Handle config options

internal/config/file.go

@@ -0,0 +1,33 @@
+package config
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// parseFile opens the file at the given filename path, then treat each line
+// not starting with '#' as a configuration statement.
+func parseFile(o *Config, filename string) error {
+	fp, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+
+	scanner := bufio.NewScanner(fp)
+	n := 0
+	for scanner.Scan() {
+		n += 1
+		line := strings.TrimSpace(scanner.Text())
+		if len(line) > 0 && !strings.HasPrefix(line, "#") && strings.Index(line, "=") > 0 {
+			err := parseLine(o, line)
+			if err != nil {
+				return fmt.Errorf("%v:%d: error in configuration: %w", filename, n, err)
+			}
+		}
+	}
+
+	return nil
+}