Upades of the Git chapter.

Signed-off-by: V-Z <vojta@trapa.cz>

Author: V-Z

presentation/linux_bash_metacentrum_course.tex

@@ -3095,7 +3095,7 @@ \subsection{Regular expressions}
 %
 % \begin{frame}{Text tasks}
 % 	\begin{enumerate}
-% 		\item
+% 		\item 
 % 	\end{enumerate}
 % \end{frame}
 
@@ -4347,29 +4347,69 @@ \subsection{Data storage}
 %
 % \begin{frame}{MetaCloud}
 % 	\begin{itemize}
-% 		\item
+% 		\item 
 % 	\end{itemize}
 % \end{frame}
 
-
-\section{Git} % TODO More general info about Git, separate GitHub to extra slide
+\section{Git}
 
 \begin{frame}{Git}
 	\tableofcontents[currentsection, sectionstyle=show/hide, hideothersubsections]
 \end{frame}
 
-\begin{frame}[fragile]{Git and GitHub}
+\subsection{Git principle}
+
+\begin{frame}[allowframebreaks]{Git and version control}
 	\begin{itemize}
 		\item \href{https://git-scm.com/}{Git} is \href{https://en.wikipedia.org/wiki/Version_control}{version controlling} system --- it traces changes among all versions --- absolutely crucial for any software development
-		\item \href{https://github.com/}{GitHub} is currently probably the most popular platform to host development of open-source projects, see \href{https://help.github.com/}{documentation}
-		\item Older (nowadays not so common) version controlling systems is Subversion (SVN), there are many more (Bazaar,~\ldots)
+		\item Older (nowadays not so common) version controlling systems is Subversion (SVN), there are many more (Bazaar, Mercurial,~\ldots)
 		\item Probably the best textbook for Git is \href{https://git-scm.com/book/en/v2}{Chacon's Pro Git}
 		\begin{itemize}
 			\item Dostupná i~\href{https://git-scm.com/book/cs/v2}{česky} (včetně \href{https://knihy.nic.cz/}{prvního vydání})
 		\end{itemize}
 		\item Changes and their history is stored in repository (local or network, shared or private) --- it is possible to view any historical state and differences between any versions
 		\item It is possible to trace who and when did what
 		\item Branching and merging of branches helps with making of big changes
+		\item Users work on a project in some directory as usually and from time to time commit local changes to stagging (temporal area) and then push them to remote or local repository (directory storing all Git history of particular project, can be anywhere)
+		\item Every commit is checkpoint in the history
+		\begin{itemize}
+			\item Can be tagged (named), e.g. particular released version of software, or project stage
+			\item User can compare any two commits or commit and current state
+		\end{itemize}
+		\item Code can be branched
+		\begin{itemize}
+			\item When new branch is created, it contains copy of current state
+			\item User selects in which branch she/he is working, the branches are diverging, user can commit in every branch independently
+			\item Commits in various branches can be compared and branches can be merged again
+			\item Key feature of Git --- branches are useful when user starts to work on any big change in the project
+		\end{itemize}
+		\item Stagging area serves as local \enquote{container} of changes to be pushed to central Git repository (or to be modified, discarded)
+		\begin{itemize}
+			\item It is very hard to do any change in the central Git repository (e.g. to remove accidentaly pushed file or change description)
+		\end{itemize}
+		\item Central repository keeps whole history of the project
+		\begin{itemize}
+			\item Every user has full copy of the central Git repository --- can be large
+			\item Can be placed on some server, network disk, in the local computer,~\ldots
+		\end{itemize}
+		\item Git was developed by Linus to trace development of Linux kernel, now it is probably the most used version control tool, used also by Microsoft to trace development of Windows :-)
+	\end{itemize}
+\end{frame}
+
+\begin{frame}{GitHub and others}
+	\begin{itemize}
+		\item \href{https://github.com/}{GitHub} is currently probably the most popular platform to host development of open-source projects, see \href{https://help.github.com/}{documentation}
+		\item Probably second most common on-line service providing Git repository is \href{https://about.gitlab.com/}{GitLab}
+		\begin{itemize}
+			\item User can create an account on GitLab (as on GitHub), or download and install GitLab system on own server
+		\end{itemize}
+		\item \href{https://sourceforge.net/}{SourceForge} used to be more popular in the past, still harbours plenty of interesting projects
+		\item For on-line services, many tools are available only for paying customers
+		\item All such services provide Git repositories accessible through standard tools (from command line, see further; or from some special application)
+		\begin{itemize}
+			\item Exact usage might differ from standard Git, check respective help pages first
+		\end{itemize}
+		\item Git repository can be easily hosted e.g. on any Linux server\ldots
 	\end{itemize}
 \end{frame}
 
