Blog

Function static variable的后续研究和例程

函数静态变量引发的奇怪crash

最新的kernel和软件版本不一定适合

a check list for a software project

learned from previous projects how to plan a product’s live-update feature at beginning

中年男人的掩耳盗铃

add .local doman suffix

mdadm soft raid fails after kernel upgrade

In shell command, compare version string in a better way

summary

In modern opengl (core profile), there are a lot of tutorials on how to draw a circle using fragment shader,but most of lack of source code and only show how to draw at (0,0).This code piece draw circle at given center point with specified radius.pyopengl implementation is at github: https://github.com/stonewell/code-snippets/tree/master/opengl%5Fcircle

Modern opengl (core profile), the line width is limited by system.In order to draw a free width line smooth, we draw multiple triangles to construct a thick line.pyopengl implmentation is at github:https://github.com/stonewell/code-snippets/tree/master/opengl%5Fthick%5Fline

calculate div and mod result between 2 uint64_t values without directly using / and % operator

SWIG is a software development tool that connects programs written in C and C++ with a variety of high-level programming languages. SWIG is used with different types of target languages including common scripting languages such as Javascript, Perl, PHP, Python, Tcl and Ruby. The list of supported languages also includes non-scripting languages such as C#, Common Lisp (CLISP, Allegro CL, CFFI, UFFI), D, Go language, Java including Android, Lua, Modula-3, OCAML, Octave, Scilab and R.

Rendering 2d text with opengl, either using bitmap font or freetype library

http://www.darkreading.com/ http://securityweekly.com/ http://www.technewsworld.com/perl/section/tech-security/ http://ddosattackprotection.org/blog/cyber-security-blogs/ https://heimdalsecurity.com/blog/best-internet-security-blogs/ http://www.rasmussen.edu/degrees/technology/blog/top-cyber-security-blogs/ http://www.veracode.com/blog/2012/02/top-20-security-blogs http://www.marblesecurity.com/2014/01/22/top-10-security-blogs/

To Build your own render farmRender Manager: http://cgru.info/homeA blog page talking about how to built your own Render Farm: http://arstechnica.com/information-technology/2014/05/how-to-network-lots-of-dumb-computing-muscle-in-a-fast-efficient-render-farm/1/a maya script for v-ray http://www.creativecrash.com/maya/script/v-ray-tuner-for-maya

关于唐诗的那些猛人猛事

Original URL:How (and Why) to Assign the .local Domain to Your Raspberry Pi

It is very interesting technology. Basically the device to be configured put the wifi device in “monitoring” mode,and the app will send udp wifi packet with different length, which different length indicate different “character”.http://depletionregion.blogspot.ch/2013/10/cc3000-smart-config-transmitting-ssid.htmlhttp://electronics.stackexchange.com/questions/61704/how-does-ti-cc3000-wifi-smart-config-work

Original Post URL:https://www.bestvpn.com/blog/11385/protect-cloud-storage-files-encfs/

Original Post URL:https://www.virusbtn.com/virusbulletin/archive/2015/03/vb201503-dylib-hijacking

summary

http://rancher.com/introducing-ranchervm-package-and-run-virtual-machines-as-docker-containers/

Original Post URL:https://panthema.net/2008/0901-stacktrace-demangled/ // stacktrace.h (c) 2008, Timo Bingmann from http://idlebox.net/ // published under the WTFPL v2.0 #ifndef _STACKTRACE_H_ #define _STACKTRACE_H_ #include <stdio.h>#include <stdlib.h>#include <execinfo.h>#include <cxxabi.h> /** Print a demangled stack backtrace of the caller function to FILE* out. */ static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames = 63) { fprintf(out, "stack trace:\n"); // storage array for stack trace address data void* addrlist[max_frames+1]; // retrieve current stack addresses int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*)); if (addrlen == 0) { fprintf(out, " <empty, possibly corrupt>\n"); return; } // resolve addresses into strings containing "filename(function+address)", // this array must be free()-ed char** symbollist = backtrace_symbols(addrlist, addrlen); // allocate string which will be filled with the demangled function name size_t funcnamesize = 256; char* funcname = (char*)malloc(funcnamesize); // iterate over the returned symbol lines.

