From fd1f7665a77f3bd062586f0f3b54d4ff9863dd4b Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Wed, 21 Dec 2022 13:02:25 +0900
Subject: [PATCH] Abort fzf if --listen port is unavailable

---
 src/server.go   | 8 +++++---
 src/terminal.go | 5 ++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/server.go b/src/server.go
index eaa314c9..75af23ff 100644
--- a/src/server.go
+++ b/src/server.go
@@ -16,14 +16,14 @@ const (
 	httpBadRequest = "HTTP/1.1 400 Bad Request" + crlf
 )
 
-func startHttpServer(port int, channel chan []*action) {
+func startHttpServer(port int, channel chan []*action) error {
 	if port == 0 {
-		return
+		return nil
 	}
 
 	listener, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
 	if err != nil {
-		return
+		return fmt.Errorf("port not available: %d", port)
 	}
 
 	go func() {
@@ -41,6 +41,8 @@ func startHttpServer(port int, channel chan []*action) {
 		}
 		listener.Close()
 	}()
+
+	return nil
 }
 
 // Here we are writing a simplistic HTTP server without using net/http
diff --git a/src/terminal.go b/src/terminal.go
index 1ff40412..d0c0a9de 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -621,6 +621,10 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		t.separator, t.separatorLen = t.ansiLabelPrinter(bar, &tui.ColSeparator, true)
 	}
 
+	if err := startHttpServer(t.listenPort, t.serverChan); err != nil {
+		errorExit(err.Error())
+	}
+
 	return &t
 }
 
@@ -2500,7 +2504,6 @@ func (t *Terminal) Loop() {
 	looping := true
 	_, startEvent := t.keymap[tui.Start.AsEvent()]
 
-	startHttpServer(t.listenPort, t.serverChan)
 	eventChan := make(chan tui.Event)
 	needBarrier := true
 	barrier := make(chan bool)