hgbook
view en/ch02-tour-basic.tex @ 559:b90b024729f1
WIP DocBook snapshot that all compiles. Mirabile dictu!
| author | Bryan O'Sullivan <bos@serpentine.com> |
|---|---|
| date | Wed Feb 18 00:22:09 2009 -0800 (2009-02-18) |
| parents | 5cd47f721686 |
| children |
line source
1 \chapter{A tour of Mercurial: the basics}
2 \label{chap:tour-basic}
4 \section{Installing Mercurial on your system}
5 \label{sec:tour:install}
7 Prebuilt binary packages of Mercurial are available for every popular
8 operating system. These make it easy to start using Mercurial on your
9 computer immediately.
11 \subsection{Linux}
13 Because each Linux distribution has its own packaging tools, policies,
14 and rate of development, it's difficult to give a comprehensive set of
15 instructions on how to install Mercurial binaries. The version of
16 Mercurial that you will end up with can vary depending on how active
17 the person is who maintains the package for your distribution.
19 To keep things simple, I will focus on installing Mercurial from the
20 command line under the most popular Linux distributions. Most of
21 these distributions provide graphical package managers that will let
22 you install Mercurial with a single click; the package name to look
23 for is \texttt{mercurial}.
25 \begin{itemize}
26 \item[Debian]
27 \begin{codesample4}
28 apt-get install mercurial
29 \end{codesample4}
31 \item[Fedora Core]
32 \begin{codesample4}
33 yum install mercurial
34 \end{codesample4}
36 \item[Gentoo]
37 \begin{codesample4}
38 emerge mercurial
39 \end{codesample4}
41 \item[OpenSUSE]
42 \begin{codesample4}
43 yum install mercurial
44 \end{codesample4}
46 \item[Ubuntu] Ubuntu's Mercurial package is based on Debian's. To
47 install it, run the following command.
48 \begin{codesample4}
49 apt-get install mercurial
50 \end{codesample4}
51 The Ubuntu package for Mercurial tends to lag behind the Debian
52 version by a considerable time margin (at the time of writing, seven
53 months), which in some cases will mean that on Ubuntu, you may run
54 into problems that have since been fixed in the Debian package.
55 \end{itemize}
57 \subsection{Solaris}
59 SunFreeWare, at \url{http://www.sunfreeware.com}, is a good source for a
60 large number of pre-built Solaris packages for 32 and 64 bit Intel and
61 Sparc architectures, including current versions of Mercurial.
63 \subsection{Mac OS X}
65 Lee Cantey publishes an installer of Mercurial for Mac OS~X at
66 \url{http://mercurial.berkwood.com}. This package works on both
67 Intel-~and Power-based Macs. Before you can use it, you must install
68 a compatible version of Universal MacPython~\cite{web:macpython}. This
69 is easy to do; simply follow the instructions on Lee's site.
71 It's also possible to install Mercurial using Fink or MacPorts,
72 two popular free package managers for Mac OS X. If you have Fink,
73 use \command{sudo apt-get install mercurial-py25}. If MacPorts,
74 \command{sudo port install mercurial}.
76 \subsection{Windows}
78 Lee Cantey publishes an installer of Mercurial for Windows at
79 \url{http://mercurial.berkwood.com}. This package has no external
80 dependencies; it ``just works''.
82 \begin{note}
83 The Windows version of Mercurial does not automatically convert line
84 endings between Windows and Unix styles. If you want to share work
85 with Unix users, you must do a little additional configuration
86 work. XXX Flesh this out.
87 \end{note}
89 \section{Getting started}
91 To begin, we'll use the \hgcmd{version} command to find out whether
92 Mercurial is actually installed properly. The actual version
93 information that it prints isn't so important; it's whether it prints
94 anything at all that we care about.
95 \interaction{tour.version}
97 \subsection{Built-in help}
99 Mercurial provides a built-in help system. This is invaluable for those
100 times when you find yourself stuck trying to remember how to run a
101 command. If you are completely stuck, simply run \hgcmd{help}; it
102 will print a brief list of commands, along with a description of what
103 each does. If you ask for help on a specific command (as below), it
104 prints more detailed information.
105 \interaction{tour.help}
106 For a more impressive level of detail (which you won't usually need)
107 run \hgcmdargs{help}{\hggopt{-v}}. The \hggopt{-v} option is short
108 for \hggopt{--verbose}, and tells Mercurial to print more information
109 than it usually would.
