41 lines
771 B
Go
41 lines
771 B
Go
package ioutils
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import (
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"io"
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"io/ioutil"
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"os"
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"path/filepath"
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)
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// todo: split docker/pkg/ioutils into a separate repo
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// AtomicWriteFile atomically writes data to a file specified by filename.
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func AtomicWriteFile(filename string, data []byte, perm os.FileMode) error {
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f, err := ioutil.TempFile(filepath.Dir(filename), ".tmp-"+filepath.Base(filename))
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if err != nil {
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return err
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}
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err = os.Chmod(f.Name(), perm)
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if err != nil {
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f.Close()
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return err
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}
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n, err := f.Write(data)
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if err == nil && n < len(data) {
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f.Close()
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return io.ErrShortWrite
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}
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if err != nil {
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f.Close()
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return err
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}
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if err := f.Sync(); err != nil {
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f.Close()
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return err
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}
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if err := f.Close(); err != nil {
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return err
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}
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return os.Rename(f.Name(), filename)
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}
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