feat: add "run" command to invoke a compiler

this commit adds a "run" command to zvm that allows you to invoke a zig
compiler via its version name. for example: `zvm run 0.14.0 build run --help`
which is useful if you switch around projects a lot and just want to
run a single command without symlinking the version first.

README.md

@@ -33,6 +33,8 @@ like), then ZVM will update the exact executable you've called `upgrade` from.
 
 ```sh
 curl https://raw.githubusercontent.com/tristanisham/zvm/master/install.sh | bash
+# Or
+go install -ldflags "-s -w" github.com/tristanisham/zvm@latest
 ```
 
 <!-- This script will **automatically append** ZVM's required environment variables (see below) to `~/.profile` or `~/.bashrc`. -->

cli/meta/exec.go

@@ -0,0 +1,53 @@
+// Copyright 2022 Tristan Isham. All rights reserved.
+// Use of this source code is governed by the MIT
+// license that can be found in the LICENSE file.
+package meta
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+// Execute the given Zig command with a specified compiler
+func Exec(bin string, cmd []string) error {
+	// zvm run 0.14.0 build run --help
+	if bin == "" {
+		return fmt.Errorf("compiler binary cannot be empty")
+	}
+
+	zig := exec.Command(bin, cmd...)
+	zig.Stdin, zig.Stdout, zig.Stderr = os.Stdin, os.Stdout, os.Stderr
+
+	err := zig.Run()
+	if err != nil {
+		if err, ok := err.(*exec.ExitError); ok {
+			os.Exit(err.ExitCode())
+		} else {
+			return fmt.Errorf("Error executing command '%s': %s\n", cmd, err)
+		}
+	}
+
+	return nil
+}
+
+// Execute the given Zig command with a specified compiler
+// This is a convenience function that will automatically split a
+// command and execute it
+func ExecString(cmd string) error {
+	command := strings.Split(cmd, " ")
+	if len(command) < 1 {
+		return fmt.Errorf("No command given")
+	}
+
+	zig := exec.Command(command[0], command[1:]...)
+	zig.Stdin, zig.Stdout, zig.Stderr = os.Stdin, os.Stdout, os.Stderr
+
+	err := zig.Run()
+	if err != nil {
+		return fmt.Errorf("Error executing command '%s': %s\n", cmd, err)
+	}
+
+	return nil
+}

cli/run.go

@@ -0,0 +1,53 @@
+// Copyright 2022 Tristan Isham. All rights reserved.
+// Use of this source code is governed by the MIT
+// license that can be found in the LICENSE file.
+package cli
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/tristanisham/zvm/cli/meta"
+)
+
+// Run the given Zig compiler with the provided arguments
+func (z *ZVM) Run(ver string, cmd []string) error {
+	if err := z.getVersion(ver); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+
+			fmt.Printf("It looks like %s isn't installed. Would you like to install it first? [y/n]\n", ver)
+
+			if getConfirmation() {
+				if err = z.Install(ver, false); err != nil {
+					return err
+				}
+			} else {
+				return fmt.Errorf("version %s is not installed", ver)
+			}
+		}
+	}
+
+	return z.runBin(ver, cmd)
+}
+
+func (z *ZVM) runBin(ver string, cmd []string) error {
+	// $ZVM_PATH/$VERSION/zig cmd
+	bin := filepath.Join(z.baseDir, ver, "zig")
+
+	// Skip symlink checks, does this Zig binary exist?
+	stat, err := os.Stat(bin)
+	if err != nil {
+		return fmt.Errorf("%w: %s", err, stat.Name())
+	}
+
+	// the logging here really muddies up the output of the Zig compiler
+	// and adds a lot of noise. For that reason this function exits with
+	// the zig compilers exit code
+	if err := meta.Exec(bin, cmd); err != nil {
+		return err
+	}
+
+	return nil
+}

main.go

@@ -136,6 +136,22 @@ var zvmApp = &opts.App{
 				}
 			},
 		},
+		{
+			Name:  "run",
+			Usage: "run a command with the given Zig version",
+			Args:  true,
+			Flags: []opts.Flag{
+				&opts.BoolFlag{
+					Name:  "sync",
+					Usage: "sync your current version of Zig with the repository",
+				},
+			},
+			Action: func(ctx *opts.Context) error {
+				versionArg := strings.TrimPrefix(ctx.Args().First(), "v")
+				cmd := ctx.Args().Tail()
+				return zvm.Run(versionArg, cmd)
+			},
+		},
 		{
 			Name:    "list",
 			Usage:   "list installed Zig versions. Flag `--all` to see remote options",
@@ -291,18 +307,18 @@ func main() {
 
 	// run and report errors
 	if err := zvmApp.Run(os.Args); err != nil {
-// 		if meta.VERSION == "v0.7.9" && errors.Is(err, cli.ErrInvalidVersionMap) {
-// 			meta.CtaGeneric("Help", `Encountered an issue while trying to install ZLS for Zig 'master'.
-			
-// Problem: ZVM v0.7.7 and v0.7.8 may have saved an invalid 'zlsVersionMapUrl' to your settings, 
-// which causes this error. The latest version, v0.7.9, can fix this issue by using the correct URL.
-
-// To resolve this:
-// 1. Open your ZVM settings file: '~/.zvm/settings.json'
-// 2. Remove the 'zlsVersionMapUrl' key & value from the file (if present).
-// What happens next: ZVM will automatically use the correct version map the next time you run it
-// If the issue persists, please double-check your settings and try again, or create a GitHub Issue.`)
-// 		}
+		// 		if meta.VERSION == "v0.7.9" && errors.Is(err, cli.ErrInvalidVersionMap) {
+		// 			meta.CtaGeneric("Help", `Encountered an issue while trying to install ZLS for Zig 'master'.
+
+		// Problem: ZVM v0.7.7 and v0.7.8 may have saved an invalid 'zlsVersionMapUrl' to your settings,
+		// which causes this error. The latest version, v0.7.9, can fix this issue by using the correct URL.
+
+		// To resolve this:
+		// 1. Open your ZVM settings file: '~/.zvm/settings.json'
+		// 2. Remove the 'zlsVersionMapUrl' key & value from the file (if present).
+		// What happens next: ZVM will automatically use the correct version map the next time you run it
+		// If the issue persists, please double-check your settings and try again, or create a GitHub Issue.`)
+		// 		}
 		meta.CtaFatal(err)
 	}