111 \section{Working with a repository}
113 In Mercurial, everything happens inside a \emph{repository}. The
114 repository for a project contains all of the files that ``belong to''
115 that project, along with a historical record of the project's files.
117 There's nothing particularly magical about a repository; it is simply
118 a directory tree in your filesystem that Mercurial treats as special.
119 You can rename or delete a repository any time you like, using either the
120 command line or your file browser.
122 \subsection{Making a local copy of a repository}
124 \emph{Copying} a repository is just a little bit special. While you
125 could use a normal file copying command to make a copy of a
126 repository, it's best to use a built-in command that Mercurial
127 provides. This command is called \hgcmd{clone}, because it creates an
128 identical copy of an existing repository.
129 \interaction{tour.clone}
130 If our clone succeeded, we should now have a local directory called
131 \dirname{hello}. This directory will contain some files.
132 \interaction{tour.ls}
133 These files have the same contents and history in our repository as
134 they do in the repository we cloned.
136 Every Mercurial repository is complete, self-contained, and
137 independent. It contains its own private copy of a project's files
138 and history. A cloned repository remembers the location of the
139 repository it was cloned from, but it does not communicate with that
140 repository, or any other, unless you tell it to.
142 What this means for now is that we're free to experiment with our
143 repository, safe in the knowledge that it's a private ``sandbox'' that
144 won't affect anyone else.
146 \subsection{What's in a repository?}
148 When we take a more detailed look inside a repository, we can see that
149 it contains a directory named \dirname{.hg}. This is where Mercurial
150 keeps all of its metadata for the repository.
151 \interaction{tour.ls-a}
153 The contents of the \dirname{.hg} directory and its subdirectories are
154 private to Mercurial. Every other file and directory in the
155 repository is yours to do with as you please.
157 To introduce a little terminology, the \dirname{.hg} directory is the
158 ``real'' repository, and all of the files and directories that coexist
159 with it are said to live in the \emph{working directory}. An easy way
160 to remember the distinction is that the \emph{repository} contains the
161 \emph{history} of your project, while the \emph{working directory}
162 contains a \emph{snapshot} of your project at a particular point in
163 history.
165 \section{A tour through history}
167 One of the first things we might want to do with a new, unfamiliar
168 repository is understand its history. The \hgcmd{log} command gives
169 us a view of history.
170 \interaction{tour.log}
171 By default, this command prints a brief paragraph of output for each
172 change to the project that was recorded. In Mercurial terminology, we
173 call each of these recorded events a \emph{changeset}, because it can
174 contain a record of changes to several files.
176 The fields in a record of output from \hgcmd{log} are as follows.
177 \begin{itemize}
178 \item[\texttt{changeset}] This field has the format of a number,
179 followed by a colon, followed by a hexadecimal string. These are
180 \emph{identifiers} for the changeset. There are two identifiers
181 because the number is shorter and easier to type than the hex
182 string.
183 \item[\texttt{user}] The identity of the person who created the
184 changeset. This is a free-form field, but it most often contains a
185 person's name and email address.
186 \item[\texttt{date}] The date and time on which the changeset was
187 created, and the timezone in which it was created. (The date and
188 time are local to that timezone; they display what time and date it
189 was for the person who created the changeset.)
190 \item[\texttt{summary}] The first line of the text message that the
191 creator of the changeset entered to describe the changeset.
192 \end{itemize}
193 The default output printed by \hgcmd{log} is purely a summary; it is
194 missing a lot of detail.
196 Figure~\ref{fig:tour-basic:history} provides a graphical representation of
197 the history of the \dirname{hello} repository, to make it a little
198 easier to see which direction history is ``flowing'' in. We'll be
199 returning to this figure several times in this chapter and the chapter
200 that follows.
202 \begin{figure}[ht]
203 \centering
204 \grafix{tour-history}
205 \caption{Graphical history of the \dirname{hello} repository}
206 \label{fig:tour-basic:history}
207 \end{figure}
209 \subsection{Changesets, revisions, and talking to other people}
211 As English is a notoriously sloppy language, and computer science has
212 a hallowed history of terminological confusion (why use one term when
213 four will do?), revision control has a variety of words and phrases
214 that mean the same thing. If you are talking about Mercurial history
215 with other people, you will find that the word ``changeset'' is often
216 compressed to ``change'' or (when written) ``cset'', and sometimes a
217 changeset is referred to as a ``revision'' or a ``rev''.
