Added install script for pre-commit hook and updated readme.md with i…

…nstallation instructions

.generateDescription.py

@@ -5,12 +5,18 @@
 print ">> Updating README.md based on .codesnippet files"
 
 file = open('README.md', 'w')
-file.write('# CodeSnippets\n\nThese are my Xcode 4 CodeSnippets. Just clone them into the following path:  \n')
-file.write('The folder must be empty, to clone the repository directly in it.\n\n')
+file.write('# CodeSnippets\n\n')
+file.write('These are my Xcode 4 CodeSnippets.  \n')
+file.write('To use them, clone this repository into the following path:\n\n')
 file.write('    cd ~/Library/Developer/Xcode/UserData/CodeSnippets\n')
 file.write('    git clone git@github.com:jaydee3/CodeSnippets.git .\n\n')
+file.write('(The folder must be empty, to clone the repository directly in it.)  \n')
 file.write('And you\'re ready to go.\n\n')
-file.write('## Snippet Descriptions\n\n(generated with .generateDescription.py)\n\n')
+file.write('#### Installing the pre-commit hook  \n')
+file.write('This README is generated automatically using `.generateDescription.py`.  \n')
+file.write('To run this script automatically before each commit, install the pre-commit hook like this:\n\n')
+file.write('    sh .install-precommit-hook.sh\n\n')
+file.write('## Snippet Descriptions\n\n')
 
 listing = os.listdir(".")
 for fileName in listing:

.install-precommit-hook.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+#
+# Installs the pre-commit git hook
+# which will automatically update the README.md
+# and stage it for the current commit right before
+# every actual commit
+#
+
+hookfile=".pre-commit.hook"
+target=".git/hooks/pre-commit"
+backupTarget=".git/hooks/pre-commit.backup"
+
+# file existing options
+cancel=false
+overwrite=false
+backup=false
+
+# ask what to do with existing file
+if [ -e "$target" ] || [ -h "$target" ]; then
+    echo "A pre-commit hook already exists!"
+    echo "[c]ancel, [o]verwrite or [b]ackup"
+    while true; do
+        read answer
+        case $answer in
+            "c" ) cancel=true; break;;
+            "o" ) overwrite=true; break;;
+            "b" ) backup=true; break;;
+            *   ) continue ;;
+        esac
+    done
+
+    if $overwrite; then
+        rm $target
+    fi
+
+    if $backup; then
+        mv $target $backupTarget 
+        echo "Saved old hook as $backupTarget"
+    fi
+fi
+
+# cancel or install
+if $cancel; then
+    echo "Canceled"
+else
+    cp $hookfile $target
+    echo "Installed hook: $target"
+fi
+
+

.pre-commit.hook

@@ -0,0 +1,9 @@
+#!/bin/sh
+#
+# generate documentation, before commiting
+# this will update the readme.md
+#
+
+python .generateDescription.py
+git add README.md
+

README.md

@@ -1,16 +1,21 @@
 # CodeSnippets
 
-These are my Xcode 4 CodeSnippets. Just clone them into the following path:  
-The folder must be empty, to clone the repository directly in it.
+These are my Xcode 4 CodeSnippets.  
+To use them, clone this repository into the following path:
 
     cd ~/Library/Developer/Xcode/UserData/CodeSnippets
     git clone git@github.com:jaydee3/CodeSnippets.git .
 
+(The folder must be empty, to clone the repository directly in it.)  
 And you're ready to go.
 
-## Snippet Descriptions
+#### Installing the pre-commit hook  
+This README is generated automatically using `.generateDescription.py`.  
+To run this script automatically before each commit, install the pre-commit hook like this:
+
+    sh .install-precommit-hook.sh
 
-(generated with .generateDescription.py)
+## Snippet Descriptions
 
 **allocInit.codesnippet**  (Initalize an object)  
 Shortcut: `alloc`