Add support for uncompressed .tar files

README.md

@@ -10,6 +10,7 @@ The `archiver` command runs the same cross-platform and has no external dependen
 Supported formats/extensions:
 
 - .zip
+- .tar
 - .tar.gz
 - .tgz
 - .tar.bz2

cmd/archiver/main.go

@@ -69,6 +69,7 @@ const usage = `Usage: archiver {make|open} <archive file> [files...]
     The format of the archive is determined by its
     file extension. Supported extensions:
       .zip
+      .tar
       .tar.gz
       .tgz
       .tar.bz2
@@ -83,10 +84,11 @@ const usage = `Usage: archiver {make|open} <archive file> [files...]
 
 var fileFormats = []struct {
 	ext     string
-	create  archiver.CompressFunc
-	extract archiver.DecompressFunc
+	create  archiver.MakeFunc
+	extract archiver.OpenFunc
 }{
 	{ext: ".zip", create: archiver.Zip, extract: archiver.Unzip},
+	{ext: ".tar", create: archiver.Tar, extract: archiver.Untar},
 	{ext: ".tar.gz", create: archiver.TarGz, extract: archiver.UntarGz},
 	{ext: ".tgz", create: archiver.TarGz, extract: archiver.UntarGz},
 	{ext: ".tar.bz2", create: archiver.TarBz2, extract: archiver.UntarBz2},

targz.go

@@ -10,11 +10,27 @@ import (
 	"strings"
 )
 
-// TarGz creates a .tar.gz file at targzPath containing
-// the contents of files listed in filePaths. File paths
-// can be those of regular files or directories. Regular
+// Tar creates a .tar file at tarPath containing the
+// contents of files listed in filePaths. File paths can
+// be those of regular files or directories. Regular
 // files are stored at the 'root' of the archive, and
 // directories are recursively added.
+func Tar(tarPath string, filePaths []string) error {
+	out, err := os.Create(tarPath)
+	if err != nil {
+		return fmt.Errorf("error creating %s: %v", tarPath, err)
+	}
+	defer out.Close()
+
+	tarWriter := tar.NewWriter(out)
+	defer tarWriter.Close()
+
+	return tarball(filePaths, tarWriter, tarPath)
+}
+
+// TarGz creates a .tar.gz file at targzPath containing
+// the contents of files listed in filePaths. It works
+// the same way Tar does, but with gzip compression.
 func TarGz(targzPath string, filePaths []string) error {
 	out, err := os.Create(targzPath)
 	if err != nil {
@@ -104,6 +120,17 @@ func tarFile(tarWriter *tar.Writer, source, dest string) error {
 	})
 }
 
+// Untar untars source and puts the contents into destination.
+func Untar(source, destination string) error {
+	f, err := os.Open(source)
+	if err != nil {
+		return fmt.Errorf("%s: failed to open archive: %v", source, err)
+	}
+	defer f.Close()
+
+	return untar(tar.NewReader(f), destination)
+}
+
 // UntarGz untars source and decompresses the contents into destination.
 func UntarGz(source, destination string) error {
 	f, err := os.Open(source)

targz_test.go

@@ -2,6 +2,10 @@ package archiver
 
 import "testing"
 
+func TestTarAndUntar(t *testing.T) {
+	symmetricTest(t, ".tar", Tar, Untar)
+}
+
 func TestTarGzAndUntarGz(t *testing.T) {
 	symmetricTest(t, ".tar.gz", TarGz, UntarGz)
 }

zip.go

@@ -211,9 +211,9 @@ var CompressedFormats = map[string]struct{}{
 }
 
 type (
-	// CompressFunc is a function that makes an archive.
-	CompressFunc func(string, []string) error
+	// MakeFunc is a function that makes an archive.
+	MakeFunc func(string, []string) error
 
-	// DecompressFunc is a function that extracts an archive.
-	DecompressFunc func(string, string) error
+	// OpenFunc is a function that extracts an archive.
+	OpenFunc func(string, string) error
 )

zip_test.go

@@ -12,7 +12,10 @@ func TestZipAndUnzip(t *testing.T) {
 	symmetricTest(t, ".zip", Zip, Unzip)
 }
 
-func symmetricTest(t *testing.T, ext string, cf CompressFunc, dcf DecompressFunc) {
+// symmetricTest performs a symmetric test by using mf to make an archive
+// from the test corpus, then using of to open the archive and comparing
+// the contents to ensure they are equal.
+func symmetricTest(t *testing.T, ext string, mf MakeFunc, of OpenFunc) {
 	tmp, err := ioutil.TempDir("", "archiver")
 	if err != nil {
 		t.Fatal(err)
@@ -21,7 +24,7 @@ func symmetricTest(t *testing.T, ext string, cf CompressFunc, dcf DecompressFunc
 
 	// Test creating archive
 	outfile := filepath.Join(tmp, "test"+ext)
-	err = cf(outfile, []string{"testdata"})
+	err = mf(outfile, []string{"testdata"})
 	if err != nil {
 		t.Fatalf("making archive: didn't expect an error, but got: %v", err)
 	}
@@ -35,7 +38,7 @@ func symmetricTest(t *testing.T, ext string, cf CompressFunc, dcf DecompressFunc
 	// Test extracting archive
 	dest := filepath.Join(tmp, "extraction_test")
 	os.Mkdir(dest, 0755)
-	err = dcf(outfile, dest)
+	err = of(outfile, dest)
 	if err != nil {
 		t.Fatalf("extracting archive: didn't expect an error, but got: %v", err)
 	}