1.1 --- a/en/tour.tex	Thu Oct 12 10:33:03 2006 -0700
     1.2 +++ b/en/tour.tex	Thu Oct 12 16:01:40 2006 -0700
     1.3 @@ -145,8 +145,8 @@
     1.4  
     1.5  To introduce a little terminology, the \dirname{.hg} directory is the
     1.6  ``real'' repository, and all of the files and directories that coexist
     1.7 -with it are said to live in the ``working directory''.  An easy way to
     1.8 -remember the distinction is that the \emph{repository} contains the
     1.9 +with it are said to live in the \emph{working directory}.  An easy way
    1.10 +to remember the distinction is that the \emph{repository} contains the
    1.11  \emph{history} of your project, while the \emph{working directory}
    1.12  contains a \emph{snapshot} of your project at a particular point in
    1.13  history.
    1.14 @@ -217,10 +217,9 @@
    1.15  \subsection{Viewing specific revisions}
    1.16  
    1.17  To narrow the output of \hgcmd{log} down to a single revision, use the
    1.18 -\hgopt{log}{-r} option.  You can use either a revision number or a
    1.19 -long-form changeset identifier, and you can provide as many revisions
    1.20 -as you want.
    1.21 -\interaction{tour.log-r}
    1.22 +\hgopt{log}{-r} (or \hgopt{log}{--rev}) option.  You can use either a
    1.23 +revision number or a long-form changeset identifier, and you can
    1.24 +provide as many revisions as you want.  \interaction{tour.log-r}
    1.25  
    1.26  If you want to see the history of several revisions without having to
    1.27  list each one, you can use \emph{range notation}; this lets you
    1.28 @@ -231,6 +230,248 @@
    1.29  \hgcmdargs{log}{-r 2:4} prints $2,3,4$ while \hgcmdargs{log}{-r 4:2}
    1.30  prints $4,3,2$.
    1.31  
    1.32 +\subsection{More detailed information}
    1.33 +
    1.34 +While the summary information printed by \hgcmd{log} is useful if you
    1.35 +already know what you're looking for, you may need to see a complete
    1.36 +description of the change, or a list of the files changed, if you're
    1.37 +trying to decide whether a changeset is the one you're looking for.
    1.38 +The \hgcmd{log} command's \hggopt{-v} (or \hggopt{--verbose})
    1.39 +option gives you this extra detail.
    1.40 +\interaction{tour.log-v}
    1.41 +
    1.42 +If you want to see both the description and content of a change, add
    1.43 +the \hgopt{log}{-p} (or \hgopt{log}{--patch}) option.  This displays
    1.44 +the content of a change as a \emph{unified diff} (if you've never seen
    1.45 +a unified diff before, see section~\ref{sec:mq:patch} for an overview).
    1.46 +\interaction{tour.log-vp}
    1.47 +
    1.48 +\section{All about command options}
    1.49 +
    1.50 +Let's take a brief break from exploring Mercurial commands to discuss
    1.51 +a pattern in the way that they work; you may find this useful to keep
    1.52 +in mind as we continiue our tour.
    1.53 +
    1.54 +Mercurial has a consistent and straightforward approach to dealing
    1.55 +with the options that you can pass to commands.  It follows the
    1.56 +conventions for options that are common to modern Linux and Unix
    1.57 +systems.
    1.58 +\begin{itemize}
    1.59 +\item Every option has a long name.  For example, as we've already
    1.60 +  seen, the \hgcmd{log} command accepts a \hgopt{log}{--rev} option.
    1.61 +\item Most options have short names, too.  Instead of
    1.62 +  \hgopt{log}{--rev}, we can use \hgopt{log}{-r}.  (The reason that
    1.63 +  some options don't have short names is that the options in question
    1.64 +  are rarely used.)
    1.65 +\item Long options start with two dashes (e.g.~\hgopt{log}{--rev}),
    1.66 +  while short options start with one (e.g.~\hgopt{log}{-r}).
    1.67 +\item Option naming and usage is consistent across commands.  For
    1.68 +  example, every command that lets you specify a changeset~ID or
    1.69 +  revision number accepts both \hgopt{log}{-r} and \hgopt{log}{--rev}
    1.70 +  arguments.
    1.71 +\end{itemize}
    1.72 +In the examples throughout this book, I use short options instead of
    1.73 +long.  This just reflects my own preference, so don't read anything
    1.74 +significant into it.
    1.75 +
    1.76 +Most commands that print output of some kind will print more output
    1.77 +when passed a \hggopt{-v} (or \hggopt{--verbose}) option, and less
    1.78 +when passed \hggopt{-q} (or \hggopt{--quiet}).
    1.79 +
    1.80 +\section{Making and reviewing changes}
    1.81 +
    1.82 +Now that we have a grasp of viewing history in Mercurial, let's take a
    1.83 +look at making some changes and examining them.
    1.84 +
    1.85 +The first thing we'll do is isolate our experiment in a repository of
    1.86 +its own.  We use the \hgcmd{clone} command, but we don't need to
    1.87 +clone a copy of the remote repository.  Since we already have a copy
    1.88 +of it locally, we can just clone that instead.  This is much faster
    1.89 +than cloning over the network, and cloning a local repository uses
    1.90 +less disk space in most cases, too.