219 While it doesn't matter what \emph{word} you use to refer to the
220 concept of ``a~changeset'', the \emph{identifier} that you use to
221 refer to ``a~\emph{specific} changeset'' is of great importance.
222 Recall that the \texttt{changeset} field in the output from
223 \hgcmd{log} identifies a changeset using both a number and a
224 hexadecimal string.
225 \begin{itemize}
226 \item The revision number is \emph{only valid in that repository},
227 \item while the hex string is the \emph{permanent, unchanging identifier} that will always identify that exact changeset in
228 \emph{every} copy of the repository.
229 \end{itemize}
230 This distinction is important. If you send someone an email talking
231 about ``revision~33'', there's a high likelihood that their
232 revision~33 will \emph{not be the same} as yours. The reason for this
233 is that a revision number depends on the order in which changes
234 arrived in a repository, and there is no guarantee that the same
235 changes will happen in the same order in different repositories.
236 Three changes $a,b,c$ can easily appear in one repository as $0,1,2$,
237 while in another as $1,0,2$.
239 Mercurial uses revision numbers purely as a convenient shorthand. If
240 you need to discuss a changeset with someone, or make a record of a
241 changeset for some other reason (for example, in a bug report), use
242 the hexadecimal identifier.
244 \subsection{Viewing specific revisions}
246 To narrow the output of \hgcmd{log} down to a single revision, use the
247 \hgopt{log}{-r} (or \hgopt{log}{--rev}) option. You can use either a
248 revision number or a long-form changeset identifier, and you can
249 provide as many revisions as you want. \interaction{tour.log-r}
251 If you want to see the history of several revisions without having to
252 list each one, you can use \emph{range notation}; this lets you
253 express the idea ``I want all revisions between $a$ and $b$,
254 inclusive''.
255 \interaction{tour.log.range}
256 Mercurial also honours the order in which you specify revisions, so
257 \hgcmdargs{log}{-r 2:4} prints $2,3,4$ while \hgcmdargs{log}{-r 4:2}
258 prints $4,3,2$.
260 \subsection{More detailed information}
262 While the summary information printed by \hgcmd{log} is useful if you
263 already know what you're looking for, you may need to see a complete
264 description of the change, or a list of the files changed, if you're
265 trying to decide whether a changeset is the one you're looking for.
266 The \hgcmd{log} command's \hggopt{-v} (or \hggopt{--verbose})
267 option gives you this extra detail.
268 \interaction{tour.log-v}
270 If you want to see both the description and content of a change, add
271 the \hgopt{log}{-p} (or \hgopt{log}{--patch}) option. This displays
272 the content of a change as a \emph{unified diff} (if you've never seen
273 a unified diff before, see section~\ref{sec:mq:patch} for an overview).
274 \interaction{tour.log-vp}
276 \section{All about command options}
278 Let's take a brief break from exploring Mercurial commands to discuss
279 a pattern in the way that they work; you may find this useful to keep
280 in mind as we continue our tour.
282 Mercurial has a consistent and straightforward approach to dealing
283 with the options that you can pass to commands. It follows the
284 conventions for options that are common to modern Linux and Unix
285 systems.
286 \begin{itemize}
287 \item Every option has a long name. For example, as we've already
288 seen, the \hgcmd{log} command accepts a \hgopt{log}{--rev} option.
289 \item Most options have short names, too. Instead of
290 \hgopt{log}{--rev}, we can use \hgopt{log}{-r}. (The reason that
291 some options don't have short names is that the options in question
292 are rarely used.)
293 \item Long options start with two dashes (e.g.~\hgopt{log}{--rev}),
294 while short options start with one (e.g.~\hgopt{log}{-r}).
295 \item Option naming and usage is consistent across commands. For
296 example, every command that lets you specify a changeset~ID or
297 revision number accepts both \hgopt{log}{-r} and \hgopt{log}{--rev}
298 arguments.
299 \end{itemize}
300 In the examples throughout this book, I use short options instead of
301 long. This just reflects my own preference, so don't read anything
302 significant into it.
304 Most commands that print output of some kind will print more output
305 when passed a \hggopt{-v} (or \hggopt{--verbose}) option, and less
306 when passed \hggopt{-q} (or \hggopt{--quiet}).
308 \section{Making and reviewing changes}
310 Now that we have a grasp of viewing history in Mercurial, let's take a
311 look at making some changes and examining them.
