install-system-wide in rvm-1.1.4

- old
+ new

@@ -83,11 +83,11 @@
 }
 
 os_type="$(uname)"
 
 # Require root to install it.
-if [[ "$(whoami)" != "root" ]]; then
+if [[ $(id -u) -ne 0 ]]; then
   echo "Please rerun this installer as root." >&2
   exit 1
 
 # Check for the presence of git.
 elif [[ -z "$(command -v git)" ]] ; then
@@ -152,10 +152,10 @@
 export rvm_selfcontained=0
 
 rvm_group_name="${rvm_group_name:-"rvm"}"
 
 __rvm_create_user_group "$rvm_group_name"
-__rvm_add_user_to_group "$(whoami)" "$rvm_group_name"
+__rvm_add_user_to_group "$USER" "$rvm_group_name"
 
 echo "Creating the destination dir and making sure the permissions are correct"
 mkdir -p "$rvm_path"
 __rvm_system_wide_permissions "$rvm_path"
 