installation with curl and bash

Installation.md

@@ -24,5 +24,5 @@ $ [sudo] make install
 One-liner:
 
 ```bash
-$ (cd /tmp && rm -rf git-extras && echo "Setting up 'git-extras'...." && git clone https://github.com/tj/git-extras.git &> /dev/null && cd git-extras && git checkout $(git describe --tags $(git rev-list --tags --max-count=1)) &> /dev/null && sudo make install)
+curl -s https://raw.githubusercontent.com/tj/git-extras/master/install.sh | [sudo] bash /dev/stdin
 ```

bin/git-extras

@@ -1,19 +1,14 @@
 #!/usr/bin/env bash
 
 VERSION="3.0.0"
+INSTALL_SCRIPT="https://raw.githubusercontent.com/tj/git-extras/master/install.sh"
 
 update() {
   local bin=$(which git-extras)
   local prefix=${bin%/*/*}
   local orig=$PWD
 
-  cd /tmp \
-    && rm -fr ./git-extras \
-    && echo "Setting up 'git-exras'...." \
-    && git clone https://github.com/tj/git-extras.git &> /dev/null \
-    && cd git-extras \
-    && git checkout $(git describe --tags $(git rev-list --tags --max-count=1)) &> /dev/null \
-    && PREFIX="$prefix" make install \
+  curl -s $INSTALL_SCRIPT | PREFIX="$prefix" bash /dev/stdin \
     && cd "$orig" \
     && echo "... updated git-extras $VERSION -> $(git extras --version)"
 }

install.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+make_install() {
+    if [ -n "$PREFIX" ]
+    then
+        PREFIX="$PREFIX" make install
+    else
+        sudo make install
+    fi
+}
+
+cd /tmp \
+    && rm -rf ./git-extras \
+    && echo "Setting up 'git-exras'...." \
+    && git clone https://github.com/tj/git-extras.git &> /dev/null \
+    && cd git-extras \
+    && git checkout \
+        $(git describe --tags $(git rev-list --tags --max-count=1)) \
+        &> /dev/null \
+    && make_install
+