313 The first thing we'll do is isolate our experiment in a repository of
314 its own. We use the \hgcmd{clone} command, but we don't need to
315 clone a copy of the remote repository. Since we already have a copy
316 of it locally, we can just clone that instead. This is much faster
317 than cloning over the network, and cloning a local repository uses
318 less disk space in most cases, too.
319 \interaction{tour.reclone}
320 As an aside, it's often good practice to keep a ``pristine'' copy of a
321 remote repository around, which you can then make temporary clones of
322 to create sandboxes for each task you want to work on. This lets you
323 work on multiple tasks in parallel, each isolated from the others
324 until it's complete and you're ready to integrate it back. Because
325 local clones are so cheap, there's almost no overhead to cloning and
326 destroying repositories whenever you want.
328 In our \dirname{my-hello} repository, we have a file
329 \filename{hello.c} that contains the classic ``hello, world'' program.
330 Let's use the ancient and venerable \command{sed} command to edit this
331 file so that it prints a second line of output. (I'm only using
332 \command{sed} to do this because it's easy to write a scripted example
333 this way. Since you're not under the same constraint, you probably
334 won't want to use \command{sed}; simply use your preferred text editor to
335 do the same thing.)
336 \interaction{tour.sed}
338 Mercurial's \hgcmd{status} command will tell us what Mercurial knows
339 about the files in the repository.
340 \interaction{tour.status}
341 The \hgcmd{status} command prints no output for some files, but a line
342 starting with ``\texttt{M}'' for \filename{hello.c}. Unless you tell
343 it to, \hgcmd{status} will not print any output for files that have
344 not been modified.
346 The ``\texttt{M}'' indicates that Mercurial has noticed that we
347 modified \filename{hello.c}. We didn't need to \emph{inform}
348 Mercurial that we were going to modify the file before we started, or
349 that we had modified the file after we were done; it was able to
350 figure this out itself.
352 It's a little bit helpful to know that we've modified
353 \filename{hello.c}, but we might prefer to know exactly \emph{what}
354 changes we've made to it. To do this, we use the \hgcmd{diff}
355 command.
356 \interaction{tour.diff}
358 \section{Recording changes in a new changeset}
360 We can modify files, build and test our changes, and use
361 \hgcmd{status} and \hgcmd{diff} to review our changes, until we're
362 satisfied with what we've done and arrive at a natural stopping point
363 where we want to record our work in a new changeset.
365 The \hgcmd{commit} command lets us create a new changeset; we'll
366 usually refer to this as ``making a commit'' or ``committing''.
368 \subsection{Setting up a username}
370 When you try to run \hgcmd{commit} for the first time, it is not
371 guaranteed to succeed. Mercurial records your name and address with
372 each change that you commit, so that you and others will later be able
373 to tell who made each change. Mercurial tries to automatically figure
374 out a sensible username to commit the change with. It will attempt
375 each of the following methods, in order:
376 \begin{enumerate}
377 \item If you specify a \hgopt{commit}{-u} option to the \hgcmd{commit}
378 command on the command line, followed by a username, this is always
379 given the highest precedence.
380 \item If you have set the \envar{HGUSER} environment variable, this is
381 checked next.
382 \item If you create a file in your home directory called
383 \sfilename{.hgrc}, with a \rcitem{ui}{username} entry, that will be
384 used next. To see what the contents of this file should look like,
385 refer to section~\ref{sec:tour-basic:username} below.
386 \item If you have set the \envar{EMAIL} environment variable, this
387 will be used next.
388 \item Mercurial will query your system to find out your local user
389 name and host name, and construct a username from these components.
390 Since this often results in a username that is not very useful, it
391 will print a warning if it has to do this.
392 \end{enumerate}
393 If all of these mechanisms fail, Mercurial will fail, printing an
394 error message. In this case, it will not let you commit until you set
395 up a username.
397 You should think of the \envar{HGUSER} environment variable and the
398 \hgopt{commit}{-u} option to the \hgcmd{commit} command as ways to
399 \emph{override} Mercurial's default selection of username. For normal
400 use, the simplest and most robust way to set a username for yourself
401 is by creating a \sfilename{.hgrc} file; see below for details.
403 \subsubsection{Creating a Mercurial configuration file}
404 \label{sec:tour-basic:username}
406 To set a user name, use your favourite editor to create a file called
407 \sfilename{.hgrc} in your home directory. Mercurial will use this
408 file to look up your personalised configuration settings. The initial
409 contents of your \sfilename{.hgrc} should look like this.
