In any given working copy, there is a good chance that alongside all those versioned files and directories are other files and directories that are neither versioned nor intended to be. Text editors litter directories with backup files. Software compilers generate intermediate—or even final—files that you typically wouldn't bother to version. And users themselves drop various other files and directories wherever they see fit, often in version control working copies.
It's ludicrous to expect Subversion working copies to be somehow impervious to this kind of clutter and impurity. In fact, Subversion counts it as a feature that its working copies are just typical directories, just like unversioned trees. But these not-to-be-versioned files and directories can cause some annoyance for Subversion users. For example, because the svn add and svn import commands act recursively by default and don't know which files in a given tree you do and don't wish to version, it's easy to accidentally add stuff to version control that you didn't mean to. And because svn status reports, by default, every item of interest in a working copy—including unversioned files and directories—its output can get quite noisy where many of these things exist.
So Subversion provides two ways for telling it which files you would prefer that it simply disregard. One of the ways involves the use of Subversion's runtime configuration system (see 第 1 节 “运行配置区”), and therefore applies to all the Subversion operations that make use of that runtime configuration—generally those performed on a particular computer or by a particular user of a computer. The other way makes use of Subversion's directory property support and is more tightly bound to the versioned tree itself, and therefore affects everyone who has a working copy of that tree. Both of the mechanisms use file patterns (strings of literal and special wildcard characters used to match against filenames) to decide which files to ignore.
The Subversion runtime configuration system provides an option,
global-ignores, whose value is a whitespace-delimited
collection of file patterns. The Subversion client checks these patterns
against the names of the files that are candidates for addition to version
control, as well as to unversioned files that the svn
status command notices. If any file's name matches one of the
patterns, Subversion will basically act as if the file didn't exist at all.
This is really useful for the kinds of files that you almost never want to
version, such as editor backup files such as Emacs' *~
and .*~ files.
When found on a versioned directory, the svn:ignore
property is expected to contain a list of newline-delimited file patterns
that Subversion should use to determine ignorable objects in that same
directory. These patterns do not override those found in the
global-ignores runtime configuration option, but are
instead appended to that list. And it's worth noting again that, unlike the
global-ignores option, the patterns found in the
svn:ignore property apply only to the directory on which
that property is set, and not to any of its subdirectories. The
svn:ignore property is a good way to tell Subversion to
ignore files that are likely to be present in every user's working copy of
that directory, such as compiler output or—to use an example more
appropriate to this book—the HTML, PDF, or PostScript files generated
as the result of a conversion of some source DocBook XML files to a more
legible output format.
![[注意]](images/note.png)
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Subversion's support for ignorable file patterns extends only to the one-time process of adding unversioned files and directories to version control. Once an object is under Subversion's control, the ignore pattern mechanisms no longer apply to it. In other words, don't expect Subversion to avoid committing changes you've made to a versioned file simply because that file's name matches an ignore pattern—Subversion always notices all of its versioned objects. |
The global list of ignore patterns tends to be more a matter of personal
taste and ties more closely to a user's particular tool chain than to the
details of any particular working copy's needs. So, the rest of this
section will focus on the svn:ignore property and its
uses.
假定你的svn status有如下输出：
$ svn status calc M calc/button.c ? calc/calculator ? calc/data.c ? calc/debug_log ? calc/debug_log.1 ? calc/debug_log.2.gz ? calc/debug_log.3.gz
In this example, you have made some property modifications to
button.c, but in your working copy, you also have some
unversioned files: the latest calculator program that
you've compiled from your source code, a source file named
data.c, and a set of debugging output logfiles. Now,
you know that your build system always results in the
calculator program being generated.[16] And you know that your test suite always leaves
those debugging logfiles lying around. These facts are true for all working
copies of this project, not just your own. And you know that you aren't
interested in seeing those things every time you run svn
status, and you are pretty sure that nobody else is interested in
them either. So you use svn propedit svn:ignore calc
to add some ignore patterns to the calc directory.
$ svn propget svn:ignore calc calculator debug_log* $
After you've added this property, you will now have a local property
modification on the calc directory. But notice what
else is different about your svn status output:
$ svn status M calc M calc/button.c ? calc/data.c
Now, all that cruft is missing from the output! Your
calculator compiled program and all those logfiles are
still in your working copy; Subversion just isn't constantly reminding you
that they are present and unversioned. And now with all the uninteresting
noise removed from the display, you are left with more intriguing
items—such as that source code file data.c that
you probably forgot to add to version control.
Of course, this less-verbose report of your working copy status isn't the
only one available. If you actually want to see the ignored files as part
of the status report, you can pass the --no-ignore option
to Subversion:
$ svn status --no-ignore M calc M calc/button.c I calc/calculator ? calc/data.c I calc/debug_log I calc/debug_log.1 I calc/debug_log.2.gz I calc/debug_log.3.gz
As mentioned earlier, the list of file patterns to ignore is also used by
svn add and svn import. Both of these
operations involve asking Subversion to begin managing some set of files and
directories. Rather than force the user to pick and choose which files in a
tree she wishes to start versioning, Subversion uses the ignore
patterns—both the global and the per-directory lists—to
determine which files should not be swept into the version control system as
part of a larger recursive addition or import operation. And here again,
you can use the --no-ignore option to tell Subversion to
disregard its ignores list and operate on all the files and directories
present.
![[提示]](images/tip.png)
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Even if |