68 lines
1.8 KiB
Go
68 lines
1.8 KiB
Go
// Copyright (C) 2014 Space Monkey, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package spacelog
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import (
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"fmt"
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"os"
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"os/exec"
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)
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// CaptureOutputToFile opens a filehandle using the given path, then calls
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// CaptureOutputToFd on the associated filehandle.
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func CaptureOutputToFile(path string) error {
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fh, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0644)
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if err != nil {
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return err
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}
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defer fh.Close()
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return CaptureOutputToFd(int(fh.Fd()))
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}
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// CaptureOutputToProcess starts a process and using CaptureOutputToFd,
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// redirects stdout and stderr to the subprocess' stdin.
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// CaptureOutputToProcess expects the subcommand to last the lifetime of the
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// process, and if the subprocess dies, will panic.
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func CaptureOutputToProcess(command string, args ...string) error {
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cmd := exec.Command(command, args...)
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out, err := cmd.StdinPipe()
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if err != nil {
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return err
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}
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defer out.Close()
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type fder interface {
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Fd() uintptr
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}
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out_fder, ok := out.(fder)
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if !ok {
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return fmt.Errorf("unable to get underlying pipe")
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}
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err = CaptureOutputToFd(int(out_fder.Fd()))
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if err != nil {
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return err
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}
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err = cmd.Start()
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if err != nil {
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return err
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}
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go func() {
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err := cmd.Wait()
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if err != nil {
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panic(fmt.Errorf("captured output process died! %s", err))
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}
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}()
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return nil
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}
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