410 \begin{codesample2}
411 # This is a Mercurial configuration file.
412 [ui]
413 username = Firstname Lastname <email.address@domain.net>
414 \end{codesample2}
415 The ``\texttt{[ui]}'' line begins a \emph{section} of the config file,
416 so you can read the ``\texttt{username = ...}'' line as meaning ``set
417 the value of the \texttt{username} item in the \texttt{ui} section''.
418 A section continues until a new section begins, or the end of the
419 file. Mercurial ignores empty lines and treats any text from
420 ``\texttt{\#}'' to the end of a line as a comment.
422 \subsubsection{Choosing a user name}
424 You can use any text you like as the value of the \texttt{username}
425 config item, since this information is for reading by other people,
426 but for interpreting by Mercurial. The convention that most people
427 follow is to use their name and email address, as in the example
428 above.
430 \begin{note}
431 Mercurial's built-in web server obfuscates email addresses, to make
432 it more difficult for the email harvesting tools that spammers use.
433 This reduces the likelihood that you'll start receiving more junk
434 email if you publish a Mercurial repository on the web.
435 \end{note}
437 \subsection{Writing a commit message}
439 When we commit a change, Mercurial drops us into a text editor, to
440 enter a message that will describe the modifications we've made in
441 this changeset. This is called the \emph{commit message}. It will be
442 a record for readers of what we did and why, and it will be printed by
443 \hgcmd{log} after we've finished committing.
444 \interaction{tour.commit}
446 The editor that the \hgcmd{commit} command drops us into will contain
447 an empty line, followed by a number of lines starting with
448 ``\texttt{HG:}''.
449 \begin{codesample2}
450 \emph{empty line}
451 HG: changed hello.c
452 \end{codesample2}
453 Mercurial ignores the lines that start with ``\texttt{HG:}''; it uses
454 them only to tell us which files it's recording changes to. Modifying
455 or deleting these lines has no effect.
457 \subsection{Writing a good commit message}
459 Since \hgcmd{log} only prints the first line of a commit message by
460 default, it's best to write a commit message whose first line stands
461 alone. Here's a real example of a commit message that \emph{doesn't}
462 follow this guideline, and hence has a summary that is not readable.
463 \begin{codesample2}
464 changeset: 73:584af0e231be
465 user: Censored Person <censored.person@example.org>
466 date: Tue Sep 26 21:37:07 2006 -0700
467 summary: include buildmeister/commondefs. Add an exports and install
468 \end{codesample2}
470 As far as the remainder of the contents of the commit message are
471 concerned, there are no hard-and-fast rules. Mercurial itself doesn't
472 interpret or care about the contents of the commit message, though
473 your project may have policies that dictate a certain kind of
474 formatting.
476 My personal preference is for short, but informative, commit messages
477 that tell me something that I can't figure out with a quick glance at
478 the output of \hgcmdargs{log}{--patch}.
480 \subsection{Aborting a commit}
482 If you decide that you don't want to commit while in the middle of
483 editing a commit message, simply exit from your editor without saving
484 the file that it's editing. This will cause nothing to happen to
485 either the repository or the working directory.
487 If we run the \hgcmd{commit} command without any arguments, it records
488 all of the changes we've made, as reported by \hgcmd{status} and
489 \hgcmd{diff}.
491 \subsection{Admiring our new handiwork}
493 Once we've finished the commit, we can use the \hgcmd{tip} command to
494 display the changeset we just created. This command produces output
495 that is identical to \hgcmd{log}, but it only displays the newest
496 revision in the repository.
497 \interaction{tour.tip}
498 We refer to the newest revision in the repository as the tip revision,
499 or simply the tip.
501 \section{Sharing changes}
503 We mentioned earlier that repositories in Mercurial are
504 self-contained. This means that the changeset we just created exists
505 only in our \dirname{my-hello} repository. Let's look at a few ways
506 that we can propagate this change into other repositories.
508 \subsection{Pulling changes from another repository}
509 \label{sec:tour:pull}
511 To get started, let's clone our original \dirname{hello} repository,
512 which does not contain the change we just committed. We'll call our
513 temporary repository \dirname{hello-pull}.
514 \interaction{tour.clone-pull}
516 We'll use the \hgcmd{pull} command to bring changes from
517 \dirname{my-hello} into \dirname{hello-pull}. However, blindly
518 pulling unknown changes into a repository is a somewhat scary
519 prospect. Mercurial provides the \hgcmd{incoming} command to tell us
520 what changes the \hgcmd{pull} command \emph{would} pull into the
521 repository, without actually pulling the changes in.
