package main import ( "bytes" "errors" "fmt" "io" "os" "os/exec" "sync" "syscall" "hilbish/util" rt "github.com/arnodel/golua/runtime" ) var jobs *jobHandler var jobMetaKey = rt.StringValue("hshjob") type job struct { cmd string running bool id int pid int exitCode int once bool args []string // save path for a few reasons, one being security (lmao) while the other // would just be so itll be the same binary command always (path changes) path string handle *exec.Cmd cmdout io.Writer cmderr io.Writer stdout *bytes.Buffer stderr *bytes.Buffer ud *rt.UserData } func (j *job) start() error { if j.handle == nil || j.once { // cmd cant be reused so make a new one cmd := exec.Cmd{ Path: j.path, Args: j.args, } j.setHandle(&cmd) } // bgProcAttr is defined in execfile_.go, it holds a procattr struct // in a simple explanation, it makes signals from hilbish (sigint) // not go to it (child process) j.handle.SysProcAttr = bgProcAttr // reset output buffers j.stdout.Reset() j.stderr.Reset() // make cmd write to both standard output and output buffers for lua access j.handle.Stdout = io.MultiWriter(j.cmdout, j.stdout) j.handle.Stderr = io.MultiWriter(j.cmderr, j.stderr) if !j.once { j.once = true } err := j.handle.Start() proc := j.getProc() j.pid = proc.Pid j.running = true hooks.Em.Emit("job.start", rt.UserDataValue(j.ud)) return err } func (j *job) stop() { // finish will be called in exec handle proc := j.getProc() if proc != nil { proc.Kill() } } func (j *job) finish() { j.running = false hooks.Em.Emit("job.done", rt.UserDataValue(j.ud)) } func (j *job) wait() { j.handle.Wait() } func (j *job) setHandle(handle *exec.Cmd) { j.handle = handle j.args = handle.Args j.path = handle.Path if handle.Stdout != nil { j.cmdout = handle.Stdout } if handle.Stderr != nil { j.cmderr = handle.Stderr } } func (j *job) getProc() *os.Process { handle := j.handle if handle != nil { return handle.Process } return nil } func luaStartJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } j, err := jobArg(c, 0) if err != nil { return nil, err } if !j.running { err := j.start() exit := handleExecErr(err) j.exitCode = int(exit) j.finish() } return c.Next(), nil } func luaStopJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } j, err := jobArg(c, 0) if err != nil { return nil, err } if j.running { j.stop() j.finish() } return c.Next(), nil } func luaForegroundJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } j, err := jobArg(c, 0) if err != nil { return nil, err } if !j.running { return nil, errors.New("job not running") } // lua code can run in other threads and goroutines, so this exists jobs.foreground = true // this is kinda funny // background continues the process incase it got suspended err = j.background() if err != nil { return nil, err } err = j.foreground() if err != nil { return nil, err } jobs.foreground = false return c.Next(), nil } func luaBackgroundJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } j, err := jobArg(c, 0) if err != nil { return nil, err } if !j.running { return nil, errors.New("job not running") } err = j.background() if err != nil { return nil, err } return c.Next(), nil } type jobHandler struct { jobs map[int]*job latestID int foreground bool // if job currently in the foreground mu *sync.RWMutex } func newJobHandler() *jobHandler { return &jobHandler{ jobs: make(map[int]*job), latestID: 0, mu: &sync.RWMutex{}, } } func (j *jobHandler) add(cmd string, args []string, path string) *job { j.mu.Lock() defer j.mu.Unlock() j.latestID++ jb := &job{ cmd: cmd, running: false, id: j.latestID, args: args, path: path, cmdout: os.Stdout, cmderr: os.Stderr, stdout: &bytes.Buffer{}, stderr: &bytes.Buffer{}, } jb.ud = jobUserData(jb) j.jobs[j.latestID] = jb hooks.Em.Emit("job.add", rt.UserDataValue(jb.ud)) return jb } func (j *jobHandler) getLatest() *job { j.mu.RLock() defer j.mu.RUnlock() return j.jobs[j.latestID] } func (j *jobHandler) disown(id int) error { j.mu.RLock() if j.jobs[id] == nil { return