    1.91 +\interaction{tour.reclone}
    1.92 +As an aside, it's often good practice to keep a ``pristine'' copy of a
    1.93 +remote repository around, which you can then make temporary clones of
    1.94 +to create sandboxes for each task you want to work on.  This lets you
    1.95 +work on multiple tasks in parallel, each isolated from the others
    1.96 +until it's complete and you're ready to integrate it back.  Because
    1.97 +local clones are so cheap, there's almost no overhead to cloning and
    1.98 +destroying repositories whenever you want.
    1.99 +
   1.100 +In our \dirname{my-hello} repository, we have a file
   1.101 +\filename{hello.c} that contains the classic ``hello, world'' program.
   1.102 +Let's use the ancient and venerable \command{sed} command to edit this
   1.103 +file so that it prints a second line of output.  (I'm only using
   1.104 +\command{sed} to do this because it's easy to write a scripted example
   1.105 +this way.  Since you're not under the same constraint, you probably
   1.106 +won't want to use \command{sed}; simply use your preferred text editor to
   1.107 +do the same thing.)
   1.108 +\interaction{tour.sed}
   1.109 +
   1.110 +Mercurial's \hgcmd{status} command will tell us what Mercurial knows
   1.111 +about the files in the repository.
   1.112 +\interaction{tour.status}
   1.113 +The \hgcmd{status} command prints no output for some files, but a line
   1.114 +starting with ``\texttt{M}'' for \filename{hello.c}.  Unless you tell
   1.115 +it to, \hgcmd{status} will not print any output for files that have
   1.116 +not been modified.  
   1.117 +
   1.118 +The ``\texttt{M}'' indicates that Mercurial has noticed that we
   1.119 +modified \filename{hello.c}.  Notice that we didn't need to
   1.120 +\emph{inform} Mercurial that we were going to modify the file before
   1.121 +we started, or that we had modified the file after we were done; it
   1.122 +was able to figure this out itself.
   1.123 +
   1.124 +It's a little bit helpful to know that we've modified
   1.125 +\filename{hello.c}, but we might prefer to know exactly \emph{what}
   1.126 +changes we've made to it.  To do this, we use the \hgcmd{diff}
   1.127 +command.
   1.128 +\interaction{tour.diff}
   1.129 +
   1.130 +\section{Recording changes in a new changeset}
   1.131 +
   1.132 +We can modify files, build and test our changes, and use
   1.133 +\hgcmd{status} and \hgcmd{diff} to review our changes, until we're
   1.134 +satisfied with what we've done and arrive at a natural stopping point
   1.135 +where we want to record our work in a new changeset.
   1.136 +
   1.137 +The \hgcmd{commit} command lets us create a new changeset; we'll
   1.138 +usually refer to this as ``making a commit'' or ``committing''.  
   1.139 +
   1.140 +\subsection{Writing a commit message}
   1.141 +
   1.142 +When we commit a change, Mercurial drops us into a text editor, to
   1.143 +enter a message that will describe the modifications we've made in
   1.144 +this changeset.  This is called the \emph{commit message}.  It will be
   1.145 +a record for readers of what we did and why, and it will be printed by
   1.146 +\hgcmd{log} after we've finished committing.
   1.147 +\interaction{tour.commit}
   1.148 +
   1.149 +The editor that the \hgcmd{commit} command drops us into will contain
   1.150 +an empty line, followed by a number of lines starting with
   1.151 +``\texttt{HG:}''.
   1.152 +\begin{codesample2}
   1.153 +  \emph{empty line}
   1.154 +  HG: changed hello.c
   1.155 +\end{codesample2}
   1.156 +Mercurial ignores the lines that start with ``\texttt{HG:}''; it uses
   1.157 +them only to tell us which files it's recording changes to.  Modifying
   1.158 +or deleting these lines has no effect.
   1.159 +
   1.160 +\subsection{Writing a good commit message}
   1.161 +
   1.162 +Since \hgcmd{log} only prints the first line of a commit message by
   1.163 +default, it's best to write a commit message whose first line stands
   1.164 +alone.  Here's a real example of a commit message that \emph{doesn't}
   1.165 +follow this guideline, and hence has a summary that is not readable.
   1.166 +\begin{codesample2}
   1.167 +  changeset:   73:584af0e231be
   1.168 +  user:        Censored Person <censored.person@example.org>
   1.169 +  date:        Tue Sep 26 21:37:07 2006 -0700
   1.170 +  summary:     include buildmeister/commondefs.   Add an exports and install
   1.171 +\end{codesample2}
   1.172 +
   1.173 +As far as the remainder of the contents of the commit message are
   1.174 +concerned, there are no hard-and-fast rules.  Mercurial itself doesn't
   1.175 +interpret or care about the contents of the commit message, though
   1.176 +your project may have policies that dictate a certain kind of
   1.177 +formatting.
