Config.PSets, "Set printing option VAR to ARG (see \\pset command). Use form: --pset=VAR[=ARG]")
 
 	flags.String("config", "", "Configuration file to read from.")
 }