一个可选参数，用于显示此命令的参数。
An optional parameter used to display the parameters for this command.
工具栏是在用户需要使用应用程序时，可以控制该程序核心命令的一个可选的固定工具条。
This is an optional fixed bar available to an application at all times, whenever core commands are needed.
您还可以使用该命令基于指定现有分支的可选跟踪更改新建一个分支。
You can also use this command to create a new branch that is based on and optionally tracks changes to a specified existing branch.
db 2 pd是从命令行以一种可选的交互模式执行的。
Db2pd is executed from the command line with an optional interactive mode.
注意，SQL代码和MySQL内部命令的大写是可选的，但是数据库的名称、表和列都对大小写敏感。
Note that capitalization of the SQL code and MySQL internal commands is optional, but names of databases, tables, and columns are case sensitive.
必须提一下，当我们定义manifest时，我们可以在Felix和Equinox命令行上声明可选依赖，这样，当我们两者中任何一个安装之后，我们就可以运行了。
Suffice to say, that when we define our manifest, we can declare optional dependencies on both the Felix and Equinox command line interfaces, so that when we install into either, we'll be able to run.
可选：要查看变更命令。
控制跟踪的主要方法是使用命令行选项 -Xtrace，或者在选项集比较长或复杂的情况下，使用可选的跟踪属性文件。
The primary way you can control trace is by using the -Xtrace option on the command line or you can use the optional trace properties file if the option set is long or complex.
iptables命令的可选match部分指定信息包与规则匹配所应具有的特征（如源和目的地地址、协议等）。
The optional match section of the iptables command specifies the characteristics that a packet should have to match the rule, such as source and destination address, protocol, etc.
此命令还有两个可选属性name和serverUrl 用来指定 Selenium测试的名称和 web应用程序可用的服务器。
This command also has two optional attributes called name and serverUrl to specify the name of the Selenium test and the server where the web application is available.
还包括一个名为JDBCProvider的可配置服务，它可让您使用WebSphereMessageBroker提供的命令定义包括可选安全信息在内的连接详细信息。
Also included is a configurable service called JDBCProvider, which lets you define connection details including optional security information using WebSphere Message Broker supplied commands.
type参数是用于传递所执行的命令，它指定了可选的缓冲区长度。
The type argument communicates the command to perform and is associated with an optional buffer with its length.
sed接受包含任何数量命令的脚本，后面跟着可选的指定输入文件的选项；缺省情况下，它读取标准输入。
Sed takes a script of any number of commands followed by an optional input filespec; by default, it reads standard input.
parameter是一些命令可能需要的可选参数。
The parameter is an optional parameter that some commands may require.
其中command是YQL命令，queryparameter表示服务的可选参数。
Where command is the YQL command and query parameter represents optional parameters to the service.
命令开始处的冒号是可选的，但是最好加上；这么做能够让命令更轻松地在一个(往往很复杂的)autocmd参数清单中定位。
The colon at the start of the command is optional, but it's a good idea to include it; doing so makes the command easier to locate in the (usually complex) argument list of an autocmd.
exec()命令与 shell_exec()相似，不同之处是它返回输出的最后一行，并且可选地用命令的完整输出和错误代码填充数组。
The exec() command is similar to shell_exec(), except it returns the last line of the output and, optionally, populates an array with the full output of the command, along with the error code.
可选的特性和行为应该可以被用户静态的（通过类似于#define的东西）或动态的（通过mallopt这样的控制命令）控制。
Optional features and behavior should be controllable by users either statically (via #define and the like) or dynamically (via control commands such as mallopt).
要想让RSS提要聚合器开始工作，必须使用下面的命令语法（注意此命令语法末的最后一个标记是一个可选的命令行参数）
To put the RSS feed aggregator to work, you have to use the following command syntax (note that the last token at the end of the command syntax below is an optional command-line argument)
这些抽象层让开发人员可选择是使用基于特性标记的声明语法，还是使用基于嵌套控件的命令模型来开发。
These abstraction layers give developers the option to use a declarative syntax based on attributes or an imperative model based on nested controls.
可选操作：为了验证所生成命令是否成功执行，您可以查看变更管理脚本编辑器的MessagesSection。
Optional: to validate successful execution of the generated commands, look in the Messages Section of the change management script editor.
访问存储库时要可选地使用静态SQL，请使用bind命令创建数据库包，如清单2所示。
To optionally use static SQL when accessing the repository, use the bind command to create the database packages, as shown in Listing 2.
命令执行还支持可选的超时(timeout)值。
list命令的可选参数意味着该命令可以列出具体文件或所有文件，这取决于调用命令的方式。
The optional parameters to the list command imply that the command can list specific files, or all the files, depending on how the command was invoked.
其他可选的安装方式包括，使用您最喜欢的包管理系统、或者只需下载IPython并键入以下命令。
Other options for installation include, using your favorite package management system, or just downloading IPython and typing.
你会看到几行可选择的命令行，最安全的方法是选择1并按下y会创建空白的密码。
You will see several commands that you can choose, the command is safest to create a password to be blank. Do this by pressing the number ’1 ‘, then press’ y’ to confirm
也可选择手动备份，运行以下命令。
You can also choose to back them up manually by issuing the following command.
一个可选的“命令通道”功能提供了第二个音频输出，每通道。
An optional "Command channel" function provides a second audio output per channel.
一个可选的“命令通道”功能提供了第二个音频输出，每通道。
An optional "Command channel" function provides a second audio output per channel.
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