forked from cockroachdb/cockroach
/
stderr_redirect.go
48 lines (41 loc) · 1.34 KB
/
stderr_redirect.go
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// Copyright 2017 The Cockroach 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 log
import (
"os"
)
// OrigStderr points to the original stderr stream.
var OrigStderr = func() *os.File {
fd, err := dupFD(os.Stderr.Fd())
if err != nil {
panic(err)
}
return os.NewFile(fd, os.Stderr.Name())
}()
// stderrRedirected attempts to track whether stderr was redirected.
// This is used to de-duplicate the panic log.
var stderrRedirected bool
// hijackStderr replaces stderr with the given file descriptor.
//
// A client that wishes to use the original stderr must use
// OrigStderr defined above.
func hijackStderr(f *os.File) error {
stderrRedirected = true
return redirectStderr(f)
}
// restoreStderr cancels the effect of hijackStderr().
func restoreStderr() error {
stderrRedirected = false
return redirectStderr(OrigStderr)
}