Reading control file from .deb package.

debian/deb.go

@@ -0,0 +1,59 @@
+package debian
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"github.com/mkrautz/goar"
+	"io"
+	"os"
+)
+
+// GetControlFileFromDeb read control file from deb package
+func GetControlFileFromDeb(packageFile string) (Stanza, error) {
+	file, err := os.Open(packageFile)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	library := ar.NewReader(file)
+	for {
+		header, err := library.Next()
+		if err == io.EOF {
+			return nil, fmt.Errorf("unable to find control.tar.gz part")
+		}
+		if err != nil {
+			return nil, fmt.Errorf("unable to read .deb archive: %s", err)
+		}
+
+		if header.Name == "control.tar.gz" {
+			ungzip, err := gzip.NewReader(library)
+			if err != nil {
+				return nil, fmt.Errorf("unable to ungzip: %s", err)
+			}
+			defer ungzip.Close()
+
+			untar := tar.NewReader(ungzip)
+			for {
+				tarHeader, err := untar.Next()
+				if err == io.EOF {
+					return nil, fmt.Errorf("unable to find control file")
+				}
+				if err != nil {
+					return nil, fmt.Errorf("unable to read .tar archive: %s", err)
+				}
+
+				if tarHeader.Name == "./control" {
+					reader := NewControlFileReader(untar)
+					stanza, err := reader.ReadStanza()
+					if err != nil {
+						return nil, err
+					}
+
+					return stanza, nil
+				}
+			}
+		}
+	}
+}