errors.New("job doesnt exist") } j.mu.RUnlock() j.mu.Lock() delete(j.jobs, id) j.mu.Unlock() return nil } func (j *jobHandler) stopAll() { j.mu.RLock() defer j.mu.RUnlock() for _, jb := range j.jobs { // on exit, unix shell should send sighup to all jobs if jb.running { proc := jb.getProc() proc.Signal(syscall.SIGHUP) jb.wait() // waits for program to exit due to sighup } } } func (j *jobHandler) loader(rtm *rt.Runtime) *rt.Table { jobMethods := rt.NewTable() jFuncs := map[string]util.LuaExport{ "stop": {luaStopJob, 1, false}, "start": {luaStartJob, 1, false}, "foreground": {luaForegroundJob, 1, false}, "background": {luaBackgroundJob, 1, false}, } util.SetExports(l, jobMethods, jFuncs) jobMeta := rt.NewTable() jobIndex := func(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { j, _ := jobArg(c, 0) arg := c.Arg(1) val := jobMethods.Get(arg) if val != rt.NilValue { return c.PushingNext1(t.Runtime, val), nil } keyStr, _ := arg.TryString() switch keyStr { case "cmd": val = rt.StringValue(j.cmd) case "running": val = rt.BoolValue(j.running) case "id": val = rt.IntValue(int64(j.id)) case "pid": val = rt.IntValue(int64(j.pid)) case "exitCode": val = rt.IntValue(int64(j.exitCode)) case "stdout": val = rt.StringValue(string(j.stdout.Bytes())) case "stderr": val = rt.StringValue(string(j.stderr.Bytes())) } return c.PushingNext1(t.Runtime, val), nil } jobMeta.Set(rt.StringValue("__index"), rt.FunctionValue(rt.NewGoFunction(jobIndex, "__index", 2, false))) l.SetRegistry(jobMetaKey, rt.TableValue(jobMeta)) jobFuncs := map[string]util.LuaExport{ "all": {j.luaAllJobs, 0, false}, "last": {j.luaLastJob, 0, false}, "get": {j.luaGetJob, 1, false}, "add": {j.luaAddJob, 3, false}, "disown": {j.luaDisownJob, 1, false}, } luaJob := rt.NewTable() util.SetExports(rtm, luaJob, jobFuncs) return luaJob } func jobArg(c *rt.GoCont, arg int) (*job, error) { j, ok := valueToJob(c.Arg(arg)) if !ok { return nil, fmt.Errorf("#%d must be a job", arg + 1) } return j, nil } func valueToJob(val rt.Value) (*job, bool) { u, ok := val.TryUserData() if !ok { return nil, false } j, ok := u.Value().(*job) return j, ok } func jobUserData(j *job) *rt.UserData { jobMeta := l.Registry(jobMetaKey) return rt.NewUserData(j, jobMeta.AsTable()) } func (j *jobHandler) luaGetJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { j.mu.RLock() defer j.mu.RUnlock() if err := c.Check1Arg(); err != nil { return nil, err } jobID, err := c.IntArg(0) if err != nil { return nil, err } job := j.jobs[int(jobID)] if job == nil { return c.Next(), nil } return c.PushingNext(t.Runtime, rt.UserDataValue(job.ud)), nil } func (j *jobHandler) luaAddJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.CheckNArgs(3); err != nil { return nil, err } cmd, err := c.StringArg(0) if err != nil { return nil, err } largs, err := c.TableArg(1) if err != nil { return nil, err } execPath, err := c.StringArg(2) if err != nil { return nil, err } var args []string util.ForEach(largs, func(k rt.Value, v rt.Value) { if v.Type() == rt.StringType { args = append(args, v.AsString()) } }) jb := j.add(cmd, args, execPath) return c.PushingNext1(t.Runtime, rt.UserDataValue(jb.ud)), nil } func (j *jobHandler) luaAllJobs(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { j.mu.RLock() defer j.mu.RUnlock() jobTbl := rt.NewTable() for id, job := range j.jobs { jobTbl.Set(rt.IntValue(int64(id)), rt.UserDataValue(job.ud)) } return c.PushingNext1(t.Runtime, rt.TableValue(jobTbl)), nil } func (j *jobHandler) luaDisownJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } jobID, err := c.IntArg(0) if err != nil { return nil, err } err = j.disown(int(jobID)) if err != nil { return nil, err } return c.Next(), nil } func (j *jobHandler) luaLastJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { j.mu.RLock() defer j.mu.RUnlock() job := j.jobs[j.latestID] if job == nil { // incase we dont have any jobs yet return c.Next(), nil } return c.PushingNext1(t.Runtime, rt.UserDataValue(job.ud)), nil }