@@ -4392,7 +4432,7 @@ \section{Git} % TODO More general info about Git, separate GitHub to extra slide
 			\end{itemize}
 		\end{itemize}
 		\begin{center}
-			\includegraphics[height=5.75cm]{git.png}
+			\includegraphics[height=6.5cm]{git.png}
 		\end{center}
 		\begin{flushright}
 			\begin{footnotesize}
@@ -4402,10 +4442,14 @@ \section{Git} % TODO More general info about Git, separate GitHub to extra slide
 	\end{multicols}
 \end{frame}
 
+\subsection{Git basics}
+
 \begin{frame}[fragile]{Working with Git --- start and sending changes}
 	\begin{bashcode}
-    # Create a new repository for new project
+    # Create a new repository for new project (in empty directory)
     git init # No need when cloning from existing repository
+    # Create a new central repository (e.g. on a server) in empty directory
+    git init --bare
     # Or checkout (make a copy) for another local or remote repository
     git clone /path/to/local/repository # Locally mounted repository
     git clone username@host:/path/to/remote/repository # Over SSH
@@ -4420,13 +4464,13 @@ \section{Git} % TODO More general info about Git, separate GitHub to extra slide
     git remote add origin <location> # Do only once on the beginning
     # <location> can be remote server or local path
     git remote add origin . # For repository within working directory
-    # Push changes into the repository (regardless where it is)
-    git push origin master # See further for selection of branches
 	\end{bashcode}
 \end{frame}
 
 \begin{frame}[fragile]{Working with Git --- branching and getting changes}
 	\begin{bashcode}
+    # Push changes into the repository (regardless where it is)
+    git push origin master # See further for selection of branches
     # Making new branch and switching to it
     git checkout -b NewFeature # Now we are in branch NewFeature
     # Switch back to branch master
@@ -4444,13 +4488,13 @@ \section{Git} % TODO More general info about Git, separate GitHub to extra slide
     git pull # Fetch and merge remote changes (before commit)
     # Merge another branch into the current one
     git merge <branch>
-    # In case of conflict, git shows editor and user must fix it manually
-    git add <file with conflict> # Needed to re-add conflicting file
 	\end{bashcode}
 \end{frame}
 
 \begin{frame}[fragile]{Working with Git --- tags, logs and settings}
 	\begin{bashcode}
+    # In case of conflict, git shows editor and user must fix it manually
+    git add <file with conflict> # Needed to re-add conflicting file
     # To see changes before merging
     git diff <source_branch> <target_branch>
     # Tagging e.g. milestones, released versions of software, etc.
@@ -4467,9 +4511,16 @@ \section{Git} % TODO More general info about Git, separate GitHub to extra slide
     git config format.pretty oneline # Nicer log output
     ~/.git # Contains user's settings, .git in every repository contains
            # data and settings for particular repository
+           # Default behavior of Git can be heavily altered
 	\end{bashcode}
 \end{frame}
 
+% \begin{frame}{Git tasks} % TODO Add Git tasks
+% 	\begin{itemize}
+% 		\item 
+% 	\end{itemize}
+% \end{frame}
+
 \section{Administration}
 
 \begin{frame}{Administration}
@@ -4478,7 +4529,7 @@ \section{Administration}
 
 % \begin{frame}{Btrfs and Snapper} % TODO Btrfs, Snapper
 % 	\begin{itemize}
-% 		\item
+% 		\item 
 % 	\end{itemize}
 % \end{frame}
 
@@ -4528,7 +4579,7 @@ \subsection{System services}
 
 % \begin{frame}{Security} % TODO Security, antiviruses
 % 	\begin{itemize}
-% 		\item
+% 		\item 
 % 	\end{itemize}
 % \end{frame}
 
@@ -4542,7 +4593,7 @@ \section{The End}
 %
 % \begin{frame}[allowframebreaks]{Brief list of applications to help to switch to Linux}
 % 	\begin{itemize}
-% 		\item
+% 		\item 
 % 	\end{itemize}
 % \end{frame}