@@ -548,6 +548,26 @@ function install_package() {

 }

+# Distro-agnostic function to tell if a package is installed

+# is_package_installed package [package ...]

+function is_package_installed() {

+    if [[ -z "$@" ]]; then

+        return 1

+    fi

+

+    if [[ -z "$os_PACKAGE" ]]; then

+        GetOSVersion

+    fi

+    if [[ "$os_PACKAGE" = "deb" ]]; then

+        dpkg -l "$@" > /dev/null

+        return $?

+    else

+        rpm --quiet -q "$@"

+        return $?

+    fi

+}

+

+

 # Test if the named environment variable is set and not zero length

 # is_set env-var

 function is_set() {

@@ -182,11 +182,7 @@ if [[ $EUID -eq 0 ]]; then

     sleep $ROOTSLEEP

     # Give the non-root user the ability to run as **root** via ``sudo``

-    if [[ "$os_PACKAGE" = "deb" ]]; then

-        dpkg -l sudo || install_package sudo

-    else

-        rpm -qa | grep sudo || install_package sudo

-    fi

+    is_package_installed sudo || install_package sudo

     if ! getent group stack >/dev/null; then

         echo "Creating a group called stack"

         groupadd stack

@@ -215,12 +211,7 @@ if [[ $EUID -eq 0 ]]; then

     exit 1

 else

     # We're not **root**, make sure ``sudo`` is available

-    if [[ "$os_PACKAGE" = "deb" ]]; then

-        CHECK_SUDO_CMD="dpkg -l sudo"

-    else

-        CHECK_SUDO_CMD="rpm -q sudo"

-    fi

-    $CHECK_SUDO_CMD || die "Sudo is required.  Re-run stack.sh as root ONE TIME ONLY to set up sudo."

+    is_package_installed sudo || die "Sudo is required.  Re-run stack.sh as root ONE TIME ONLY to set up sudo."

     # UEC images ``/etc/sudoers`` does not have a ``#includedir``, add one

     sudo grep -q "^#includedir.*/etc/sudoers.d" /etc/sudoers ||

@@ -239,3 +239,44 @@ test_disable_negated_services 'a,-a' ''

 test_disable_negated_services 'b,a,-a' 'b'

 test_disable_negated_services 'a,b,-a' 'b'

 test_disable_negated_services 'a,-a,b' 'b'

+

+

+echo "Testing is_package_installed()"

+

+if [[ -z "$os_PACKAGE" ]]; then

+    GetOSVersion

+fi

+

+if [[ "$os_PACKAGE" = "deb" ]]; then

+    is_package_installed dpkg

+    VAL=$?

+else

+    is_package_installed rpm

+    VAL=$?

+fi

+if [[ "$VAL" -eq 0 ]]; then

+    echo "OK"

+else

+    echo "is_package_installed() on existing package failed"

+fi

+

+if [[ "$os_PACKAGE" = "deb" ]]; then

+    is_package_installed dpkg bash

+    VAL=$?

+else

+    is_package_installed rpm bash

+    VAL=$?

+fi

+if [[ "$VAL" -eq 0 ]]; then

+    echo "OK"

+else

+    echo "is_package_installed() on more than one existing package failed"

+fi

+

+is_package_installed zzzZZZzzz

+VAL=$?

+if [[ "$VAL" -ne 0 ]]; then

+    echo "OK"

+else

+    echo "is_package_installed() on non-existing package failed"

+fi