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SEARCH KEYWORD -- char pointer

  Smuggling data in pointers

While reading up on The ABA Problem I came across a fantastic hack.  The ABA problem, in a nutshell, results from the inability to atomically access both a pointer and a "marked" bit at the same time (read the wikipedia page).  One fun, but very hackish solution is to "smuggle" data in a pointer.  Example:#include "stdio.h"void * smuggle(void * ptr, int value){  return (void *)( (long long)ptr | (value & 3) );}int recoverData(void * ptr){  return (long long)ptr &...

   C,Pointer,Bit,Data,Atomic,Smuggle     2011-11-14 08:15:59

  Read white space with scanf()

Usually, when we want to enter string with white spaces in C, we need to call gets() or fgets(0 method. We usually will not use scanf(0 or fscanf() because they cannot accept white spaces when scan user inputs.   But when we specify the format in scanf() function, we may read strings with white space. the code section below illustrate this: #include <stdio.h>   int main(int argc,char **argv){        char name[30];      fprintf(stdout,"Please en...

   C,scanf,white space, string format     2011-09-26 11:45:43

  Understanding PHP's internal function definitions

Welcome to the second part of the “PHP’s Source Code For PHP Developers” series. In the previous part ircmaxell explained where you can find the PHP source code and how it is basically structured and also gave a small introduction to C (as that’s the language PHP is written in). If you missed that post, you probably should read it before starting with this one. What we’ll cover in this article is locating the definitions of internal functions in t...

   PHP,internal function,definition,rationale     2012-03-16 10:46:26

  Data type in MySQL

For both small free database space and large e-commerce websites, reasonable database table structure design is essential. To achieve this, it requires us to have a full understanding of commonly used data types in database system. Below we share some knowledge about data types in MySQL.1. Numeric typesThe numeric types can be classified as : integer, float and decimal type.The so-called "decimal" refers DECIMAL and NUMERIC, they are of the same type. Strictly speaking it is not a numeric type, ...

   MySQL, Data type,VARCHAR     2013-01-01 10:56:06

  Be careful about nil check on interface in GoLang

nil check is frequently seen in GoLang code especially for error check since GoLang's special error handling convention. In most cases, nil check is straight forward, but in interface case, it's a bit different and special care needs to be taken. Take a look at below code snippet and guess what the output will be. package main import ( "bytes" "fmt" "io" ) func check(w io.Writer) { if w != nil { fmt.Println("w is not nil") } fmt.Printf("w is %+v\n", w) } func main() { var b *bytes.B...

   INTERFACE,GOLANG,NIL CHECK,NIL TYPE,NIL VALUE     2019-04-06 07:47:07

  Two things I don’t like about Hacker News

Hacker News is a very famous IT information hub. We can find many useful links about the latest IT news and fantastic technology demos. But there are two things I don’t like about Hacker News. Maybe some of you also have the same feelings.1.  About the more link. Every time we click the more link to go to next page, there will be a unique key generated to produce the new page. It is a good security mechanism. Also it may increase pages views as we need to read page by page bu...

   Hacker news,More link,Submission,Security     2012-02-28 11:55:37

  Understanding Slice Behavior in Go

In Go, understanding how slices behave when passed to functions is crucial for writing efficient and bug-free code. This behavior is often a source of confusion for many developers, especially those new to the language. In this article, we'll explore the difference between passing slices by value and by reference, and how it impacts the modification of slices within functions. Introduction In Go, slices are a fundamental data structure used to work with sequences of elements. They are essentiall...

   PASS BY REFERENCE,ARRAY,SLICE,PASS BY VALUE     2024-03-10 06:43:51

  Do you really understand C? 21st International Obfuscated C Code Contest winning entries

The 21st International Obfuscated C Code Contest(IOCCC) officially launched the winning source code. IOCCC requires contestants to write the most creative and the most obfuscated C codes with the size limited to 4kb and less Work of each participant is impressive. The winners, including one French, one Korean, five Americans, one Belgian, one Israeli, one British, four Japanese and one Chinese. Here we list some codes: Best short program Seonghoon Kang  from Korea- Decodes spelled out ...

   C,Obsfucation contest     2012-10-25 12:26:55

  The hidden risk of passing slice as function parameter

In Go's source code or other open source libraries, there are lots of cases where a slice pointer is passed to function instead of slice itself. This brings up a doubt why not passing slice directly as its internal is backed by an array pointer to point to underlying data? For example, in log package, the formatHeader function takes a parameter buf as type *[]byte instead of []byte. func (l *Logger) formatHeader(buf *[]byte, t time.Time, file string, line int) {} Let's understand the r...

   GOLANG,SLICE,SLICE POINTER     2020-12-13 06:11:14

  Why using + to concatenate string in Java loop is not a good option

String concatenation is a common operation in Java programming. It is to concatenate multiple strings into a single string. Java provides a String class which is an immutable class which means the object cannot be mutated once instantiated. Once a String object is instantiated, its properties cannot be changed anymore, so when concatenating strings, it's actually create a new String instance to store the concatenated string values. For example, below is a simple string concatenation example. Str...

   JAVA,STRING,JAVA 8     2019-01-18 22:07:12

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