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<div class="sect1" title="Working Without a Working Copy">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="svn.advanced.working-without-a-wc"></a>Working Without a Working Copy</h2>
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<p>As we described in <a class="xref" href="svn.basic.in-action.html#svn.basic.in-action.wc" title="Subversion Working Copies">the section called “Subversion Working Copies”</a>, the Subversion working copy is a sort of staging area where
a user can privately make changes to his or her versioned data
and then—when those changes are complete and ready for
sharing with others—commit them to the repository. It
should come as no surprise, then, that most of the interaction
you will have with Subversion will be in the form of asking your
Subversion client to do <span class="emphasis"><em>something</em></span> to one or
more items in a local working copy. Even for those operations
which don't manipulate the working copy data itself (such
as <span class="command"><strong>svn log</strong></span>), it's often just easier to use a
working copy file or directory as a convenient target for that
operation.</p>
<p>Clearly, the typical approach to making changes to
your versioned data is via commits from a Subversion working
copy. Fortunately, it's not the only way. Users of Subversion
who need to make relatively simple changes to their versioned
data can do so without the overhead of checking out a working
copy. We'll cover some of those supported operations in this
section.</p>
<div class="sect2" title="Remote command-line client operations">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="svn.advanced.working-without-a-wc.svn"></a>Remote command-line client operations</h3>
</div>
</div>
</div>
<p>The Subversion command-line client supports a number of
operations which can be performed directly against repository
URLs in order to make simple changes without a working copy.
Some of these are described elsewhere in this book, but we
provide an exhaustive list of them here for your
convenience.</p>
<p>Perhaps the most obvious remote commit-like operation is
the <span class="command"><strong>svn import</strong></span> command. We describe that
command in <a class="xref" href="svn.tour.importing.html#svn.tour.importing.import" title="Importing Files and Directories">the section called “Importing Files and Directories”</a> as
part of explaining how you can easily get a whole tree of
unversioned information into your Subversion repository so you
can start doing version-controlled operations on it.</p>
<p>The <span class="command"><strong>svn mkdir</strong></span> and <span class="command"><strong>svn
delete</strong></span> commands, when used with URL targets, are
also remote commit-type operations. These allow the user to
create one or more new versioned directories or remove
(recursively) one or more versioned files or directories,
respectively, without the use of a working copy. Each time
you issue one of these commands, the client communicates with
the server in a way that's similar to how it would describe
the commit of a directory added or of an item removed from the
working copy. If there's no problem or conflict detected with
the requested operation, the server commits the additions or
removals in a single new revision.</p>
<p>You can use <span class="command"><strong>svn copy</strong></span> or <span class="command"><strong>svn
move</strong></span> with two URLs—a copy/move source and a
destination—to commit a copies and moves of files and
directories directly in the repository. These operations tend
to be some of the most expensive ones when performed within a
working copy, but they complete in constant time when
performed remotely using repository URLs. In fact,
the <span class="command"><strong>svn copy</strong></span> remote operation is commonly
used to create branches in Subversion, as we discuss later in
<a class="xref" href="svn.branchmerge.using.html#svn.branchmerge.using.create" title="Creating a Branch">the section called “Creating a Branch”</a>.</p>
<p>As with the regular <span class="command"><strong>svn commit</strong></span> command,
you can supply a log message with any of these commands we've
discussed so far to describe the changes you're making. Use
the <code class="option">--file (-F)</code> or <code class="option">--message
(-m)</code> option, or otherwise allow the client to prompt
you for the log message.</p>
<p>Finally, there are a number of operations related to
unversioned revision properties which can be performed
directly against the repository. In fact, revision properties
are somewhat unique in this context, as they aren't stored in
the working copy and therefore <span class="emphasis"><em>must</em></span> be
modified without working copy interaction. See
<a class="xref" href="svn.advanced.props.html" title="Properties">the section called “Properties”</a> for a more detailed
description of how to manage properties in Subversion.</p>
</div>
<div class="sect2" title="Using svnmucc">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="svn.advanced.working-without-a-wc.svnmucc"></a>Using svnmucc</h3>
</div>
</div>
</div>
<p>One shortcoming of the remote commit operation support
offered in the command-line client is that you are essentially
limited to one operation—or, really, one type of
operation—per commit. For example, it's perfectly
natural and supported to, say, use <span class="command"><strong>svn
delete</strong></span> followed by <span class="command"><strong>svn mkdir</strong></span>
within a working copy to replace an existing versioned
directory with a brand new one. When you commit the results
of those operations, a single new revision is created in the
repository, and that revision carries the full replacement of
your directory. You can't really do the same thing as remote
operations using the command-line client while still
preserving the it-happened-in-a-single-revision-ness of the
change—<span class="command"><strong>svn
delete <em class="replaceable"><code>URL</code></em></strong></span> would create a
new revision that removed the directory; <span class="command"><strong>svn
mkdir <em class="replaceable"><code>URL</code></em></strong></span> would generate
a second revision for the directory's re-creation.</p>
<p>Fortunately, Subversion provides a separate tool which
exists solely to allow users to string together a set of
remote operations and commit them as one atomic change. That
tool is the <span class="command"><strong>svnmucc</strong></span> tool—the
Subversion Multiple URL Command Client:</p>
<div class="informalexample">
<pre class="screen">
$ svnmucc --help
Subversion multiple URL command client
usage: svnmucc ACTION...
