14745: Improves azure driver exported var comment

[arvados.git] / lib / cmd / cmd.go

diff --git a/lib/cmd/cmd.go b/lib/cmd/cmd.go
index 2cc71e68a8e749e76d558b6c98e9e2c26a23f2db..9292ef7e5ff5b3afb6012833299d9f89a7ea346c 100644 (file)
--- a/lib/cmd/cmd.go
+++ b/lib/cmd/cmd.go
@@ -11,6 +11,9 @@ import (
        "fmt"
        "io"
        "io/ioutil"
+       "path/filepath"
+       "regexp"
+       "runtime"
        "sort"
        "strings"
 )
@@ -25,8 +28,17 @@ func (f HandlerFunc) RunCommand(prog string, args []string, stdin io.Reader, std
        return f(prog, args, stdin, stdout, stderr)
 }
 
-// Multi is a Handler that looks up its first argument in a map, and
-// invokes the resulting Handler with the remaining args.
+type Version string
+
+func (v Version) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
+       prog = regexp.MustCompile(` -*version$`).ReplaceAllLiteralString(prog, "")
+       fmt.Fprintf(stdout, "%s %s (%s)\n", prog, v, runtime.Version())
+       return 0
+}
+
+// Multi is a Handler that looks up its first argument in a map (after
+// stripping any "arvados-" or "crunch-" prefix), and invokes the
+// resulting Handler with the remaining args.
 //
 // Example:
 //
@@ -41,17 +53,21 @@ func (f HandlerFunc) RunCommand(prog string, args []string, stdin io.Reader, std
 type Multi map[string]Handler
 
 func (m Multi) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
-       if len(args) < 1 {
+       _, basename := filepath.Split(prog)
+       basename = strings.TrimPrefix(basename, "arvados-")
+       basename = strings.TrimPrefix(basename, "crunch-")
+       if cmd, ok := m[basename]; ok {
+               return cmd.RunCommand(prog, args, stdin, stdout, stderr)
+       } else if len(args) < 1 {
                fmt.Fprintf(stderr, "usage: %s command [args]\n", prog)
                m.Usage(stderr)
                return 2
-       }
-       if cmd, ok := m[args[0]]; !ok {
-               fmt.Fprintf(stderr, "unrecognized command %q\n", args[0])
+       } else if cmd, ok = m[args[0]]; ok {
+               return cmd.RunCommand(prog+" "+args[0], args[1:], stdin, stdout, stderr)
+       } else {
+               fmt.Fprintf(stderr, "%s: unrecognized command %q\n", prog, args[0])
                m.Usage(stderr)
                return 2
-       } else {
-               return cmd.RunCommand(prog+" "+args[0], args[1:], stdin, stdout, stderr)
        }
 }