Files
windows_exporter/internal/collector/textfile/utf8bom.go
T

50 lines
1.4 KiB
Go

// SPDX-License-Identifier: Apache-2.0
//
// Copyright The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package textfile
import (
"bufio"
"bytes"
"errors"
"io"
)
// skipUTF8BOM removes one leading UTF-8 BOM and rejects UTF-16/32 BOMs.
// The buffered reader is also reused by the metrics parser.
func skipUTF8BOM(r *bufio.Reader) error {
prefix, err := r.Peek(4)
if err != nil && !errors.Is(err, io.EOF) {
return err
}
switch {
case bytes.HasPrefix(prefix, []byte("\x00\x00\xfe\xff")):
return errors.New("UTF32BigEndian")
case bytes.HasPrefix(prefix, []byte("\xff\xfe\x00\x00")):
return errors.New("UTF32LittleEndian")
case bytes.HasPrefix(prefix, []byte("\xfe\xff")):
return errors.New("UTF16BigEndian")
case bytes.HasPrefix(prefix, []byte("\xff\xfe")):
return errors.New("UTF16LittleEndian")
case bytes.HasPrefix(prefix, []byte("\xef\xbb\xbf")):
_, err = r.Discard(3)
return err
default:
return nil
}
}