Perform one or more Subversion repository URL-based ACTIONs, committing
the result as a (single) new revision.
Actions:
cp REV URL1 URL2 : copy URL1@REV to URL2
mkdir URL : create new directory URL
mv URL1 URL2 : move URL1 to URL2
rm URL : delete URL
put SRC-FILE URL : add or modify file URL with contents copied from
SRC-FILE (use "-" to read from standard input)
propset NAME VAL URL : set property NAME on URL to value VAL
propsetf NAME VAL URL : set property NAME on URL to value from file VAL
propdel NAME URL : delete property NAME from URL
…
</pre>
</div>
<p><span class="command"><strong>svnmucc</strong></span> has been a part of the Subversion
project's source code tree for many years
(as <span class="command"><strong>mucc</strong></span> for most of that time), but it was
only in Subversion 1.8 that it become a fully supported member
of the Subversion command-line tool suite.</p>
<p>The <span class="command"><strong>svnmucc</strong></span> tool can perform any
transformation on your versioned data that <span class="command"><strong>svn</strong></span>
itself can. But unlike <span class="command"><strong>svn</strong></span>, the functionality
that <span class="command"><strong>svnmucc</strong></span> offers isn't broken up into
subcommands. Rather, you provide a list of actions and
operands in a single command line (or from a file stream, via
the <code class="option">--extra-args (-X)</code> option). Some of the
actions supported by <span class="command"><strong>svnmucc</strong></span> mimic those of
the command-line client. You'll notice in the previous
command output actions such as <code class="literal">cp</code>,
<code class="literal">mkdir</code>, <code class="literal">mv</code>,
and <code class="literal">rm</code>, all of which are very similar to
the commands we mentioned in
<a class="xref" href="svn.advanced.working-without-a-wc.html#svn.advanced.working-without-a-wc.svn" title="Remote command-line client operations">the section called “Remote command-line client operations”</a>. But
remember, the key difference here is that you can use any
number of these actions together in a single command
invocation, resulting in a single committed revision in the
repository.</p>
<p>Let's take our previous example of trying to simply
replace a remote directory. Using <span class="command"><strong>svnmucc</strong></span>,
you would accomplish this as follows:</p>
<div class="informalexample">
<pre class="screen">
$ svnmucc rm http://svn.example.com/projects/sandbox \
mkdir http://svn.example.com/projects/sandbox \
-m "Replace my old sandbox with a fresh new one."
