diff --git a/scripts/lib/common.sh b/scripts/lib/common.sh
index 8b79031..aba232c 100644
--- a/scripts/lib/common.sh
+++ b/scripts/lib/common.sh
@@ -158,7 +158,7 @@ confirm_destructive() {
     if [[ "${GITEA_YES:-0}" == "1" ]]; then
         return 0
     fi
-    if [[ ! -r /dev/tty ]]; then
+    if ! { true < /dev/tty; } 2>/dev/null; then
         log_err "需要確認但無 TTY；請加 -y / --yes 或設定 GITEA_YES=1"
         exit 1
     fi
@@ -178,7 +178,7 @@ confirm_exact_match() {
     if [[ "${GITEA_YES:-0}" == "1" ]]; then
         return 0
     fi
-    if [[ ! -r /dev/tty ]]; then
+    if ! { true < /dev/tty; } 2>/dev/null; then
         log_err "需要確認但無 TTY；請加 -y / --yes 或設定 GITEA_YES=1"
         exit 1
     fi