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How to debug Ruby scripts [closed]
...ject (e.g. lines starting with app/... if you are using Rails). 99% of the time the problem is with your own code.
To illustrate why interpreting in this order is important...
E.g. a Ruby error message that confuses many beginners:
You execute code that at some point executes as such:
@foo = F...
After Installing Java JDK 7 For Mac OS X - mvn -version still shows java version 1.6.0_31
...lling Maven on a 64-bit Mac running Mac OSX 'Mavericks' save yourself some time and some hair pulling trying to get Maven installed. I was trying to follow this (which failed because the location of the java_home has changed on Mavericks:
http://maven.apache.org/download.cgi
I was pulling my hair ...
Optimise PostgreSQL for fast testing
...erformance improvements are always coming, so you're probably wasting your time if you're tuning an old version. For example, PostgreSQL 9.2 significantly improves the speed of TRUNCATE and of course adds index-only scans. Even minor releases should always be followed; see the version policy.
Don't...
How to grep Git commit diffs or contents for a certain word?
In a Git code repository I want to list all commits that contain a certain word. I tried this
8 Answers
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Are parameters in strings.xml possible? [duplicate]
In my Android app I'am going to implement my strings with internationalization. I have a problem with the grammar and the way sentences build in different languages.
...
How to calculate moving average without keeping the count and data-total?
...t @Muis describes is an exponentially weighted moving averge, which is sometimes appropriate but is not precisely what the OP requested. As an example, consider the behaviour you expect when most of the points are in the range 2 to 4 but one value is upwards of a million. An EWMA (here) will hold ...
When should null values of Boolean be used?
...
Use boolean rather than Boolean every time you can. This will avoid many NullPointerExceptions and make your code more robust.
Boolean is useful, for example
to store booleans in a collection (List, Map, etc.)
to represent a nullable boolean (coming from a nul...
pip installing in global site-packages instead of virtualenv
...a how it started. My suspicion is running multiple virtualenvs at the same time).
If none of this works, a temporary solution may be to, as Joe Holloway said,
Just run the virtualenv's pip with its full path (i.e. don't rely on searching the executable path) and you don't even need to activate ...
How to get whole and decimal part of a number?
...
The floor() method doesn't work for negative numbers. This works every time:
$num = 5.7;
$whole = (int) $num; // 5
$frac = $num - $whole; // .7
...also works for negatives (same code, different number):
$num = -5.7;
$whole = (int) $num; // -5
$frac = $num - $whole; // -.7
...
TCP 的那些事儿（下） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...所中阅读。
TCP的RTT算法
从前面的TCP重传机制我们知道Timeout的设置对于重传非常重要。
设长了，重发就慢，丢了老半天才重发，没有效率，性能差；
设短了，会导致可能并没有丢就重发。于是重发的就快，会增加网络拥塞...