mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-21 12:30:24 +00:00
46 lines
1.3 KiB
Go
46 lines
1.3 KiB
Go
// Copyright 2018 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.
|
|
|
|
// +build linux,!appengine
|
|
|
|
package util
|
|
|
|
import (
|
|
"bytes"
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
// SysReadFile is a simplified ioutil.ReadFile that invokes syscall.Read directly.
|
|
// https://github.com/prometheus/node_exporter/pull/728/files
|
|
func SysReadFile(file string) (string, error) {
|
|
f, err := os.Open(file)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer f.Close()
|
|
|
|
// On some machines, hwmon drivers are broken and return EAGAIN. This causes
|
|
// Go's ioutil.ReadFile implementation to poll forever.
|
|
//
|
|
// Since we either want to read data or bail immediately, do the simplest
|
|
// possible read using syscall directly.
|
|
b := make([]byte, 128)
|
|
n, err := syscall.Read(int(f.Fd()), b)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
return string(bytes.TrimSpace(b[:n])), nil
|
|
}
|