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
+				}
+			}
+		}
+	}
+}

debian/deb_test.go

@@ -0,0 +1,32 @@
+package debian
+
+import (
+	. "launchpad.net/gocheck"
+	"path/filepath"
+	"runtime"
+)
+
+type DebSuite struct {
+	debFile string
+}
+
+var _ = Suite(&DebSuite{})
+
+func (s *DebSuite) SetUpSuite(c *C) {
+	_, __file__, _, _ := runtime.Caller(0)
+	s.debFile = filepath.Join(filepath.Dir(__file__), "../system/files/libboost-program-options-dev_1.49.0.1_i386.deb")
+}
+
+func (s *DebSuite) TestGetControlFileFromDeb(c *C) {
+	_, err := GetControlFileFromDeb("/no/such/file")
+	c.Check(err, ErrorMatches, ".*no such file or directory")
+
+	_, __file__, _, _ := runtime.Caller(0)
+	_, err = GetControlFileFromDeb(__file__)
+	c.Check(err, ErrorMatches, "unable to read .deb archive: ar: missing global header")
+
+	st, err := GetControlFileFromDeb(s.debFile)
+	c.Check(err, IsNil)
+	c.Check(st["Version"], Equals, "1.49.0.1")
+	c.Check(st["Package"], Equals, "libboost-program-options-dev")
+}