contrib/install-system-wide in rvm-1.0.5 vs contrib/install-system-wide in rvm-1.0.6

@@ -1,27 +1,86 @@
 #!/usr/bin/env bash
 
+usage() {
+  printf "
+
+  Usage:
+
+    rvm-install-system-wide [options]
+
+  Options:
+
+    --trace      - Run turn on bash xtrace while the script runs.
+    --debug      - Turn on bash verbose while the script runs.
+    --version X  - Install RVM version X
+    --revision X - Install RVM revision X (sha1)
+    --help       - Display this usage text.
+
+"
+return 0
+}
+
 __rvm_system_wide_permissions() {
   [[ -z "$1" ]] && return 1
+
   chown -R root:"$rvm_group_name" "$1"
+
   chmod -R g+w "$1"
-  [[ -d "$1" ]] && find "$1" -type d -print0 | xargs -n1 -0 chmod g+s
+
+  if [[ -d "$1" ]] ; then
+    find "$1" -type d -print0 | xargs -n1 -0 chmod g+s
+  fi
+
+  return 0
 }
 
 # Require root to install it.
 if [[ "$(whoami)" != "root" ]]; then
   echo "Please rerun this installer as root." >&2
   exit 1
+
 # Check for the presence of git.
-elif ! command -v git >/dev/null 2>&1 ; then
+elif [[ -z "$(command -v git)" ]] ; then
   echo "Please ensure git is installed and available in PATH to continue." >&2
   exit 1
+
 elif [[ "$(uname)" != "Linux" ]]; then
   echo "The rvm system wide installer is currently Linux only." >&2
   exit 1
 fi
 
+while [[ $# -gt 0 ]] ; do
+  case $1 in
+    --trace)
+      rvm_trace_flag=1
+      set -o xtrace
+      ;;
+    --debug)
+      rvm_trace_flag=1
+      set -o verbose
+      ;;
+    --version|--revision)
+      if [[ -n "${1:-""}" ]] ; then
+        revision="$1"
+        shift
+      else
+        usage
+        exit 1
+      fi
+      ;;
+    --help)
+      usage
+      exit 0
+      ;;
+    *)
+      usage
+      exit 1
+    ;;
+  esac
+  shift
+done
+
 # Load the rvm config.
 rvm_ignore_rvmrc=${rvm_ignore_rvmrc:-0}
 if [[ $rvm_ignore_rvmrc -eq 0 ]]; then
   [[ -s /etc/rvmrc ]] && source /etc/rvmrc
   [[ -s "$HOME/.rvmrc" ]] && source "$HOME/.rvmrc"
@@ -39,22 +98,27 @@
 fi
 echo "Adding $(whoami) the '$rvm_group_name'"
 usermod -a -G "$rvm_group_name" "$(whoami)"
 
 echo "Creating the destination dir and making sure the permissions are correct"
-\mkdir -p "$rvm_path"
+mkdir -p "$rvm_path"
 __rvm_system_wide_permissions "$rvm_path"
 
-\mkdir -p "$rvm_path/src/"
+mkdir -p "$rvm_path/src/"
 builtin cd "$rvm_path/src"
 
-\rm -rf ./rvm/
+rm -rf ./rvm/
 
 git clone --depth 1 git://github.com/wayneeseguin/rvm.git || git clone http://github.com/wayneeseguin/rvm.git
 
 builtin cd rvm
 
+if [[ "${revision:-""}" ]]; then
+  echo "Checking out revision $revision"
+  git checkout $revision
+fi
+
 echo "Running the install script."
 bash ./scripts/install "$@"
 
 __rvm_system_wide_permissions "$rvm_path"
 
@@ -63,12 +127,12 @@
 for dir in bin share/man; do
   __rvm_system_wide_permissions "$rvm_parent_dir/$dir"
 done; unset dir
 
 echo "Generating system wide rvmrc"
-\rm -f /etc/rvmrc
-\touch /etc/rvmrc
+rm -f /etc/rvmrc
+touch /etc/rvmrc
 cat > /etc/rvmrc <<END_OF_RVMRC
 # Setup default configuration for rvm.
 # If an rvm install exists in the home directory, don't load this.'
 if [[ ! -s "\$HOME/.rvm/scripts/rvm" ]]; then
   umask g+w
@@ -76,11 +140,11 @@
   export rvm_prefix="$rvm_parent_dir/"
 fi
 END_OF_RVMRC
 
 echo "Generating $rvm_parent_dir/lib/rvm to load rvm"
-\rm -f "$rvm_parent_dir/lib/rvm"
-\touch "$rvm_parent_dir/lib/rvm"
+rm -f "$rvm_parent_dir/lib/rvm"
+touch "$rvm_parent_dir/lib/rvm"
 cat > "$rvm_parent_dir/lib/rvm" <<END_OF_RVM_SH
 # Automatically source rvm
 if [[ -s "\$HOME/.rvm/scripts/rvm" ]]; then
   source "\$HOME/.rvm/scripts/rvm"
 elif [[ -s "/usr/local/rvm/scripts/rvm" ]]; then