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  errGroup in GoLang explained

Today, let's talk about the usage and applicable scenarios of errGroup, which is often used. Why is it useful? Generally, when we use goroutine, we cannot return a value. If you want to pass out the result of the goroutine execution, you usually have to use the channel. The errGroup package is suitable if you want to know when the goroutine you opened encounters an error during execution and stop working, and I need to know the error value. errGroup usage The package needs to be downloaded and i...

   GOLANG,ERRGROUP,WAITHROUP,CONCURRENCY     2023-05-27 23:58:20

  Create temp file in Bash using mktemp and trap

When working on Linux Bash, sometimes there is need to create temporary file. A common way of creating temp file on Linux is creating some file in /tmp directory. However there is security risk when creating temp file in /tmp directory. This post will show how to securely create temp file in Linux Bash. When creating file in /tmp directory, there are some security risks. This directory can be accessed by any user on the system, any user can write data into this directory as well. The files creat...

   LINUX,MKTEMP,TRAP,TEMP FILE     2019-12-30 23:28:23

  Automatically post to Facebook from PHP script

Facebook is currently on of the most important publishing and traffic generating sources for many websites. Manually Cross publishing content on your own site and Facebook seems like a lot of extra work. This post guides you through the creation of a Facebook application that can automatically post messages and other types of content on your Facebook wall. Getting started Building a php script that automatically posts status updates on your wall requires the following steps: Download Faceboo...

   PHP,Facebook,API,Auto post,OAuth     2012-02-27 09:03:00

  Supercolliding a PHP array

Did you know that inserting 2^16 = 65536 specially crafted values into a normal PHP array can take 30 seconds? Normally this would take only 0.01 seconds. This is the code to reproduce it: <?php echo '<pre>'; $size = pow(2, 16); // 16 is just an example, could also be 15 or 17 $startTime = microtime(true); $array = array(); for ($key = 0, $maxKey = ($size - 1) * $size; $key <= $maxKey; $key += $size) { $array[$key] = 0; } $endTime = microtime(true); echo 'Inserting...

   PHP,Array,hashtable,Slow,Colliding     2011-12-29 09:02:01

  What do programmers like to say usually?

Coding is an very important part of programmer's daily work. But beyond coding, programmers need to do other work as well, they need to fix bugs reported by users, they need to write documents for their codes. Also, they often need to answer questions from customers, bosses and colleagues. What do they often say when they are facing different sort of questions? Today we share some. It's done. I just need to clean up a few things. This is hacky, but I'll fix it soon. This can never happen: It's ...

   Programmer,Execuse,Bug     2013-08-07 07:38:30

  Going Simple with JavaScript

I was making a change to a page that needed to pull from a remote API and make changes to various parts of the page. Sounds like the time to pull out jQuery and Ajax, doesn't it? Instead, I just used old fashioned JavaScript. Actually, I used new fashioned JavaScript. Browsers haven't stood still in the advent of libraries and frameworks. As a result, we can take advantage of those features when we need to bake in a little extra. Some JSONP The first step was to get the JSONP call execu...

   JavaScript,new version,new addition,JSONP,querySelectorAll     2012-03-06 05:22:59

  Fastjson just fixed a bug which might cause out of memory issue

Fastjson just fixed a bug which might cause service down a few days ago. This bug is caused by some mishandling of special character \x which is an escaped character to indicate hexdecimal number. The impact of this bug would be big if the attacker constructs a malicious data which would cause the service down.  The code which causes the issue is in com.alibaba.fastjson.parser.JSONLexerBase#scanString, when a JSON string is passed in, fastjson would parse the string character by c...

   FASTJSON,ALIBABA,BUG,NEWS     2019-09-07 06:03:49

  Why no max/min function for integer in GoLang

You may notice that there is no max/min function provided to compare the maximum/minimum of two or more integers if you are a GoLang developer with some experience . In other languages, these functions are provided as part of the core lib functions. Have you wondered why?  Indeed GoLang provides max/min function in math package, but they are used for comparing float64 data type. The signature of these two functions are math.Min(float64, float64) float64 math.Max(float64, float64) float...

   GOLANG,MAX,INT,INT64     2019-06-08 07:00:55

  Faster than C

Judging the performance of programming languages, usually C is called the leader, though Fortran is often faster. New programming languages commonly use C as their reference and they are really proud to be only so much slower than C. Few language designer try to beat C. What does it take for a language to be faster than C? Better Aliasing Information Aliasing describes the fact that two references might point to the same memory location. For example, consider the canonical memory copy: void...

   C,Performance,Speed,Fortran,Criteria     2012-03-25 09:12:23

  Vim anti-patterns

The benefits of getting to grips with Vim are immense in terms of editing speed and maintaining your “flow” when you’re on a roll, whether writing code, poetry, or prose, but because the learning curve is so steep for a text editor, it’s very easy to retain habits from your time learning the editor that stick with you well into mastery. Because Vim makes you so fast and fluent, it’s especially hard to root these out because you might not even notice them...

   Vim,Anti-pattern,macro,syntax     2012-02-08 10:06:15

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