next : um next calls (um--header) and only prints the filename for piping : no more auto open

next/next.go

@@ -4,9 +4,11 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"os"
 	"os/exec"
 	"regexp"
 	"strconv"
+	"strings"
 
 	"github.com/brtholomy/um/go/cmd"
 	"github.com/brtholomy/um/go/flags"
@@ -70,30 +72,38 @@ func next(last string, desc string) (string, error) {
 	return n, nil
 }
 
-// calls (um-next) inside a running emacs server. which has the advantage of fetching the loaded
+// calls (um--header) inside a running emacs server. which has the advantage of fetching the loaded
 // value of um-date-format, and respecting any other loaded configuration we might add.
 //
 // other options would be to forego respecting Elisp config values, or loading from a common config
-// file and forcing emacs to load from there - which would be very un-Emacs. But as the file loading
+// file and forcing emacs to load from there - which would be very un-Emacs.
-// assumes a running server anyway, might as well get the current values.
 //
 // this is the point at which this design becomes weird. But I don't want to let Elisp suck this CLI
 // into its nasty grip. Go is far superior in this application and there's no way I'm writing the
 // `um tag` logic in Elisp.
 //
 // So I've got Go and and an ancient beloved Lisp machine trying to live together.
-func emacsNext(f string, tags string) error {
+func emacsHeader(f string, tags string) error {
 	quotedargs := fmt.Sprintf(`"%s"`, f)
 	if tags != "" {
 		quotedargs = fmt.Sprintf(`%s "%s"`, quotedargs, tags)
 	}
-	fn := fmt.Sprintf(`(um-next %s)`, quotedargs)
+	fn := fmt.Sprintf(`(um--header %s)`, quotedargs)
 	// NOTE: no longer get any string back from the lisp function:
-	if err := exec.Command("emacsclient", "--eval", fn).Run(); err != nil {
+	out, err := exec.Command("emacsclient", "--eval", fn).Output()
+	if err != nil {
+		return fmt.Errorf("emacsclient: %w", err)
+	}
+	// NOTE: grabbing from stdout adds a newline:
+	header := strings.TrimRight(string(out), "\n")
+	// NOTE: Unquote will convert \\n to \n and remove \":
+	header, err = strconv.Unquote(header)
+	if err != nil {
+		return fmt.Errorf("strconv.Unquote: %w", err)
+	}
+	if err := os.WriteFile(f, []byte(header), 0644); err != nil {
 		return err
 	}
-	// NOTE: sends filename to stdout for piping
-	fmt.Println(f)
 	return nil
 }
 
@@ -115,7 +125,9 @@ func Next(args []string) {
 	if err != nil {
 		log.Fatalf("um %s: %v", CMD, err)
 	}
-	if err := emacsNext(filename, opts.Tags.Val); err != nil {
+	if err := emacsHeader(filename, opts.Tags.Val); err != nil {
 		log.Fatalf("um %s: %v", CMD, err)
 	}
+	// NOTE: sends filename to stdout for piping
+	fmt.Println(filename)
 }