on mac, you probably using mongodb for development purpose. If yes, then you can ignore this.

**Scenario**: Consider the following is the part of code from a node web app.

    app.get(&#39;/users/:id?&#39;, function(req, res, next){
        var id = req.params.id;
        if (id) {
            // do something
        } else {
            next(); //or return next();
        }
    });

**Issue**: I am checking which one to go with just `next()` or `return next()`. Above sample code works exactly the same for both &amp; did not show any difference in execution. 

**Question**: Can some one put light on this, when to use `next()` and when to use `return next()` and some important difference?

When to use next() and return next() in Node.js

I&#39;m developing an application using Spring. I need to use the `@Service` annotation. I have `ServiceI` and `ServiceImpl` such that `ServiceImpl implements ServiceI`. I&#39;m confused here as to where should I keep the `@Service` annotation.

Should I annotate the interface or the implementation with `@Service`? What are the differences between these two approaches?

Where should @Service annotation be kept? Interface or Implementation?

I&#39;ve been using mongo on my mac os x 10.8 and suddenly yesterday at my logs appeared this warning (and when starting shell it&#39;s present too) - 

&gt; WARNING: soft rlimits too low. Number of files is 256, should be at least 1000

Who could explain, what does it mean? And should I increase number of **rlimits** somehow?

mongod, mac os x - rlimits warning

I've been using mongo on my mac os x 10.8 and suddenly yesterday at my logs appeared this warning (and when starting shell it's present too) -
> WARNING: soft rlimits too low. Number of files is 256, should be at least 1000
Who could explain, what does it mean? And should I increase number of rlimits somehow?

Despite having hidden folders turned on, sublime text cannot see invisible folders in the sidebar such as a git repository. How can I fix this?

Mac OSX 10.7.5


Sublime Text 2.0.1

Show hidden folders in sublime text? (Mac osx)

Here is the project structure:

    /
      app.js
      package.json
      /node_modules
      /app
        config.json
        /frontend
          assets and html tpls
        /modules
          couch.js
          raeume.js
          users.js

I require config.json, raeume.js and users.js from app.js and it all works fine.

    var config   = require(&#39;./app/config&#39;);
    var raeume   = require(&#39;./app/modules/raeume&#39;);
    var users    = require(&#39;./app/modules/users&#39;);

Then I require config.json and couch.js from user.js the same way and it won&#39;t find anything.

    var couch     = require(&#39;./app/modules/couch&#39;);
    var config    = require(&#39;./app/config&#39;);

I guess it should find it. After some research I saw a diverse landscape of problems inclusive how node is compiled. Thus included: I work on osx 10.8 with node v0.10.7.

node.js require cannot find custom module

It looks like the new version of OSX no longer supports `grep -P` and as such has made some of my scripts stop working.

    var1=`grep -o -P &#39;(?&lt;=&lt;st:italic&gt;).*(?=&lt;/italic&gt;)&#39; file.txt`

I need to capture the grep to a variable and I need to use the zero width assertions, as well as `\K`
 
    var2=`grep -P -o &#39;(property:)\K.*\d+(?=end)&#39; file.txt`

Any alternatives would be greatly appreciated.

grep -P no longer works. How can I rewrite my searches?

It works ok as a single tool:

    curl &quot;someURL&quot;
    curl -o - &quot;someURL&quot;

but it doesn&#39;t work in a pipeline:

    curl &quot;someURL&quot; | tr -d &#39;\n&#39;
    curl -o - &quot;someURL&quot; | tr -d &#39;\n&#39;

it returns:

    (23) Failed writing body

What is the problem with piping the cURL output? How to buffer the whole cURL output and then handle it?

Why does cURL return error &quot;(23) Failed writing body&quot;?

I know nothing about Sed but need this command (which works fine on Ubuntu) to work on a Mac OSX:

    sed -i &quot;/ $domain .*#drupalpro/d&quot; /etc/hosts

I&#39;m getting:

    sed: 1: &quot;/etc/hosts&quot;: extra characters at the end of h command

sed command with -i option (in-place editing) works fine on Ubuntu but not Mac

Everybody.
In mongo group query, the result shows only the key(s) in arguments. How to keep the first document in each group like mysql query group.
for example:


    -------------------------------------------------------------------------
    |  name  | age  |  sex  | province |   city   |   area   |   address     |
    -------------------------------------------------------------------------
    | ddl1st | 22   | 纯爷们 |  BeiJing |  BeiJing | ChaoYang | QingNianLu    |
    | ddl1st | 24   | 纯爷们 |  BeiJing |  BeiJing | XuHui    | ZhaoJiaBangLu |
    |  24k   | 220  | ...   |  ....    |  ...     | ...      | ...           |
    -------------------------------------------------------------------------



    db.users.group({key: { name: 1},reduce: function ( curr, result ) { result.count ++ },initial: {count : 0 } })

result:

    [
	{
		&quot;name&quot; : &quot;ddl1st&quot;,
		&quot;count&quot; : 1
	},
	{
		&quot;name&quot; : &quot;24k&quot;,
		&quot;count&quot; : 1
	}
    ]

How to get the following:


