1.Configure the mongo Shell-官方文档摘录

Customize the Prompt 自定义提示

You may modify the content of the promptby setting the variable

prompt

in the

mongo

shell. The

prompt

variable can hold strings as well as JavaScript code. If

prompt

holds a function that returns a string,

mongo

can display dynamic information in each prompt.

You can add the logic for the promptin the .mongorc.js file to set the prompteach time you start up the

mongo

shell.

大概的意思:你可以通过修改mongorc.js这个文件来让你的终端提示符变得不太一样

注意：

# vim /root/.mongorc.js

如果使用yum 装的，这个文件在/root/目录下

Customize Prompt to Display Number of Operations

For example,to create a

mongo

shell promptwith the number of operations issued in the current session, define the following variables in the

mongo

shell:

cmdCount = 1;
prompt= function() {
return (cmdCount++) + "> ";
}

The promptwould then resemble the following:

1>
2>
3>

Customize Prompt to Display Database and Hostname

To create a

mongo

shell promptin the form of

<database>@<hostname>$

, define the following variables:

host = db.serverStatus().host;

prompt= function() {
return db+"@"+host+"$ ";
}

The promptwould then resemble the following:

test@myHost1$

Customize Prompt to Display Up Time and Document Count

To create a

mongo

shell promptthat contains the system up time and the number of documents in the current database, define the following

prompt

variable in the

mongo

shell:

prompt= function() {
return "Uptime:"+db.serverStatus().uptime+" Documents:"+db.stats().objects+" > ";
}

The promptwould then resemble the following:

Uptime:5897 Documents:6 >

Use an External Editor in the

mongo

Shell

You can use your own editor in the

mongo

shell by setting the

EDITOR

environment variable before starting the

mongo

shell.

export EDITOR=vim
mongo

Once in the

mongo

shell, you can edit with the specified editor by typing

edit <variable>

or

edit<function>

, as in the following example:

Define a function

myFunction

:

function myFunction () { }

Edit the function using your editor:

edit myFunction

The command should open the

vim

edit session. When finished with the edits, save and exit

vim

edit session.

In the

mongo

shell, type

myFunction

to see the function definition:

myFunction

The result should be the changes from your saved edit:

function myFunction() {
print("This was edited");
}

NOTE

As

mongo

shell interprets code edited in an external editor, it may modify code in functions, depending on the JavaScript compiler. For

mongo

may convert

1+1

to

2

or remove comments. The actual changes affect only the appearance of the code and will vary based on the version of JavaScript used but will not affect the semantics of the code.

以上大概的意思是:通过集中方式来设置显示的方式，需要注意的是mong shell的解释器会依赖于js的版本，即使你使用了编辑器，还是依靠于js的解释器。它只会影响代码的展现而不会影响代码本身的意思

Change the

mongo

Shell Batch Size

The

db.collection.find()

method is the JavaScript method to retrieve documents from a collection. The

db.collection.find()

method returns a cursor to the results; however, in the

mongo

shell, if the returned cursor is not assigned to a variable using the

var

keyword, then the cursor is automatically iterated up to 20 times to print up to the first 20 documents that match the query. The

mongo

shell will prompt

Typeit

to iterate another 20 times.

You can set the

DBQuery.shellBatchSize

attribute to change the number of documents from the default value of

20

, as in the following example which sets it to

10

:

DBQuery.shellBatchSize = 10;
大概的意思是:因为在mongo shell中，默认只会将前面20条的结果显示出来，修改默认的显示迭代次数，可以使用

DBQuery.shellBatchSize来设置