git add : blob creation

presentation.tex

@@ -104,6 +104,7 @@ time so that you can recall specific versions later.
   \frametitle{Creating a git repository}
 
 Creating a project folder
+\vspace{-1em}
 \begin{shcode}
 ~ $ mkdir alpha
 ~ $ cd alpha
@@ -112,16 +113,19 @@ Creating a project folder
 ~/alpha $ data/letter.txt
 \end{shcode}
 we have :
+\vspace{-1em}
 \begin{shcode}
 alpha
 └── data
     └── letter.txt
 \end{shcode}
+\vspace{-1em}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{Creating a git repository}
 Creating a git repository
+\vspace{-1em}
 \begin{shcode}
 ~/alpha $ git init
 Initialized empty Git repository in alpha/.git/
@@ -129,6 +133,7 @@ Initialized empty Git repository in alpha/.git/
 we have :
 \begin{columns}
   \begin{column}{0.6\textwidth}
+\vspace{-1em}
 \begin{shcode}
 alpha
 ├── data
@@ -137,16 +142,63 @@ alpha
     ├── objects
     etc...
 \end{shcode}
+\vspace{-1em}
   \end{column}
   \begin{column}{0.4\textwidth}
     \includegraphics[width=0.9\textwidth]{./img/vcs_local.png}
   \end{column}
 \end{columns}
 
-The \texttt{.git} directory and its contents are Git’s.
+The \mintinline{sh}{.git} directory and its contents are Git’s.
 All the other files are collectively known as the \textbf{working copy}.
 They are the user’s.
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{tracking a file with git}
+We want to track the modification made to \mintinline{sh}{letter.txt}
+\vspace{-1em}
+\begin{shcode}
+~/alpha $ git add data/letter.txt
+\end{shcode}
+git create a new blob file in the \mintinline{sh}{.git/objects/} directory.
+\vspace{-1em}
+\begin{shcode}
+alpha
+├── data
+│   └── letter.txt
+└── .git
+    ├── objects
+    │   ├── 78
+    │   │   └── 981922613b2afb6025042ff6bd878ac1994e85
+    etc...
+\end{shcode}
+\vspace{-1em}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{tracking a file with git}
+We want to track the modification made to \mintinline{sh}{letter.txt}\\[-2em]
+\begin{shcode}
+~/alpha $ git add data/letter.txt
+\end{shcode}
+\vspace{-2.5em}
+
+git create a new \textbf{blob} file in the \mintinline{sh}{.git/objects/} directory\\[-2em]
+\begin{shcode}
+    ├── objects
+    │   ├── 78
+    │   │   └── 981922613b2afb6025042ff6bd878ac1994e85
+\end{shcode}
+\vspace{-2.5em}
 
+Git \textbf{blob}:\\[-2.5em]
+\begin{itemize}
+  \item contains the compressed content of a file
+  \item The name of the blob is the SHA1 of the file.
+  \item The first two characters of the SHA1 are used as the name of a directory inside the objects folder
+  \item The rest of the hash is used as the name of the blob file
+\end{itemize}
 \end{frame}
 
 \end{document}