Add helper command

helper.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"os"
+
+	"github.com/urfave/cli/v2"
+	"lure.sh/lure/internal/shutils/helpers"
+	"lure.sh/lure/pkg/loggerctx"
+	"mvdan.cc/sh/v3/expand"
+	"mvdan.cc/sh/v3/interp"
+)
+
+var helperCmd = &cli.Command{
+	Name:  "helper",
+	Usage: "Run a lure helper command",
+	Flags: []cli.Flag{
+		&cli.StringFlag{
+			Name:    "dest-dir",
+			Aliases: []string{"d"},
+			Usage:   "The directory that the install commands will install to",
+			Value:   "dest",
+		},
+	},
+	Action: func(c *cli.Context) error {
+		ctx := c.Context
+		log := loggerctx.From(ctx)
+
+		wd, err := os.Getwd()
+		if err != nil {
+			log.Fatal("Error getting working directory").Err(err).Send()
+		}
+
+		helper, ok := helpers.Helpers[c.Args().First()]
+		if !ok {
+			log.Fatal("No such helper command").Str("handler", c.Args().First()).Send()
+		}
+
+		hc := interp.HandlerContext{
+			Env:    expand.ListEnviron("pkgdir=" + c.String("dest-dir")),
+			Dir:    wd,
+			Stdin:  os.Stdin,
+			Stdout: os.Stdout,
+			Stderr: os.Stderr,
+		}
+
+		return helper(hc, c.Args().First(), c.Args().Slice()[1:])
+	},
+}

main.go

@@ -63,13 +63,22 @@ var app = &cli.App{
 		refreshCmd,
 		fixCmd,
 		versionCmd,
+		helperCmd,
 	},
 	Before: func(c *cli.Context) error {
-		args := strings.Split(c.String("pm-args"), " ")
-		if len(args) == 1 && args[0] == "" {
-			return nil
+		ctx := c.Context
+		log := loggerctx.From(ctx)
+
+		cmd := c.Args().First()
+		if cmd != "helper" && !config.Config(ctx).Unsafe.AllowRunAsRoot && os.Geteuid() == 0 {
+			log.Fatal("Running LURE as root is forbidden as it may cause catastrophic damage to your system").Send()
 		}
-		manager.Args = append(manager.Args, args...)
+
+		if trimmed := strings.TrimSpace(c.String("pm-args")); trimmed != "" {
+			args := strings.Split(trimmed, " ")
+			manager.Args = append(manager.Args, args...)
+		}
+
 		return nil
 	},
 	After: func(ctx *cli.Context) error {
@@ -92,10 +101,6 @@ func main() {
 	log := translations.NewLogger(ctx, logger.NewCLI(os.Stderr), config.Language(ctx))
 	ctx = loggerctx.With(ctx, log)
 
-	if !config.Config(ctx).Unsafe.AllowRunAsRoot && os.Geteuid() == 0 {
-		log.Fatal("Running LURE as root is forbidden as it may cause catastrophic damage to your system").Send()
-	}
-
 	// Set the root command to the one set in the LURE config
 	manager.DefaultRootCmd = config.Config(ctx).RootCmd