Adds pm ls

cmd/pm/main.go

@@ -23,6 +23,7 @@ subcommands:
   environ    (env) -- print environment information
   install    (in)  -- install packages
   keyring    (key) -- interact with pm's OpenPGP keyring
+  ls               -- list installed packages
   package    (pkg) -- create packages
   pull             -- fetch all available packages from all configured remotes
   remote           -- configure remote pmd servers
@@ -232,6 +233,10 @@ func main() {
 		if err := pkg.Install(root, pkgs); err != nil {
 			fatalf("installing: %v\n", err)
 		}
+	case "ls":
+		if err := db.ListInstalled(root, os.Stdout); err != nil {
+			fatalf("listing installed: %v\n", err)
+		}
 	case "version", "v":
 		fmt.Printf("pm: version %v\n", Version)
 	default:

db/installed.go

@@ -2,6 +2,8 @@ package db
 
 import (
 	"encoding/json"
+	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 
@@ -33,6 +35,19 @@ func IsInstalled(root string, m pm.Meta) (bool, error) {
 	return r, nil
 }
 
+// ListInstalled pretty prints the installed database to w.
+func ListInstalled(root string, w io.Writer) error {
+	db, err := loadi(root)
+	if err != nil {
+		return errors.Wrap(err, "loading installed db")
+	}
+
+	for m := range db.Traverse() {
+		fmt.Fprintf(w, "%v\t%v\t%v\n", m.Name, m.Version, m.Remote.String())
+	}
+	return nil
+}
+
 func loadi(root string) (pm.Installed, error) {
 	r := pm.Installed{}
 	dbn := filepath.Join(root, in)

installed.go

@@ -1,4 +1,24 @@
 package pm
 
+import "sort"
+
 // Installed tracks installed packages.
 type Installed map[Name]Meta
+
+// Traverse returns a chan of Meta that will be sanely sorted.
+func (i Installed) Traverse() <-chan Meta {
+	r := make(chan Meta)
+	go func() {
+		names := Names{}
+		for n := range i {
+			names = append(names, n)
+		}
+		sort.Sort(names)
+
+		for _, n := range names {
+			r <- i[n]
+		}
+		close(r)
+	}()
+	return r
+}