r22 committed by harry at 2013-01-15T21:45:26.442865Z
$
</pre>
</div>
<p>As you can see, <span class="command"><strong>svnmucc</strong></span> accomplished in
a single revision what <span class="command"><strong>svn</strong></span>—without
the benefit of a working copy—required two revisions to
complete.</p>
<div class="warning" title="Warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top" width="25">
<img alt="[Warning]" src="images/warning.png" />
</td>
<th align="left">Warning</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Another difference between <span class="command"><strong>svnmucc</strong></span>
and <span class="command"><strong>svn</strong></span> is that the former currently will
not prompt you for a commit log message if you fail to
supply one via the command line. Rather, it will use a
stock (that is, relatively valueless) log message.</p>
</td>
</tr>
</table>
</div>
<p>The <span class="command"><strong>svnmucc</strong></span> tool is not limited to
merely remixing actions that <span class="command"><strong>svn</strong></span> itself can
perform. It introduces some additional functionality not
found in the command-line client. For example, you can use
the <span class="command"><strong>put</strong></span> action to add or modify a file in
the repository, copying the file's intended new contents from
either a file on your local machine or from data piped in via
standard input. The tool also offers <span class="command"><strong>propset</strong></span>,
<span class="command"><strong>propsetf</strong></span>, and <span class="command"><strong>propdel</strong></span>
actions, useful for setting properties on versioned files and
directories (explicitly, or by copying the property's value
from a local file) and for deleting properties on the same.
Those actions are unsupported in the command-line client at
this time.</p>
<p>At this point, though, it seems prudent to discuss the
difference between what <span class="emphasis"><em>can</em></span> be done
with <span class="command"><strong>svnmucc</strong></span> and what
<span class="emphasis"><em>should</em></span> be done. A pair of notable quotes
comes to mind:</p>
<div class="blockquote">
<table border="0" width="100%" cellspacing="0" cellpadding="0" class="blockquote" summary="Block quote">
<tr>
<td width="10%" valign="top"> </td>
<td width="80%" valign="top">
<p>
<span class="quote">“<span class="quote">To whom much has been given, much will be
expected.</span>”</span>
</p>
</td>
<td width="10%" valign="top"> </td>
</tr>
<tr>
<td width="10%" valign="top"> </td>
<td colspan="2" align="right" valign="top">--<span class="attribution">Jesus</span></td>
</tr>
</table>
</div>
<div class="blockquote">
<table border="0" width="100%" cellspacing="0" cellpadding="0" class="blockquote" summary="Block quote">
<tr>
<td width="10%" valign="top"> </td>
<td width="80%" valign="top">
<p>
<span class="quote">“<span class="quote">With great power comes great
responsibility.</span>”</span>
</p>
</td>
<td width="10%" valign="top"> </td>
</tr>
<tr>
<td width="10%" valign="top"> </td>
<td colspan="2" align="right" valign="top">--<span class="attribution">"Spiderman" Peter Parker's Uncle Ben</span></td>
</tr>
</table>
</div>
<p>Inherent in working-copy-less modifications is the loss of
the very conflict detection safeguards which make the use of a
working copy so valuable. When using <span class="command"><strong>svn</strong></span>
in the typical way, changes are committed to the server
against a specific base version of a file or directory so that
you don't inadvertently overwrite contemporary changes made to
the same item by another team member. The server knows what
version of the file you had before you changed it, and it
knows if other folks have changed that same file since that
revision was created. That's all the information the server
needs to deny your commit when it would clobber someone else's
change, forcing you to integrate their change into your
working copy and reconsider your own change. Because there is
no working copy in the mix here, <span class="command"><strong>svnmucc</strong></span>
really gives you the power to bypass those safeguards and to
act as if the current state of the repository is precisely the
base state against which you are working. But hopefully it is
obvious to you that this is not a power you should cavalierly
wield.</p>
<p>Fortunately, <span class="command"><strong>svnmucc</strong></span> allows you to be
more conservative in the way you use the tool. In order to
provide a safety mechanism similar to what is offered by the
use of a working copy, <span class="command"><strong>svnmucc</strong></span> offers
a <code class="option">--revision (-r)</code> option. With this option,
you can manually specify a base revision for the changes you
are attempting to commit. The base revision you choose
is ideally the most recent revision in your repository of
which you can reasonably claim knowledge.</p>
<div class="warning" title="Warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top" width="25">
<img alt="[Warning]" src="images/warning.png" />
</td>
<th align="left">Warning</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Users are strongly encouraged to use, and to use
correctly, the <code class="option">--revision (-r)</code> option
to <span class="command"><strong>svnmucc</strong></span>.</p>
</td>
</tr>
</table>
</div>
<p>Proper use of the <span class="command"><strong>svnmucc put</strong></span> action
best demonstrates how this <code class="option">--revision (-r)</code>
option should be used. Say Harry wishes to change the
contents of a versioned <code class="filename">README</code> file
without bothering with a full checkout of a working copy.
