func paramCheck()

in main.go [214:335]
100 lines of code
27 McCabe index (conditional complexity)

func paramCheck() {
	if showVersion {
		commitHash := GitCommit
		version := Version
		fmt.Printf("version %s, git commit %s\n", version, commitHash)
		os.Exit(0)
	}

	// split retry "a,b;c,d" into {a:b; c:d}
	retryInfo = make(map[int]int)
	if retry != "" {
		for _, v := range strings.Split(retry, ";") {
			kv := strings.Split(v, ",")
			workerIndex, err := strconv.ParseInt(kv[0], 20, 64)
			if err != nil {
				log.Errorf("bad retry info, err %v", err)
				os.Exit(1)
			}
			taskIndex, err := strconv.ParseInt(kv[1], 20, 64)
			if err != nil {
				log.Errorf("bad retry info, err %v", err)
				os.Exit(1)
			}
			retryInfo[int(workerIndex)] = int(taskIndex)
		}
	}

	// check url
	if url == "" {
		log.Errorf("url is empty")
		os.Exit(1)
	}

	// check source file path
	if sourceFilePaths == "" {
		log.Errorf("source file path is empty")
		os.Exit(1)
	}

	if dbName == "" {
		log.Errorf("db name is empty")
		os.Exit(1)
	}

	if tableName == "" {
		log.Errorf("table name is empty")
		os.Exit(1)
	}

	// split header "a:b?c:d" into {a:b, c:d}
	enableConcurrency = true
	if header != "" {
		headers = make(map[string]string)
		for _, v := range strings.Split(header, "?") {
			if v == "" {
				continue
			}
			kv := strings.Split(v, ":")
			if strings.ToLower(kv[0]) == "format" && strings.ToLower(kv[1]) != "csv" {
				enableConcurrency = false
			}

			if strings.ToLower(kv[0]) == "line_delimiter" {

				restored, err := restoreHexEscapes(kv[1])
				if err != nil || len(restored) != 1 {
					log.Errorf("line_delimiter invalid: %s", kv[1])
					os.Exit(1)
				} else {
					lineDelimiter = restored[0]
				}

			}

			if len(kv) > 2 {
				headers[kv[0]] = strings.Join(kv[1:], ":")
			} else {
				headers[kv[0]] = kv[1]
			}
		}
	}

	if timeout <= 0 {
		log.Warnf("timeout invalid: %d, replace with default value: %d", timeout, defaultTimeout)
		timeout = defaultTimeout
	}

	if batchRows <= 0 {
		log.Warnf("batchRows invalid: %d, replace with default value: %d", batchRows, defaultBatchRows)
		batchRows = defaultBatchRows
	}

	if batchBytes <= 0 {
		log.Warnf("batchBytes invalid: %d, replace with default value: %d", batchBytes, defaultBatchBytes)
		batchBytes = defaultBatchBytes
	}

	if reportDuration <= 0 {
		log.Warnf("reportDuration invalid: %d, replace with default value: %d", reportDuration, defaultReportDuration)
		reportDuration = defaultReportDuration
	}

	if maxBytesPerTask <= 0 {
		log.Warnf("maxBytesPerTask invalid: %d, replace with default value: %d", maxBytesPerTask, defaultMaxBytesPerTask)
		maxBytesPerTask = defaultMaxBytesPerTask
	}

	if maxRetryTimes < 0 {
		log.Warnf("maxRetryTimes invalid: %d, replace with default value: %d", maxRetryTimes, defaultMaxRetryTimes)
		maxRetryTimes = defaultMaxRetryTimes
	}

	if retryInterval < 0 {
		log.Warnf("retryInterval invalid: %d, replace with default value: %d", retryInterval, defaultRetryInterval)
		retryInterval = defaultRetryInterval
	}

	if queueSize <= 0 {
		log.Warnf("queueSize invalid: %d, replace with default value: %d", queueSize, defaultQueueSize)
		queueSize = defaultQueueSize
	}
}