Support plumb arguments to editinacme

.gitignore

@@ -0,0 +1,9 @@
+# binaries
+/editinacme
+
+# clutter
+.DS_Store
+.localized
+
+# Everybody has their own so don't check in by accident.
+guide

acme/editinacme/main.go

@@ -6,26 +6,34 @@
 //
 // Usage:
 //
-//	editinacme <file>
+//	editinacme [-nw] <file>
 //
-// Editinacme uses the plumber to ask acme to open the file,
-// waits until the file's acme window is deleted, and exits.
+// Editinacme uses the plumber to ask acme to open the file, waits until
+// the file's acme window is deleted, and exits. Use the -nw flag to exit
+// immediately after opening the file.
 package main
 
 import (
+	"bufio"
 	"flag"
 	"fmt"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 
 	"9fans.net/go/acme"
+	"9fans.net/go/plan9"
+	"9fans.net/go/plumb"
 )
 
 func main() {
 	log.SetFlags(0)
 	log.SetPrefix("editinacme: ")
+
+	nowait := flag.Bool("nw", false, "Don't wait for Acme to close the file")
+
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "usage: editinacme file\n")
 		os.Exit(2)
@@ -47,21 +55,61 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer r.Close()
 
-	log.Printf("editing %s", file)
+	filenamechan := make(chan string)
+	if !*nowait {
+		fid, err := plumb.Open("edit", plan9.OREAD)
+		if err != nil {
+			log.Fatalf("can't open plumber: %v", err)
+		}
+		defer fid.Close()
+		brd := bufio.NewReader(fid)
+		m := new(plumb.Message)
+
+		go func() {
+			for {
+				err := m.Recv(brd)
+				if err != nil {
+					log.Fatalf("recv: %s", err)
+				}
+				if filename, likelymy := likelymyplumbrequest(m, file); likelymy {
+					filenamechan <- filename
+					return
+				}
+			}
+		}()
+	}
 
+	log.Printf("editing %s", file)
 	out, err := exec.Command("plumb", "-d", "edit", file).CombinedOutput()
 	if err != nil {
 		log.Fatalf("executing plumb: %v\n%s", err, out)
 	}
 
-	for {
-		ev, err := r.Read()
-		if err != nil {
-			log.Fatalf("reading acme log: %v", err)
-		}
-		if ev.Op == "del" && ev.Name == file {
-			break
+	if !*nowait {
+		filename := <-filenamechan
+		for {
+			ev, err := r.Read()
+			if err != nil {
+				log.Fatalf("reading acme log: %v", err)
+			}
+			if ev.Op == "del" && ev.Name == filename {
+				break
+			}
 		}
 	}
 }
+
+// likelymyplumbrequest applies some heuristics to determine if this
+// message likely corresponds to the just made plumb edit request and
+// returns the filename that the plumber asked Acme to open.
+func likelymyplumbrequest(msg *plumb.Message, arg string) (string, bool) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		log.Fatalf("aww shucks! %v", err)
+	}
+	plumbedfname := string(msg.Data)
+	myreq := (msg.Dir == cwd && strings.HasPrefix(arg, plumbedfname))
+	return plumbedfname, myreq
+}