    [
       {
       &quot;name&quot; : &quot;ddl1st&quot;,
       &quot;age&quot; : 22,
       &quot;sex&quot; : &quot;纯爷们&quot;,
       &quot;province&quot; : &quot;BeiJing&quot;,
       &quot;city&quot; : &quot;BeiJing&quot;,
       &quot;area&quot; : &quot;ChaoYang&quot;,
       &quot;address&quot; : &quot;QingNianLu&quot;,
       &quot;count&quot; : 1
	   },
	   {
       &quot;name&quot; : &quot;24k&quot;,
       &quot;age&quot; : 220,
       &quot;sex&quot; : &quot;...&quot;,
       &quot;province&quot; : &quot;...&quot;,
       &quot;city&quot; : &quot;...&quot;,
       &quot;area&quot; : &quot;...&quot;,
       &quot;address&quot; : &quot;...&quot;,
       &quot;count&quot; : 1
	}
    ]


mongo group query how to keep fields

This is my appointment collection:


        
    { _id: ObjectId(&quot;518ee0bc9be1909012000002&quot;), date: ISODate(&quot;2013-05-13T22:00:00Z&quot;), patient:ObjectId(&quot;518ee0bc9be1909012000002&quot;) }
    
    { _id: ObjectId(&quot;518ee0bc9be1909012000002&quot;), date: ISODate(&quot;2013-05-13T22:00:00Z&quot;), patient:ObjectId(&quot;518ee0bc9be1909012000002&quot;) }
    
    { _id: ObjectId(&quot;518ee0bc9be1909012000002&quot;), date: ISODate(&quot;2013-05-13T22:00:00Z&quot;), patient:ObjectId(&quot;518ee0bc9be1909012000002&quot;) }

I used aggregate to get the following result
        
    {date: ISODate(&quot;2013-05-13T22:00:00Z&quot;),
    patients:[ObjectId(&quot;518ee0bc9be1909012000002&quot;),ObjectId(&quot;518ee0bc9be1909012000002&quot;),ObjectId(&quot;518ee0bc9be1909012000002&quot;)] }

like this:


    Appointments.aggregate([
    {$group: {_id: &#39;$date&#39;, patients: {$push: &#39;$patient&#39;}}},
    {$project: {date: &#39;$_id&#39;, patients: 1, _id: 0}}
    ], ...)


How can I populate the patient document
I trued this but it doesn&#39;t work ... `Appointments.find({}).populate(&quot;patient&quot;).aggregate`....

In other words, can i use populate and aggregate at the same statement

any help please

how to use populate and aggregate in same statement?

Does **Mongoose v3.6+** support batch inserts now? I&#39;ve searched for a few minutes but anything matching this query is a couple of years old and the answer was an unequivocal no.

Edit:

For future reference, the answer is to use `Model.create()`. `create()` accepts an array as its first argument, so you can pass your documents to be inserted as an array.

See [Model.create() documentation][1]


  [1]: http://mongoosejs.com/docs/api.html#model_Model.create

Mongoose (mongodb) batch insert?

How can I make a backup of my meteor mongo database?

If I run:

    meteor mongo

the mongodump command does not work inside the meteor mongoshell

meteor: how can I backup my mongo database

I saw the following code in [this commit][2] for [MongoDB&#39;s Java Connection driver][3], and it appears at first to be a joke of some sort. What does the following code do?

    if (!((_ok) ? true : (Math.random() &gt; 0.1))) {
        return res;
    }

(EDIT: the code [has been updated since][1] posting this question)

  [1]: https://github.com/mongodb/mongo-java-driver/commit/8e02cd006d79acd1d0ae6604c2ee7537b250c044#diff-08d4a794472cb22d6bf2c4bb0615aa49L212
  [2]: https://github.com/mongodb/mongo-java-driver/blob/1d2e6faa80aeb5287a26d0348f18f4b51d566759/src/main/com/mongodb/ConnectionStatus.java#L213
  [3]: https://github.com/mongodb/mongo-java-driver


Why does the MongoDB Java driver use a random number generator in a conditional?

If you specify axis limits in ggplot the outlying points are removed.  This is fine for points, but you might want to plot lines that intersect with the specified range, but ggplot&#39;s `range` or `xlim/ylim` methods removes these.  Is there another way to specify the plot axis range without removing outlying data?

e.g.

    require(ggplot2)
    d = data.frame(x=c(1,4,7,2,9,7), y=c(2,5,4,10,5,3), grp=c(&#39;a&#39;,&#39;a&#39;,&#39;b&#39;,&#39;b&#39;,&#39;c&#39;,&#39;c&#39;))
    ggplot(d, aes(x, y, group=grp)) + geom_line()
    ggplot(d, aes(x, y, group=grp)) + geom_line() + scale_y_continuous(limits=c(0,7))
    ggplot(d, aes(x, y, group=grp)) + geom_line() + ylim(0,7)

Content Type	Original Author	Original Content on Stackoverflow
Question	Kosmetika	View Question on Stackoverflow
Solution 1 - Macos	Aniruddha	View Answer on Stackoverflow

mongod, mac os x - rlimits warning

Macos Problem Overview

Macos Solutions

Solution 1 - Macos

Where should @Service annotation be kept? Interface or Implementation?

When to use next() and return next() in Node.js

Attributions