support "-p" for postponing first run

gow_main.go

@@ -135,20 +135,25 @@ func (self *Main) WatchRun() {
 }
 
 func (self *Main) CmdRun() {
-	for {
+	if !self.Opt.Postpone {
 		self.Cmd.Restart()
+	}
 
+	for {
+	sel:
 		select {
 		case <-self.ChanRestart:
 			self.Opt.TermClear()
-			continue
+			break sel
 
 		case val := <-self.ChanKill:
 			self.Cmd.Broadcast(val)
 			self.Deinit()
 			gg.Nop1(syscall.Kill(os.Getpid(), val))
 			return
 		}
+
+		self.Cmd.Restart()
 	}
 }
 

gow_misc.go

@@ -38,6 +38,15 @@ var (
 	).Replace
 )
 
+/**
+Making `.main` private reduces the chance of accidental cyclic walking by
+reflection tools such as pretty printers.
+*/
+type Mained struct{ main *Main }
+
+func (self *Mained) Init(val *Main) { self.main = val }
+func (self *Mained) Main() *Main    { return self.main }
+
 /**
 Implemented by `notify.EventInfo`.
 Path must be an absolute filesystem path.
@@ -103,12 +112,3 @@ func withNewline[A ~string](val A) A {
 	}
 	return val + A(gg.Newline)
 }
-
-/**
-The field is private to avoid accidental cyclic walking by reflection-based
-code, not for pointless "encapsulation".
-*/
-type Mained struct{ main *Main }
-
-func (self *Mained) Init(val *Main) { self.main = val }
-func (self *Mained) Main() *Main    { return self.main }

gow_opt.go

@@ -23,7 +23,8 @@ type Opt struct {
 	Sep          FlagStrMultiline `flag:"-S"                desc:"Separator printed after each run; multi; supports \\n."`
 	Trace        bool             `flag:"-t"                desc:"Print error trace on exit. Useful for debugging gow."`
 	RawEcho      bool             `flag:"-re" init:"true"   desc:"In raw mode, echo stdin to stdout like most apps."`
-	Lazy         bool             `flag:"-l"                desc:"Lazy mode: no restart when subprocess is running."`
+	Lazy         bool             `flag:"-l"                desc:"Lazy mode: restart only when subprocess is not running."`
+	Postpone     bool             `flag:"-p"                desc:"Postpone first run until FS event or manual ^R."`
 	Extensions   FlagExtensions   `flag:"-e"  init:"go,mod" desc:"Extensions to watch; multi."`
 	Watch        FlagWatch        `flag:"-w"  init:"."      desc:"Paths to watch, relative to CWD; multi."`
 	IgnoredPaths FlagIgnoredPaths `flag:"-i"                desc:"Ignored paths, relative to CWD; multi."`

gow_stdio.go

@@ -113,13 +113,13 @@ func (self *Stdio) OnCodeSig(code byte, sig syscall.Signal, desc string) {
 	main := self.Main()
 
 	if self.IsCodeRepeated(code) {
-		log.Printf(`received %[1]v%[1]v, shutting down`, desc)
+		log.Println(`received ` + desc + desc + `, shutting down`)
 		main.Kill(sig)
 		return
 	}
 
 	if main.Opt.Verb {
-		log.Printf(`received %[1]v, stopping subprocess`, desc)
+		log.Println(`received ` + desc + `, stopping subprocess`)
 	}
 	main.Cmd.Broadcast(sig)
 }