Add invite and QR code features to backtunnel-share

scripts/backtunnel-share

@@ -4,7 +4,7 @@
 
 # backtunnel-share: Share a folder using reverse SSH for a limited duration
 # Syntax: backtunnel-share /path/to/folder with remoteuser:remotehost for 2h
-# Options: -p|--tunnel-port <PORT>  -l|--local-ssh-port <PORT>  -h|--help
+# Options: -p|--tunnel-port <PORT>  -l|--local-ssh-port <PORT>  -i|--invite [--invite-mount <PATH>] [--invite-file <FILE>] [--qr]  -h|--help
 
 set -euo pipefail
 
@@ -12,6 +12,11 @@ TUNNEL_PORT=2222       # remote-side port exposed via -R
 LOCAL_SSH_PORT=22      # local sshd port to forward to
 DURATION=""            # required: e.g. 30m, 2h, 1d
 
+INVITE=false           # print a ready-to-copy access command
+INVITE_MOUNT="/mnt/remote-rssh"
+INVITE_FILE=""
+QR=false               # render invite as terminal QR (requires qrencode)
+
 usage() {
   cat >&2 <<EOF
 Usage:
@@ -27,11 +32,16 @@ Positional (required, in order):
 Options:
   -p, --tunnel-port N       Remote tunnel port (default: ${TUNNEL_PORT})
   -l, --local-ssh-port N    Local sshd port to expose (default: ${LOCAL_SSH_PORT})
+  -i, --invite              Print a ready-to-copy access command for the remote side
+      --invite-mount PATH   Mount point suggested in invite (default: ${INVITE_MOUNT})
+      --invite-file FILE    Also write the invite text (with unmount hint) to FILE
+      --qr                  Also print a QR code (requires 'qrencode')
   -h, --help                Show this help
 
 Examples:
   $(basename "$0") ~/projects with alice:vps.example.com for 2h
   $(basename "$0") ~/projects with alice@vps.example.com for 1d -p 4422 -l 2222
+  $(basename "$0") ~/projects with alice@vps.example.com for 2h -i --qr
 EOF
   exit 1
 }
@@ -62,6 +72,24 @@ while [[ $# -gt 0 ]]; do
       LOCAL_SSH_PORT=$2
       shift 2
       ;;
+    -i|--invite)
+      INVITE=true
+      shift
+      ;;
+    --invite-mount)
+      [[ $# -lt 2 ]] && usage
+      INVITE_MOUNT=$2
+      shift 2
+      ;;
+    --invite-file)
+      [[ $# -lt 2 ]] && usage
+      INVITE_FILE=$2
+      shift 2
+      ;;
+    --qr)
+      QR=true
+      shift
+      ;;
     -h|--help)
       usage
       ;;
@@ -101,6 +129,38 @@ echo "    remote bind port    : ${TUNNEL_PORT} (on ${REMOTE_HOST})"
 echo "    remote user         : ${REMOTE_USER}"
 echo "    duration            : ${DURATION}"
 echo
+
+# --- print invite (optional) ---
+if $INVITE; then
+  INVITE_CMD="backtunnel-access '${FOLDER}' from ${REMOTE_USER}@${REMOTE_HOST} -p ${TUNNEL_PORT} -m '${INVITE_MOUNT}'"
+  INVITE_TEXT=$(
+    cat <<EOT
+# Paste this on the REMOTE host (or SSH there first, then paste):
+${INVITE_CMD}
+# Unmount when done:
+fusermount -u '${INVITE_MOUNT}'
+EOT
+  )
+  echo "🔗 Invite (copy to chat):"
+  echo "------------------------------------------------------------"
+  echo "${INVITE_CMD}"
+  echo "------------------------------------------------------------"
+  if [[ -n "${INVITE_FILE}" ]]; then
+    printf "%s\n" "${INVITE_TEXT}" > "${INVITE_FILE}"
+    echo "Saved invite to: ${INVITE_FILE}"
+  fi
+  if $QR; then
+    if command -v qrencode >/dev/null 2>&1; then
+      echo
+      echo "📱 QR (scan to copy the command):"
+      printf "%s" "${INVITE_CMD}" | qrencode -t ansiutf8
+    else
+      echo "⚠️  'qrencode' not installed; skipping QR."
+    fi
+  fi
+  echo
+fi
+
 echo "Tip: On the remote side, mount with:"
 echo "     backtunnel-access '${FOLDER}' from ${REMOTE_USER}@${REMOTE_HOST} -p ${TUNNEL_PORT}"