feat(expand): Add "expand" (env vars expansion) functionality (string…

…s only)

cmd/cmd.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	_ "github.com/sikalabs/slut/cmd/expand"
+	_ "github.com/sikalabs/slut/cmd/expand/string"
 	_ "github.com/sikalabs/slut/cmd/mysql"
 	_ "github.com/sikalabs/slut/cmd/mysql/create"
 	_ "github.com/sikalabs/slut/cmd/mysql/drop"

cmd/expand/expand.go

@@ -0,0 +1,15 @@
+package expand
+
+import (
+	"github.com/sikalabs/slut/cmd/root"
+	"github.com/spf13/cobra"
+)
+
+var Cmd = &cobra.Command{
+	Use:   "expand",
+	Short: "Expand environment variables in files and strings",
+}
+
+func init() {
+	root.RootCmd.AddCommand(Cmd)
+}

cmd/expand/string/string.go

@@ -0,0 +1,43 @@
+package string
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	expandcmd "github.com/sikalabs/slut/cmd/expand"
+	rootcmd "github.com/sikalabs/slut/cmd/root"
+
+	"github.com/spf13/cobra"
+)
+
+var CmdFlagSource string
+
+var Cmd = &cobra.Command{
+	Use:   "string",
+	Short: "Expand environment variables in string",
+	Args:  cobra.NoArgs,
+	Run: func(c *cobra.Command, args []string) {
+		if rootcmd.RootCmdFlagJson {
+			outJson, err := json.Marshal(os.ExpandEnv(CmdFlagSource))
+			if err != nil {
+				panic(err)
+			}
+			fmt.Println(string(outJson))
+		} else {
+			fmt.Println(os.ExpandEnv(CmdFlagSource))
+		}
+	},
+}
+
+func init() {
+	expandcmd.Cmd.AddCommand(Cmd)
+	Cmd.Flags().StringVarP(
+		&CmdFlagSource,
+		"source",
+		"s",
+		"",
+		"Source template string",
+	)
+	Cmd.MarkFlagRequired("source")
+}