diff options
Diffstat (limited to 'run.go')
| -rw-r--r-- | run.go | 179 |
1 files changed, 179 insertions, 0 deletions
@@ -0,0 +1,179 @@ +package shell + +import "strings" +import "time" +import "os/exec" +import "bytes" +import "io" +import "fmt" +import "os" +import "bufio" +import "github.com/svent/go-nbreader" + +import "git.wit.com/wit/log" + +var msecDelay int = 20 // check every 20 milliseconds + +// TODO: look at https://github.com/go-cmd/cmd/issues/20 +// use go-cmd instead here? +// exiterr.Sys().(syscall.WaitStatus) + +// var newfile *shell.File + +func Run(cmdline string) string { + test := New() + test.Exec(cmdline) + return Chomp(test.Buffer) +} + +func (cmd *Shell) Run(cmdline string) string { + cmd.InitProcess(cmdline) + if (cmd.Error != nil) { + return "" + } + cmd.Exec(cmdline) + return Chomp(cmd.Buffer) +} + +func (cmd *Shell) InitProcess(cmdline string) { + log.Println("shell.InitProcess() START " + cmdline) + + cmd.Cmdline = Chomp(cmdline) // this is like 'chomp' in perl + cmdArgs := strings.Fields(cmd.Cmdline) + if (len(cmdArgs) == 0) { + cmd.Error = fmt.Errorf("cmdline == ''") + cmd.Done = true + return + } + if (cmdArgs[0] == "cd") { + if (len(cmdArgs) > 1) { + log.Println("os.Chdir()", cmd) + os.Chdir(cmdArgs[1]) + } + handleError(nil, 0) + cmd.Done = true + return + } + + cmd.Process = exec.Command(cmdArgs[0], cmdArgs[1:len(cmdArgs)]...) +} + +func (cmd *Shell) FileCreate(out string) { + var newfile File + + var iof io.ReadCloser + if (out == "STDOUT") { + iof, _ = cmd.Process.StdoutPipe() + } else { + iof, _ = cmd.Process.StderrPipe() + } + + newfile.Fio = iof + newfile.Fbufio = bufio.NewReader(iof) + newfile.Fnbreader = nbreader.NewNBReader(newfile.Fbufio, 1024) + + if (out == "STDOUT") { + cmd.STDOUT = &newfile + } else { + cmd.STDERR = &newfile + } +} + +// NOTE: this might cause problems: +// always remove the newlines at the end ? +func (cmd *Shell) Exec(cmdline string) { + log.Println("shell.Run() START " + cmdline) + + cmd.InitProcess(cmdline) + if (cmd.Error != nil) { + return + } + + cmd.FileCreate("STDOUT") + cmd.FileCreate("STDERR") + + cmd.Process.Start() + + // TODO; 'goroutine' both of these + // and make your own wait that will make sure + // the process is then done and run process.Wait() + go cmd.Capture(cmd.STDERR) + cmd.Capture(cmd.STDOUT) + + // wait until the process exists + // https://golang.org/pkg/os/exec/#Cmd.Wait + // What should happen here, before calling Wait() + // is checks to make sure the READERS() on STDOUT and STDERR are done + err := cmd.Process.Wait() + + // time.Sleep(2 * time.Second) // putting this here doesn't help STDOUT flush() + + if (err != nil) { + cmd.Error = err + log.Println("process.Wait() END err =", err.Error()) + } else { + log.Println("process.Wait() END") + } + return +} + +func (cmd *Shell) Capture(f *File) { + log.Debugln("nbrREADER() START") + + if (cmd.Buffer == nil) { + cmd.Buffer = new(bytes.Buffer) + } + if (cmd.Buffer == nil) { + log.Debugln("f.Buffer == nil") + log.Debugln("SHOULD DIE HERE") + f.Dead = false + cmd.Error = fmt.Errorf("could not make buffer") + cmd.Done = true + } + + f.Dead = false + + // loop that keeps trying to read from f + for (f.Dead == false) { + time.Sleep(time.Duration(msecDelay) * time.Millisecond) // only check the buffer 500 times a second + + // set to false so it keeps retrying reads + f.Empty = false + + // tight loop that reads 1024 bytes at a time until buffer is empty + // 1024 is set in f.BufferSize + for (f.Empty == false) { + f.Empty = cmd.ReadToBuffer(f) + } + } +} + +// returns true if filehandle buffer is empty +func (cmd *Shell) ReadToBuffer(f *File) bool { + // log.Debugln("ReadToBuffer() START") + nbr := f.Fnbreader + oneByte := make([]byte, 1024) + if (nbr == nil) { + // log.Debugln("ReadToBuffer() ERROR nbr is nil") + f.Dead = true + return true + } + count, err := nbr.Read(oneByte) + f.TotalCount += count + + if (err != nil) { + // log.Debugln("ReadToBuffer() file has closed with", err) + // log.Debugln("ReadToBuffer() count = ", count, "err = ", err) + f.Dead = true + return true + } + if (count == 0) { + // log.Debugln("ReadToBuffer() START count == 0 return true") + return true + } + // log.Debugln("ReadToBuffer() count = ", count) + // tmp := Chomp(oneByte) + // log.Debugln("ReadToBuffer() tmp = ", tmp) + io.WriteString(cmd.Buffer, string(oneByte)) + return false +} |