   1.178 +
   1.179 +My personal preference is for short, but informative, commit messages
   1.180 +that tell me something that I can't figure out with a quick glance at
   1.181 +the output of \hgcmdargs{log}{--patch}.
   1.182 +
   1.183 +\subsection{Aborting a commit}
   1.184 +
   1.185 +If you decide that you don't want to commit while in the middle of
   1.186 +editing a commit message, simply exit from your editor without saving
   1.187 +the file that it's editing.  This will cause nothing to happen to
   1.188 +either the repository or the working directory.
   1.189 +
   1.190 +If we run the \hgcmd{commit} command without any arguments, it records
   1.191 +all of the changes we've made, as reported by \hgcmd{status} and
   1.192 +\hgcmd{diff}.
   1.193 +
   1.194 +\subsection{Admiring our new handywork}
   1.195 +
   1.196 +Once we've finished the commit, we can use the \hgcmd{tip} command to
   1.197 +display the changeset we just created.  This command produces output
   1.198 +that is identical to \hgcmd{log}, but it only displays the newest
   1.199 +revision in the repository.
   1.200 +\interaction{tour.tip}
   1.201 +We refer to the newest revision in the repository as the tip revision,
   1.202 +or simply the tip.
   1.203 +
   1.204 +\section{Sharing changes}
   1.205 +
   1.206 +We mentioned earlier that repositories in Mercurial are
   1.207 +self-contained.  This means that the changeset we just created exists
   1.208 +only in our \dirname{my-hello} repository.  Let's look at a few ways
   1.209 +that we can propagate this change into other repositories.
   1.210 +
   1.211 +\subsection{Pulling changes from another repository}
   1.212 +\label{sec:tour:pull}
   1.213 +
   1.214 +To get started, let's clone our original \dirname{hello} repository,
   1.215 +which does not contain the change we just committed.  We'll call our
   1.216 +temporary repository \dirname{hello-pull}.
   1.217 +\interaction{tour.clone-pull}
   1.218 +
   1.219 +We'll use the \hgcmd{pull} command to bring changes from
   1.220 +\dirname{my-hello} into \dirname{hello-pull}.  However, blindly
   1.221 +pulling unknown changes into a repository is a somewhat scary
   1.222 +prospect.  Mercurial provides the \hgcmd{incoming} command to tell us
   1.223 +what changes the \hgcmd{pull} command \emph{would} pull into the
   1.224 +repository, without actually pulling the changes in.
   1.225 +\interaction{tour.incoming}
   1.226 +(Of course, someone could cause more changesets to appear in the
   1.227 +repository that we ran \hgcmd{incoming} in, before we get a chance to
   1.228 +\hgcmd{pull} the changes, so that we could end up pulling changes that we
   1.229 +didn't expect.)
   1.230 +
   1.231 +Bringing changes into a repository is a simple matter of running the
   1.232 +\hgcmd{pull} command, and telling it which repository to pull from.
   1.233 +\interaction{tour.pull}
   1.234 +As you can see from the before-and-after output of \hgcmd{tip}, we
   1.235 +have successfully pulled changes into our repository.  There remains
   1.236 +one step before we can work with those changes.
   1.237 +
   1.238 +\section{Updating the working directory}
   1.239 +
   1.240 +We have so far glossed over the relatioship between a repository and
   1.241 +its working directory.  The \hgcmd{pull} command that we ran in
   1.242 +section~\ref{sec:tour:pull} brought changes into the repository, but
   1.243 +if we check, there's no sign of those changes in the working
   1.244 +directory.  This is because \hgcmd{pull} does not (by default) touch
   1.245 +the working directory.  Instead, we use the \hgcmd{update} command to
   1.246 +do this.
   1.247 +\interaction{tour.update}
   1.248 +
   1.249 +It might seem a bit strange that \hgcmd{pull} doesn't update the
   1.250 +working directory automatically.  There's actually a good reason for
   1.251 +this: you can use \hgcmd{update} to update the working directory to
   1.252 +the state it was in at \emph{any revision} in the history of the
   1.253 +repository.  If you had the working directory updated to an old
   1.254 +revision---to hunt down the origin of a bug, say---and ran a
   1.255 +\hgcmd{pull} which automatically updated the working directory to a
   1.256 +new revision, you might not be terribly happy.
   1.257 +
   1.258 +However, since pull-then-update is such a common thing to do,
   1.259 +Mercurial lets you combine the two by passing the \hgopt{pull}{-u}
   1.260 +option to \hgcmd{pull}.
   1.261 +\begin{codesample2}
   1.262 +  hg pull -u
   1.263 +\end{codesample2}
   1.264 +
   1.265 +To find out what revision the working directory is at, use the
   1.266 +\hgcmd{parents} command.
   1.267 +\interaction{tour.parents}
   1.268 +To update the working directory to a particular revision, give a
   1.269 +revision number or changeset~ID to the \hgcmd{update} command.
   1.270 +\interaction{tour.older}
   1.271 +If you omit an explicit revision, \hgcmd{update} will update to the
   1.272 +tip revision.
   1.273 +
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