(We'll assume that there is no other value in using a working
copy for this operation, such as the presence of scripts Harry
should run in advance of his commit to verify that it's a
reasonable one.) The first decision he has to make is which
revision of the file he wants to work with. Typically, users
wish to modify the most recent version of a file. So Harry
queries the revision in which the file was last modified, and
then uses that revision to fetch the contents of the file into
a temporary local file:</p>
<div class="informalexample">
<pre class="screen">
$ svn info http://svn.example.com/projects/sandbox/README
Path: README
URL: http://svn.example.com/projects/sandbox/README
Relative URL: ^/sandbox/README
Repository Root: http://svn.example.com/projects
Repository UUID: 13f79535-47bb-0310-9956-ffa450edef68
Revision: 22
Node Kind: file
Last Changed Author: sally
Last Changed Rev: 14
Last Changed Date: 2012-09-02 10:34:09 -0400 (Sun, 02 Sep 2012)
$ svn cat -r 14 http://svn.example.com/projects/sandbox/README \
> README.tmpfile
$
</pre>
</div>
<p>Harry now has a copy of the <code class="filename">README</code>
file as it looked when it it was last modified. He makes the
edits he wishes to make to this copy of the file. Naturally,
when he's finished, he wishes to then commit those changes to
the repository.</p>
<p>Now, if Harry naively uses <strong class="userinput"><code>svnmucc put
…</code></strong> at this point to replace the contents of
<code class="filename">README</code> in the repository with his locally
modified contents, he has just abused the power
that <span class="command"><strong>svnmucc</strong></span> affords. What if, just
microseconds prior to his commit, Sally had also modified
the <code class="filename">README</code> file? As with the
<span class="command"><strong>svn</strong></span> program, <span class="command"><strong>svnmucc</strong></span>
won't attempt some sort of server-side content merge in order
to preserve both users' changes. Rather,
<span class="command"><strong>svnmucc</strong></span> will happily replace the current
latest version of the file with the contents specified. Harry
will be oblivious. Sally will be livid.</p>
<div class="informalexample">
<pre class="screen">
$ svnmucc put README.tmpfile \
http://svn.example.com/projects/sandbox/README \
-m "Tweak the README file."
r24 committed by harry at 2013-01-21T16:21:23.100133Z
$
Message from sally@shell.example.com on pts/2 at 16:26 ...
We need to talk. Now.
EOF
</pre>
</div>
<p>Harry should instead recall the revision he originally
used as the revision on which to base his changes, supplying
that revision to <span class="command"><strong>svnmucc</strong></span> via
the <code class="option">--revision (-r)</code> option, and thus giving
the server the opportunity to bounce his commit if, by his own
(perhaps ignorant) admission, he's attempting to modify an
out-of-date item:</p>
<div class="informalexample">
<pre class="screen">
$ svnmucc -r 14 put README.tmpfile \
http://svn.example.com/projects/sandbox/README \
-m "Tweak the README file."
svnmucc: E170004: Item '/sandbox/README' is out of date
$
</pre>
</div>
<p>Like other <span class="command"><strong>svnmucc</strong></span> options,
the <code class="option">--revision (-r)</code> option operates at a
scope global to the whole command—every action specified
in that command. This enables you to have the same sort of
safeguards you would have if you had checked out a working
copy of your entire repository (and thus had a working copy
entirely at a single uniform revision), made changes to that
working copy, and then committed all those changes at
once.</p>
<p>As you can see, <span class="command"><strong>svnmucc</strong></span> is a handy
addition to the Subversion user's tool chest. For a complete
reference of this tool's offerings, see
<a class="xref" href="svn.ref.svnmucc.html" title="svnmucc Reference—Subversion Multiple URL Command Client">svnmucc Reference—Subversion Multiple URL Command Client</a>.</p>
</div>
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<p>You are reading <em>Version Control with Subversion</em> (for
Subversion 1.8), by Ben Collins-Sussman, Brian W. Fitzpatrick,
and C. Michael Pilato.</p>
<p>This work is licensed under
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<p>To submit comments, corrections, or other contributions to the
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