diff --git a/install.sh b/install.sh
index d5dbd42..50bdbc0 100644
--- a/install.sh
+++ b/install.sh
@@ -58,14 +58,14 @@ checkSystem() {
         removeType='yum -y remove'
         upgrade="yum update -y --skip-broken"
         checkCentosSELinux
-    elif [[ -f "/etc/issue" ]] && grep </etc/issue -q -i "debian" || [[ -f "/proc/version" ]] && grep </etc/issue -q -i "debian" || [[ -f "/etc/os-release" ]] && grep </etc/os-release -q -i "ID=debian"; then
+    elif { [[ -f "/etc/issue" ]] && grep -qi "debian" /etc/issue; } || { [[ -f "/proc/version" ]] && grep -qi "debian" /proc/version;} || { [[ -f "/etc/os-release" ]] && grep -qi "ID=debian" /etc/issue; }; then
         release="debian"
         installType='apt -y install'
         upgrade="apt update"
         updateReleaseInfoChange='apt-get --allow-releaseinfo-change update'
         removeType='apt -y autoremove'
 
-    elif [[ -f "/etc/issue" ]] && grep </etc/issue -q -i "ubuntu" || [[ -f "/proc/version" ]] && grep </etc/issue -q -i "ubuntu"; then
+    elif { [[ -f "/etc/issue" ]] && grep -qi "ubuntu" /etc/issue; } || { [[ -f "/proc/version" ]] && grep -qi "ubuntu" /proc/version; }; then
         release="ubuntu"
         installType='apt -y install'
         upgrade="apt update"
@@ -74,11 +74,11 @@ checkSystem() {
         if grep </etc/issue -q -i "16."; then
             release=
         fi
-    elif [[ -f "/etc/issue" ]] && grep </etc/issue -q -i "Alpine" || [[ -f "/proc/version" ]] && grep </proc/version -q -i "Alpine"; then
+    elif { [[ -f "/etc/issue" ]] && grep -qi "Alpine" /etc/issue; } || { [[ -f "/proc/version" ]] && grep -qi "Alpine" /proc/version; }; then
         release="alpine"
         installType='apk add'
         upgrade="apk update"
-        removeType='apt del'
+        removeType='apk del'
         nginxConfigPath=/etc/nginx/http.d/
     fi