大多数时候，你会使用checkout从版本库取出一个新拷贝开始使用Subversion，这样会在本机创建一个项目的“本地拷贝”，这个拷贝包括了命令行指定版本库中的HEAD(最新的)版本：
$ svn checkout http://svn.collab.net/repos/svn/trunk A trunk/Makefile.in A trunk/ac-helpers A trunk/ac-helpers/install.sh A trunk/ac-helpers/install-sh A trunk/build.conf … Checked out revision 8810.
尽管上面的例子取出了trunk目录，你也完全可以通过输入特定URL取出任意深度的子目录：
$ svn checkout \
http://svn.collab.net/repos/svn/trunk/subversion/tests/cmdline/
A cmdline/revert_tests.py
A cmdline/diff_tests.py
A cmdline/autoprop_tests.py
A cmdline/xmltests
A cmdline/xmltests/svn-test.sh
…
Checked out revision 8810.
Since Subversion uses a “copy-modify-merge” model instead of “lock-modify-unlock” (see “版本模型”一节), you can start right in making changes to the files and directories in your working copy. Your working copy is just like any other collection of files and directories on your system. You can edit and change them, move them around, even delete the entire working copy and forget about it.
While your working copy is “just like any other collection of files and directories on your system,” you can edit files at will, but you must tell Subversion about everything else that you do. For example, if you want to copy or move an item in a working copy, you should use svn copy or svn move instead of the copy and move commands provided by your operating system. We'll talk more about them later in this chapter.
Unless you're ready to commit the addition of a new file or directory or changes to existing ones, there's no need to further notify the Subversion server that you've done anything.
因为你可以使用版本库的URL作为唯一参数取出一个工作拷贝，你也可以在版本库URL之后指定一个目录，这样会将你的工作目录放到你的新目录，举个例子：
$ svn checkout http://svn.collab.net/repos/svn/trunk subv A subv/Makefile.in A subv/ac-helpers A subv/ac-helpers/install.sh A subv/ac-helpers/install-sh A subv/build.conf … Checked out revision 8810.
这样将把你的工作拷贝放到subv而不是和前面那样放到trunk，如果subv不存在，将会自动创建。
When you perform a Subversion operation that requires you to authenticate, by default Subversion caches your authentication credentials on disk. This is done for convenience, so that you don't have to continually re-enter your password for future operations. If you're concerned about caching your Subversion passwords, [3] you can disable caching either permanently or on a case-by-case basis.
To disable password caching for a particular one-time
command, pass the --no-auth-cache option on
the command line. To permanently disable caching, you can add
the line store-passwords = no to your local
machine's Subversion configuration file. See “客户端凭证缓存”一节 for
details.
Since Subversion caches auth credentials by default (both
username and password), it conveniently remembers who you were
acting as the last time you modified you working copy. But
sometimes that's not helpful—particularly if you're
working in a shared working copy such as a system
configuration directory or a webserver document root. In this
case, just pass the --username option on the
command line, and Subversion will attempt to authenticate as
that user, prompting you for a password if necessary.
[3] Of course, you're not terribly worried—first because you know that you can't really delete anything from Subversion and, secondly, because your Subversion password isn't the same as any of the other 3 million passwords you have, right? Right?