| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package modules |
| |
| import ( |
| "flag" |
| "fmt" |
| "hash/adler32" |
| "io" |
| "io/ioutil" |
| "os" |
| "strings" |
| |
| "v.io/v23/security" |
| "v.io/x/lib/vlog" |
| vsecurity "v.io/x/ref/lib/security" |
| ) |
| |
| func newLogfile(prefix, name string) (*os.File, error) { |
| nameHash := adler32.Checksum([]byte(name)) |
| f, err := ioutil.TempFile("", fmt.Sprintf("__modules__%s-%x-", prefix, nameHash)) |
| if err != nil { |
| return nil, err |
| } |
| return f, nil |
| } |
| |
| func outputFromFile(f *os.File, out io.Writer) { |
| f.Close() |
| fName := f.Name() |
| defer os.Remove(fName) |
| if out == nil { |
| return |
| } |
| var err error |
| if f, err = os.Open(fName); err != nil { |
| vlog.VI(1).Infof("failed to open %q: %s\n", fName, err) |
| return |
| } |
| io.Copy(out, f) |
| f.Close() |
| } |
| |
| func principalFromDir(dir string) (security.Principal, error) { |
| p, err := vsecurity.LoadPersistentPrincipal(dir, nil) |
| if err == nil { |
| return p, nil |
| } |
| if !os.IsNotExist(err) { |
| return nil, err |
| } |
| p, err = vsecurity.CreatePersistentPrincipal(dir, nil) |
| if err != nil { |
| return nil, err |
| } |
| if err := vsecurity.InitDefaultBlessings(p, shellBlessingExtension); err != nil { |
| return nil, err |
| } |
| return p, nil |
| } |
| |
| // Usage generates a usage string based on the flags in a flagset. |
| func Usage(fs *flag.FlagSet) string { |
| res := []string{} |
| fs.VisitAll(func(f *flag.Flag) { |
| format := " -%s=%s: %s" |
| if getter, ok := f.Value.(flag.Getter); ok { |
| if _, ok := getter.Get().(string); ok { |
| // put quotes on the value |
| format = " -%s=%q: %s" |
| } |
| } |
| res = append(res, fmt.Sprintf(format, f.Name, f.DefValue, f.Usage)) |
| }) |
| return strings.Join(res, "\n") + "\n" |
| } |