| // Copyright 2022 The Android Open Source Project |
| // |
| // 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 local |
| |
| import ( |
| "bufio" |
| "bytes" |
| "context" |
| "errors" |
| "io" |
| "os/exec" |
| "time" |
| ) |
| |
| // Run the input command via pipe with given arguments, stdout of the pipe is passed to input parser |
| // argument. |
| func runPipe(ctx context.Context, timeout time.Duration, cmdName string, args []string, parser func(r io.Reader)) (err error, stdErr string) { |
| ctx, cancel := context.WithTimeout(ctx, timeout) |
| defer cancel() |
| |
| cmd := exec.CommandContext(ctx, cmdName, args[0:]...) |
| errorBuf := bytes.Buffer{} |
| cmd.Stderr = &errorBuf |
| stdout, err := cmd.StdoutPipe() |
| if err != nil { |
| return err, errorBuf.String() |
| } |
| |
| if err = cmd.Start(); err != nil { |
| return err, errorBuf.String() |
| } |
| parser(stdout) |
| if err = cmd.Wait(); err != nil { |
| return err, errorBuf.String() |
| } |
| return nil, "" |
| } |
| |
| // Run input command, stdout is passed via out parameter to user, if error the stderr is provided via |
| // stdErr string to the user. |
| func run(ctx context.Context, timeout time.Duration, cmdName string, args []string) (out *bytes.Buffer, err error, stdErr string) { |
| ctx, cancel := context.WithTimeout(ctx, timeout) |
| defer cancel() |
| |
| cmd := exec.CommandContext(ctx, cmdName, args[0:]...) |
| errorBuf := bytes.Buffer{} |
| outputBuf := bytes.Buffer{} |
| cmd.Stderr = &errorBuf |
| cmd.Stdout = &outputBuf |
| if err = cmd.Run(); err != nil { |
| return nil, err, errorBuf.String() |
| } |
| |
| return &outputBuf, nil, "" |
| } |
| |
| // lineScanner |
| // |
| // Map output lines to strings, with expected number of |
| // lines |
| type lineScanner struct { |
| Lines []string |
| } |
| |
| // Parse into lines |
| func (l *lineScanner) Parse(s *bufio.Scanner) error { |
| i := 0 |
| for s.Scan() { |
| if i < len(l.Lines) { |
| l.Lines[i] = s.Text() |
| } else { |
| i++ |
| break |
| } |
| i++ |
| } |
| if i != len(l.Lines) { |
| return errors.New("cmd: incorrect number of lines") |
| } |
| return nil |
| } |
| |
| func newLineScanner(numLines int) *lineScanner { |
| out := &lineScanner{Lines: make([]string, numLines)} |
| return (out) |
| } |