From a8d430407686fd2da11d79db0ceccbb02335d131 Mon Sep 17 00:00:00 2001
From: Tilman Kranz <kranz@b1-systems.de>
Date: Fri, 23 May 2025 22:06:38 +0200
Subject: [PATCH] better ssh status and commandline error checking

---
 pulseaudio-tcp | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/pulseaudio-tcp b/pulseaudio-tcp
index 1f52279..3fbdb7c 100644
--- a/pulseaudio-tcp
+++ b/pulseaudio-tcp
@@ -71,7 +71,7 @@ debug() {
 }
 
 _ssh() {
-    if ssh -S "$USER"-pulseaudio "$remote_user"@"$remote_ip" "$@" ; then
+    if ssh -o PasswordAuthentication=no -S "$USER"-pulseaudio "$remote_user"@"$remote_ip" "$@" ; then
         return 0
     else
         error "SSH remote_ip=$remote_ip failed."
@@ -79,6 +79,15 @@ _ssh() {
     fi
 }
 
+_scp() {
+    if scp -o PasswordAuthentication=no -q "$1" "$2" ; then
+        return 0
+    else
+        error "SCP $1 $2 failed"
+        return 1
+    fi
+}
+
 question_yesno() {
     question=$*
 
@@ -204,7 +213,7 @@ EOF
 # Check if SSH port forwarding is running
 check_pa_ssh() {
     for pid in $(pidof ssh) ; do
-        if grep -Fq "$USER"-pulseaudio /proc/"$pid"/cmdline && grep -Fq -e -L /proc/"$pid"/cmdline ; then
+        if grep -Fbq "$USER"-pulseaudio /proc/"$pid"/cmdline && grep -Fbq -e -L /proc/"$pid"/cmdline ; then
             return 0
         fi
     done
@@ -256,7 +265,7 @@ do_status() {
 
 # Acquire PulseAudio cookie from remote host
 sync_pa_cookie() {
-    if scp -q "$remote_user"@"$remote_ip":.config/pulse/cookie ~/.config/pulse/cookie ; then
+    if _scp "$remote_user"@"$remote_ip":.config/pulse/cookie ~/.config/pulse/cookie ; then
         debug "Synced PulseAudio cookie from remote host $remote_ip."
         return 0
     else
@@ -267,7 +276,11 @@ sync_pa_cookie() {
 
 # Establish SSH port forwarding to PulseAudio TCP server on remote host
 establish_ssh_portforward() {
-    _ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713
+    if check_pa_ssh ; then
+        debug "Not establishing SSH forwarding (already running)"
+    else
+        _ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713
+    fi
 }
 
 # Enable PulseAudio TCP tunnel server on remote host
@@ -433,6 +446,8 @@ do_stop() {
 ##
 # Arguments
 
+operation=
+
 for arg in "$@" ; do
     case "$arg" in
         --debug)
@@ -444,9 +459,14 @@ for arg in "$@" ; do
         --help)
             help_cmdline=true
         ;;
-        *)
+        start|stop|restart|setup|status)
+            [[ -z $operation ]] || { error "Multiple operations are not supported." ; exit 1 ; }
             operation=$arg
         ;;
+        *)
+            error "Unsupported argument (try \"--help\")"
+            exit 1
+        ;;
     esac
 done