adding stub for decompress

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

main.go

@@ -1,7 +1,13 @@
 package main
 
 import (
+	"compress/gzip"
+	"fmt"
+	"io"
+	"math/rand"
 	"os"
+	"path/filepath"
+	"time"
 
 	"github.com/urfave/cli"
 )
@@ -78,5 +84,59 @@ func main() {
 func defaultAction(c *cli.Context) error {
 	// TODO check whether stdin or its a pty terminal, if no args
 
+	if c.Bool("decompress") {
+		if c.NArg() == 0 {
+			grdr, err := gzip.NewReader(os.Stdin)
+			if err != nil {
+				return cli.NewExitError(err, 2)
+			}
+			defer grdr.Close()
+			if _, err = io.Copy(os.Stdout, grdr); err != nil {
+				return cli.NewExitError(err, 2)
+			}
+			return nil
+		}
+
+		for _, arg := range c.Args() {
+			err := func() error {
+				fh, err := os.OpenFile(arg, os.O_RDONLY, 0600)
+				if err != nil {
+					return err
+				}
+				defer fh.Close()
+
+				fi, err := fh.Stat()
+				if err != nil {
+					return err
+				}
+
+				newName := gzBasename(c, arg)
+				newFh, err := os.OpenFile(newName, os.O_CREATE|os.O_WRONLY, fi.Mode())
+				if err != nil {
+					return err
+				}
+				defer newFh.Close()
+
+				if _, err := io.Copy(newFh, fh); err != nil {
+					return err
+				}
+
+				return nil
+			}()
+			if err != nil {
+				return cli.NewExitError(err, 2)
+			}
+		}
+
+		return nil
+	}
+
 	return nil
 }
+
+func gzBasename(c *cli.Context, s string) string {
+	if filepath.Ext(s) == c.String("suffix") {
+		return filepath.Base(s)
+	}
+	return fmt.Sprint("%s.%d", s, rand.New(rand.NewSource(time.Now().UnixNano())).Intn(100))
+}