43 lines
1.1 KiB
Go
43 lines
1.1 KiB
Go
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// Copyright (C) 2017, 2023 Opsmate, Inc.
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//
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// This Source Code Form is subject to the terms of the Mozilla
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// Public License, v. 2.0. If a copy of the MPL was not distributed
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// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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//
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// This software is distributed WITHOUT A WARRANTY OF ANY KIND.
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// See the Mozilla Public License for details.
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package monitor
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import (
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"crypto/rand"
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"encoding/hex"
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"fmt"
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"os"
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)
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func randomFileSuffix() string {
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var randomBytes [12]byte
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if _, err := rand.Read(randomBytes[:]); err != nil {
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panic(err)
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}
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return hex.EncodeToString(randomBytes[:])
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}
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func writeFile(filename string, data []byte, perm os.FileMode) error {
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tempname := filename + ".tmp." + randomFileSuffix()
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if err := os.WriteFile(tempname, data, perm); err != nil {
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return fmt.Errorf("error writing %s: %w", filename, err)
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}
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if err := os.Rename(tempname, filename); err != nil {
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os.Remove(tempname)
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return fmt.Errorf("error writing %s: %w", filename, err)
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}
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return nil
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}
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func fileExists(filename string) bool {
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_, err := os.Lstat(filename)
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return err == nil
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}
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