git, curl and wget now all in one installer

install.sh

@@ -2,34 +2,73 @@
 
 set -e
 
-if [ ! "$NVM_SOURCE" ]; then
-  NVM_SOURCE="https://github.com/creationix/nvm.git"
-fi
+has() {
+  type "$1" > /dev/null 2>&1
+  return $?
+}
 
-if [ ! "$NVM_DIR" ]; then
+if [ -z "$NVM_DIR" ]; then
   NVM_DIR="$HOME/.nvm"
 fi
 
-if ! hash git 2>/dev/null; then
-  echo >&2 "You need to install git - visit http://git-scm.com/downloads"
-  echo >&2 "or, use install-gitless.sh instead."
-  exit 1
-fi
+download_file() {
+  # download_file source destination
+  if has "curl"; then
+    curl --silent "$1" -o "$2"
+  elif has "wget"; then
+    wget --quiet "$1" -O "$2"
+  else
+    return 1
+  fi
+}
 
-if [ -d "$NVM_DIR" ]; then
-  echo "=> NVM is already installed in $NVM_DIR, trying to update"
-  echo -e "\r=> \c"
-  cd "$NVM_DIR" && git pull
-else
-  # Cloning to $NVM_DIR
+install_from_git() {
+  if [ -z "$NVM_SOURCE" ]; then
+    NVM_SOURCE="https://github.com/creationix/nvm.git"
+  fi
+
+  if [ -d "$NVM_DIR/.git" ]; then
+    echo "=> NVM is already installed in $NVM_DIR, trying to update"
+    echo -e "\r=> \c"
+    cd "$NVM_DIR" && git pull
+  else
+    # Cloning to $NVM_DIR
+    mkdir -p "$NVM_DIR"
+    git clone "$NVM_SOURCE" "$NVM_DIR"
+  fi
+}
+
+install_as_script() {
+  if [ -z "$NVM_SOURCE" ]; then
+    NVM_SOURCE="https://raw.github.com/creationix/nvm/master/nvm.sh"
+  fi
+
+  # Downloading to $NVM_DIR
   mkdir -p "$NVM_DIR"
-  git clone "$NVM_SOURCE" "$NVM_DIR"
+  if [ -d "$NVM_DIR/nvm.sh" ]; then
+    echo "=> NVM is already installed in $NVM_DIR, trying to update"
+  else
+    echo "=> Downloading NVM to '$NVM_DIR'"
+  fi
+  download_file "$NVM_SOURCE" "$NVM_DIR/nvm.sh" || {
+    echo >&2 "Failed.."
+    return 1
+  }
+}
+
+if has "git"; then
+ install_from_git
+else
+  install_as_script || {
+    echo >&2 -e "You need git, curl or wget to install NVM"
+    exit 1
+  }
 fi
 
 echo
 
 # Detect profile file if not specified as environment variable (eg: PROFILE=~/.myprofile).
-if [ ! "$PROFILE" ]; then
+if [ -z "$PROFILE" ]; then
   if [ -f "$HOME/.bash_profile" ]; then
     PROFILE="$HOME/.bash_profile"
   elif [ -f "$HOME/.zshrc" ]; then