replServer.defineCommand(keyword, cmd)
keyword
<string> 命令关键字(不带前导.
字符)。cmd
<Object> | <Function> 当处理命令时调用的函数。
replServer.defineCommand()
方法用于向 REPL 实例添加新的以 .
为前缀的命令。
此类命令是通过键入 .
后跟 keyword
来调用的。
cmd
是具有以下属性的 Function
或 Object
:
help
<string> 当输入.help
时显示的帮助文本(可选)。action
<Function> 要执行的函数,可选择接受单个字符串参数。
以下示例显示了添加到 REPL 实例的两个新命令:
const repl = require('repl');
const replServer = repl.start({ prompt: '> ' });
replServer.defineCommand('sayhello', {
help: 'Say hello',
action(name) {
this.clearBufferedCommand();
console.log(`Hello, ${name}!`);
this.displayPrompt();
}
});
replServer.defineCommand('saybye', function saybye() {
console.log('Goodbye!');
this.close();
});
然后可以在 REPL 实例中使用新命令:
> .sayhello Node.js User
Hello, Node.js User!
> .saybye
Goodbye!
keyword
<string> The command keyword (without a leading.
character).cmd
<Object> | <Function> The function to invoke when the command is processed.
The replServer.defineCommand()
method is used to add new .
-prefixed commands
to the REPL instance. Such commands are invoked by typing a .
followed by the
keyword
. The cmd
is either a Function
or an Object
with the following
properties:
help
<string> Help text to be displayed when.help
is entered (Optional).action
<Function> The function to execute, optionally accepting a single string argument.
The following example shows two new commands added to the REPL instance:
const repl = require('repl');
const replServer = repl.start({ prompt: '> ' });
replServer.defineCommand('sayhello', {
help: 'Say hello',
action(name) {
this.clearBufferedCommand();
console.log(`Hello, ${name}!`);
this.displayPrompt();
}
});
replServer.defineCommand('saybye', function saybye() {
console.log('Goodbye!');
this.close();
});
The new commands can then be used from within the REPL instance:
> .sayhello Node.js User
Hello, Node.js User!
> .saybye
Goodbye!