ggman clone: Allow using native 'git'

README.md

@@ -175,7 +175,7 @@ This page includes releases for Linux, Mac OS X and Windows.
 Note that these binaries are compressed with [`upx`](https://upx.github.io) in order to decrease executable size. 
 
 After obtaining the binary (through either of the two means), simply place it in your `$PATH`. 
-`ggman` does not depend on any external software (no need for `git` even). 
+`ggman` does not depend on any external software (although having `git` in `$PATH` allows for passing through arguments to `clone`). 
 
 ## LICENSE
 

src/commands/clone.go

@@ -30,5 +30,5 @@ func CloneCommand(runtime *program.SubRuntime) (retval int, err string) {
 	targetPath := path.Join(append([]string{root}, remote.Components()...)...)
 
 	// and finish
-	return gitwrap.CloneRepository(cloneURI, targetPath)
+	return gitwrap.CloneRepository(cloneURI, targetPath, argv[1:]...)
 }

src/constants/usage.go

@@ -19,7 +19,7 @@ const StringSimulateFlagUsage string = "If set, only print what would be done. "
 const StringCompsURIUsage string = "Repository URI to print components of. "
 
 // StringCloneURIUsage represents  the Clone URI usage string
-const StringCloneURIUsage string = "URI of repository to clone. "
+const StringCloneURIUsage string = "URI of repository to clone and arguments to pass to 'git clone'"
 
 // StringLinkPathUsage represents  the Link PATH usage string
 const StringLinkPathUsage string = "Path of repository to symlink. "

src/gitwrap/clone.go

@@ -1,15 +1,17 @@
 package gitwrap
 
 import (
+	"errors"
 	"fmt"
 	"os"
+	"os/exec"
 
 	"github.com/tkw1536/ggman/src/constants"
 	git "gopkg.in/src-d/go-git.v4"
 )
 
 // CloneRepository clones a repository into a given location
-func CloneRepository(from string, to string) (retval int, err string) {
+func CloneRepository(from string, to string, args ...string) (retval int, err string) {
 	// tell the user what we are doing
 	fmt.Printf("Cloning %q into %q ...\n", from, to)
 
@@ -27,8 +29,7 @@ func CloneRepository(from string, to string) (retval int, err string) {
 		return
 	}
 
-	// do the clone
-	if _, e := git.PlainClone(to, false, &git.CloneOptions{URL: from, Progress: os.Stdout}); e != nil {
+	if e := cloneRepositorySmart(from, to, args...); e != nil {
 		err = e.Error()
 		retval = constants.ErrorCodeCustom
 		return
@@ -37,3 +38,40 @@ func CloneRepository(from string, to string) (retval int, err string) {
 	// and be done
 	return
 }
+
+// clones a repository either internally or externally
+func cloneRepositorySmart(from string, to string, args ...string) error {
+	if hasExternalGit() {
+		return cloneRepositoryExternal(from, to, args...)
+	} else if len(args) != 0 {
+		return errors.New("External 'git' not found, can not pass any additional arguments to 'git clone'. ")
+	} else {
+		return cloneRepositoryInternal(from, to)
+	}
+}
+
+// checks if we have an external git in $PATH
+func hasExternalGit() bool {
+	_, err := exec.LookPath("git")
+	return err == nil
+}
+
+// clones a repository using the built-in git
+func cloneRepositoryInternal(from string, to string) error {
+	_, e := git.PlainClone(to, false, &git.CloneOptions{URL: from, Progress: os.Stdout})
+	return e
+}
+
+// clones a repository using an external 'git' command
+func cloneRepositoryExternal(from string, to string, args ...string) error {
+	gargs := append([]string{"clone", from, to}, args...)
+	cmd := exec.Command("git", gargs...)
+
+	cmd.Dir = to
+
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}

src/main.go

@@ -30,7 +30,7 @@ func Main(argv []string) (retval int, err string) {
 
 	ggman.Register("fix", commands.FixCommand, &program.SubOptions{ForArgument: program.OptionalFor, Flag: "--simulate", UsageDescription: constants.StringSimulateFlagUsage, NeedsRoot: true, NeedsCANFILE: true})
 
-	ggman.Register("clone", commands.CloneCommand, &program.SubOptions{MinArgs: 1, MaxArgs: 1, Metavar: "URI", UsageDescription: constants.StringCloneURIUsage, NeedsRoot: true, NeedsCANFILE: true})
+	ggman.Register("clone", commands.CloneCommand, &program.SubOptions{MinArgs: 1, MaxArgs: -1, Metavar: "ARG", UsageDescription: constants.StringCloneURIUsage, NeedsRoot: true, NeedsCANFILE: true})
 	ggman.Register("link", commands.LinkCommand, &program.SubOptions{MinArgs: 1, MaxArgs: 1, Metavar: "PATH", UsageDescription: constants.StringLinkPathUsage, NeedsRoot: true})
 
 	ggman.Register("license", commands.LicenseCommand, &program.SubOptions{})

src/program/runtime.go

@@ -84,10 +84,16 @@ func (opt *SubOptions) Usage(name string) (usage string) {
 			mv = "ARGUMENT"
 		}
 
-		// write out the argument an appropriate number of times
-		flagString += strings.Repeat(" "+mv, opt.MinArgs)
-		flagString += strings.Repeat(" ["+mv, opt.MaxArgs-opt.MinArgs)
-		flagString += strings.Repeat("]", opt.MaxArgs-opt.MinArgs)
+		if opt.MaxArgs == -1 {
+			// write out the argument an appropriate number of times
+			flagString += strings.Repeat(" "+mv, opt.MinArgs)
+			flagString += " [" + mv + " ... ]"
+		} else {
+			// write out the argument an appropriate number of times
+			flagString += strings.Repeat(" "+mv, opt.MinArgs)
+			flagString += strings.Repeat(" ["+mv, opt.MaxArgs-opt.MinArgs)
+			flagString += strings.Repeat("]", opt.MaxArgs-opt.MinArgs)
+		}
 	}
 
 	usage += flagString