archive/tar: add AddFS method to Writer

[gostls13.git] / src / archive / tar / writer.go

diff --git a/src/archive/tar/writer.go b/src/archive/tar/writer.go
index 1c95f0738a864f38aa250825e2ca05aac8a21cd1..d805e266d0594c150948b5ddfef814f91489f4ca 100644 (file)
--- a/src/archive/tar/writer.go
+++ b/src/archive/tar/writer.go
@@ -5,8 +5,10 @@
 package tar
 
 import (
+       "errors"
        "fmt"
        "io"
+       "io/fs"
        "path"
        "sort"
        "strings"
@@ -403,6 +405,43 @@ func (tw *Writer) writeRawHeader(blk *block, size int64, flag byte) error {
        return nil
 }
 
+// AddFS adds the files from fs.FS to the archive.
+// It walks the directory tree starting at the root of the filesystem
+// adding each file to the tar archive while maintaining the directory structure.
+func (tw *Writer) AddFS(fsys fs.FS) error {
+       return fs.WalkDir(fsys, ".", func(name string, d fs.DirEntry, err error) error {
+               if err != nil {
+                       return err
+               }
+               if d.IsDir() {
+                       return nil
+               }
+               info, err := d.Info()
+               if err != nil {
+                       return err
+               }
+               // TODO(#49580): Handle symlinks when fs.ReadLinkFS is available.
+               if !info.Mode().IsRegular() {
+                       return errors.New("tar: cannot add non-regular file")
+               }
+               h, err := FileInfoHeader(info, "")
+               if err != nil {
+                       return err
+               }
+               h.Name = name
+               if err := tw.WriteHeader(h); err != nil {
+                       return err
+               }
+               f, err := fsys.Open(name)
+               if err != nil {
+                       return err
+               }
+               defer f.Close()
+               _, err = io.Copy(tw, f)
+               return err
+       })
+}
+
 // splitUSTARPath splits a path according to USTAR prefix and suffix rules.
 // If the path is not splittable, then it will return ("", "", false).
 func splitUSTARPath(name string) (prefix, suffix string, ok bool) {