522 \interaction{tour.incoming}
523 (Of course, someone could cause more changesets to appear in the
524 repository that we ran \hgcmd{incoming} in, before we get a chance to
525 \hgcmd{pull} the changes, so that we could end up pulling changes that we
526 didn't expect.)
528 Bringing changes into a repository is a simple matter of running the
529 \hgcmd{pull} command, and telling it which repository to pull from.
530 \interaction{tour.pull}
531 As you can see from the before-and-after output of \hgcmd{tip}, we
532 have successfully pulled changes into our repository. There remains
533 one step before we can see these changes in the working directory.
535 \subsection{Updating the working directory}
537 We have so far glossed over the relationship between a repository and
538 its working directory. The \hgcmd{pull} command that we ran in
539 section~\ref{sec:tour:pull} brought changes into the repository, but
540 if we check, there's no sign of those changes in the working
541 directory. This is because \hgcmd{pull} does not (by default) touch
542 the working directory. Instead, we use the \hgcmd{update} command to
543 do this.
544 \interaction{tour.update}
546 It might seem a bit strange that \hgcmd{pull} doesn't update the
547 working directory automatically. There's actually a good reason for
548 this: you can use \hgcmd{update} to update the working directory to
549 the state it was in at \emph{any revision} in the history of the
550 repository. If you had the working directory updated to an old
551 revision---to hunt down the origin of a bug, say---and ran a
552 \hgcmd{pull} which automatically updated the working directory to a
553 new revision, you might not be terribly happy.
555 However, since pull-then-update is such a common thing to do,
556 Mercurial lets you combine the two by passing the \hgopt{pull}{-u}
557 option to \hgcmd{pull}.
558 \begin{codesample2}
559 hg pull -u
560 \end{codesample2}
561 If you look back at the output of \hgcmd{pull} in
562 section~\ref{sec:tour:pull} when we ran it without \hgopt{pull}{-u},
563 you can see that it printed a helpful reminder that we'd have to take
564 an explicit step to update the working directory:
565 \begin{codesample2}
566 (run 'hg update' to get a working copy)
567 \end{codesample2}
569 To find out what revision the working directory is at, use the
570 \hgcmd{parents} command.
571 \interaction{tour.parents}
572 If you look back at figure~\ref{fig:tour-basic:history}, you'll see
573 arrows connecting each changeset. The node that the arrow leads
574 \emph{from} in each case is a parent, and the node that the arrow
575 leads \emph{to} is its child. The working directory has a parent in
576 just the same way; this is the changeset that the working directory
577 currently contains.
579 To update the working directory to a particular revision, give a
580 revision number or changeset~ID to the \hgcmd{update} command.
581 \interaction{tour.older}
582 If you omit an explicit revision, \hgcmd{update} will update to the
583 tip revision, as shown by the second call to \hgcmd{update} in the
584 example above.
586 \subsection{Pushing changes to another repository}
588 Mercurial lets us push changes to another repository, from the
589 repository we're currently visiting. As with the example of
590 \hgcmd{pull} above, we'll create a temporary repository to push our
591 changes into.
592 \interaction{tour.clone-push}
593 The \hgcmd{outgoing} command tells us what changes would be pushed
594 into another repository.
595 \interaction{tour.outgoing}
596 And the \hgcmd{push} command does the actual push.
597 \interaction{tour.push}
598 As with \hgcmd{pull}, the \hgcmd{push} command does not update the
599 working directory in the repository that it's pushing changes into.
600 (Unlike \hgcmd{pull}, \hgcmd{push} does not provide a \texttt{-u}
601 option that updates the other repository's working directory.)
603 What happens if we try to pull or push changes and the receiving
604 repository already has those changes? Nothing too exciting.
605 \interaction{tour.push.nothing}
607 \subsection{Sharing changes over a network}
609 The commands we have covered in the previous few sections are not
610 limited to working with local repositories. Each works in exactly the
611 same fashion over a network connection; simply pass in a URL instead
612 of a local path.
613 \interaction{tour.outgoing.net}
614 In this example, we can see what changes we could push to the remote
615 repository, but the repository is understandably not set up to let
616 anonymous users push to it.
617 \interaction{tour.push.net}
619 %%% Local Variables:
620 %%% mode: latex
621 %%% TeX-master: "00book"
622 %%% End: