allow {cmd}_{os}_{arch} name for executable in asset (#19)

selfupdate/uncompress.go

@@ -10,9 +10,32 @@ import (
 	"io"
 	"io/ioutil"
 	"path/filepath"
+	"runtime"
 	"strings"
 )
 
+func matchExecutableName(cmd, target string) bool {
+	if cmd == target {
+		return true
+	}
+
+	o, a := runtime.GOOS, runtime.GOARCH
+
+	// When the contained executable name is full name (e.g. foo_darwin_amd64),
+	// it is also regarded as a target executable file. (#19)
+	for _, d := range []rune{'_', '-'} {
+		c := fmt.Sprintf("%s%c%s%c%s", cmd, d, o, d, a)
+		if o == "windows" {
+			c += ".exe"
+		}
+		if c == target {
+			return true
+		}
+	}
+
+	return false
+}
+
 func unarchiveTar(src io.Reader, url, cmd string) (io.Reader, error) {
 	t := tar.NewReader(src)
 	for {
@@ -24,7 +47,7 @@ func unarchiveTar(src io.Reader, url, cmd string) (io.Reader, error) {
 			return nil, fmt.Errorf("Failed to unarchive .tar file: %s", err)
 		}
 		_, name := filepath.Split(h.Name)
-		if name == cmd {
+		if matchExecutableName(cmd, name) {
 			log.Println("Executable file", h.Name, "was found in tar archive")
 			return t, nil
 		}
@@ -56,7 +79,7 @@ func UncompressCommand(src io.Reader, url, cmd string) (io.Reader, error) {
 
 		for _, file := range z.File {
 			_, name := filepath.Split(file.Name)
-			if !file.FileInfo().IsDir() && name == cmd {
+			if !file.FileInfo().IsDir() && matchExecutableName(cmd, name) {
 				log.Println("Executable file", file.Name, "was found in zip archive")
 				return file.Open()
 			}
@@ -81,7 +104,7 @@ func UncompressCommand(src io.Reader, url, cmd string) (io.Reader, error) {
 		}
 
 		name := r.Header.Name
-		if name != cmd {
+		if !matchExecutableName(cmd, name) {
 			return nil, fmt.Errorf("File name '%s' does not match to command '%s' found in %s", name, cmd, url)
 		}
 
@@ -103,6 +126,7 @@ func UncompressCommand(src io.Reader, url, cmd string) (io.Reader, error) {
 		if err != nil {
 			return nil, fmt.Errorf("Failed to uncompress xzip file downloaded from %s: %s", url, err)
 		}
+
 		log.Println("Uncompressed file from xzip is assumed to be an executable", cmd)
 		return xzip, nil
 	}