I believe that all functionality is implemented

cmd/config.go

@@ -7,6 +7,7 @@ package cmd
 import (
 	"fmt"
 	"sort"
+	"strings"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -15,8 +16,11 @@ import (
 // configCmd represents the config command
 var configCmd = &cobra.Command{
 	Use:   "config",
-	Short: "Print all configuration values",
-	RunE:  opConfig,
+	Short: "Show or update configuration values",
+	Long: `To set values just list them in key=value format.
+	For example: 
+		gime config copytags=true roundto=30m`,
+	RunE: opConfig,
 }
 
 func init() {
@@ -24,9 +28,36 @@ func init() {
 }
 
 func opConfig(cmd *cobra.Command, args []string) error {
+	updConfig := make(map[string]string)
+	if len(args) > 0 {
+		// We're setting arguments
+		for _, a := range args {
+			pts := strings.Split(a, "=")
+			if len(pts) == 2 {
+				updConfig[pts[0]] = pts[1]
+			} else {
+				return fmt.Errorf("Unable to parse config values.")
+			}
+		}
+	}
 	var settings []string
 	for k, v := range viper.AllSettings() {
-		settings = append(settings, fmt.Sprintf("%s: %s", k, v))
+		switch v.(type) {
+		case bool:
+			if nv, ok := updConfig[k]; ok {
+				v = nv == "true"
+				viper.Set(k, v)
+				viper.WriteConfig()
+			}
+			settings = append(settings, fmt.Sprintf("%s: %t", k, v))
+		default:
+			if nv, ok := updConfig[k]; ok {
+				v = nv
+				viper.Set(k, v)
+				viper.WriteConfig()
+			}
+			settings = append(settings, fmt.Sprintf("%s: %s", k, v))
+		}
 	}
 	sort.Strings(settings)
 	fmt.Println("Configuration File:", viper.ConfigFileUsed())