The iOS8 or newer platform now supports dynamic library, here is a link details about the dynamic linking. http://ddeville.me/2014/04/dynamic-linking/

Original Post URL:http://www.impetus.us/~rjmooney/projects/misc/clientcertauth.html

When create executable or dynamic library, sometimes they need to depends on third-party shared library, so how system find the third-party shared library and how can you make sure the system find the right version of library instead of some library in same name? Solution could be pack the correct third-party library with your executable or library, but how to let system find the packed library? most platform has search directory list to find dependent libraries, even you put the third-party library in the same directory, the system still could find wrong one.

jar.mn document http://dxr.mozilla.org/mozilla-central/source/build/docs/jar-manifests.rst https://developer.mozilla.org/en-US/docs/HowMozilla'sbuildsystemworks https://developer.mozilla.org/en-US/docs/UsingDependentLibrariesInExtension%5FComponents https://developer.mozilla.org/en-US/docs/Bundlingmultiplebinary%5Fcomponents https://code.google.com/p/gears/source/browse/trunk/gears/base/firefox/static%5Ffiles/components/stub.js https://developer.mozilla.org/en-US/Add-ons/CreatingCustomFirefoxExtensionswiththeMozillaBuildSystem https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Guide/Cross-threadcallsusing%5Frunnables

dynamic_cast requires RTTI flag when do compiling, the RTTI will increase object size. and RTTI only generate for polymorphic classes. class A { public: std::string m_Data; } although A class is not polymorphic, but the m_Data is a instance of polymorphic class, the sizeof(A) will change when compile with/without RTTI. programmer should be very carefully when link with third-party library, it is more difficult to find out the crash compare to pack problem.

To create auto increment build number without third-party component, script or other code, just pure ant tasks. please refer to http://stackoverflow.com/questions/1431315/build-numbers-major-minor-revision

summary

The error message looks like Error occurred during the SSL handshake: invalid SSL session It may caused by JVM needs the JCE, download JCE from Oracle and follow instructions in README http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html

When using PowerMock https://code.google.com/p/powermock/ to do unit test, some times jvm may report bytecode version mismatch and refuse to run, it caused by PowerMock will dynamic change the bytecode. Add -noverify option to fix the problem

今天写代码的时候突然不能肯定const char * d; d++; 是不是对的了，就重温了一下经典的c++定义结论： char * const p 定义一个指向字符的指针常数，即const指针 const char * p 定义一个指向字符常数的指针 char const*p 等同于const char* p 普通的指针d，进行d++肯定没问题了http://blog.163.com/pei%5Fhua100/blog/static/805697592009550281616/

First we need to create a certificate (self-signed) for our ssh key:openssl req -new -x509 -key ~/.ssh/id_rsa -out ssh-cert.pem We can now import it in GnuPG openssl pkcs12 -export -in ssh-certs.pem -inkey ~/.ssh/id_rsa -out ssh-key.p12 gpgsm --import ssh-key.p12 Notice you cannot import/export DSA ssh keys to/from GnuPG The more key conversions, please refer tohttp://www.sysmic.org/dotclear/index.php?post/2010/03/24/Convert-keys-betweens-GnuPG,-OpenSsh-and-OpenSSL

Decode a hex string by using look up table char m_table['f' + 1]['f' + 1] = {0}; void initDecodeTable() { const char * hexValue = "0123456789abcdefABCDEF"; int len = strlen(hexValue); for(int i=0;i < len;i++) { for(int j=0;j int v; char tmp[2] = { tolower(hexValue[i]), tolower(hexValue[j]) }; sscanf(tmp, "%x", &v); m_table[hexValue[i]][hexValue[j]] = (v & 0xFF); } } } void decodeHex(const char * pIn, int inLen, char * pOut, int & outLen) { outLen = inLen / 2; for(int i=0; i < outLen;i++) { pOut[i] = m_table[pIn[i * 2]][pIn[i * 2 + 1]]; } if (inLen % 2 !

在unix，maxosx或者linux下工作的时候，经常需要长时间运行一个程序，通常会把程序放到后台，然后通过日志来监控。如果使用screen的话，可以让程序保持前台运行，又能通过detach放到后台。如果在公司机器上用screen运行一个程序，然后detach，回家后通过ssh连接公司机器，用screen restore就可以继续观察程序运行了。可是如果一开始没有用screen运行，直接放置到后台怎么办呢。reptyr就派上用场了，以下是reptyr的说明 reparent a orphan background process, means background a process in a terminal and bring it back to foreground to another terminal reptyr - A tool for "re-ptying" programs. ----------------------------------------- reptyr is a utility for taking an existing running program and attaching it to a new terminal. Started a long-running process over ssh, but have to leave and don't want to interrupt it? Just start a screen, use reptyr to grab it, and then kill the ssh session and head on home.

通过一些ssh的客户端，可以很方便的做ssh forward，也就是通过一台主机上ssh连接到另一台主机，那么命令行可不可以呢？只要在~/.ssh/config中加入如下指令即可host serverB.example.com serverB ProxyCommand ssh -W %h:%p gateway serverB是最终的目的主机，gateway是中间转发的主机，gateway上需要配置无密码登录。或者暴力一点ssh -t usergateway@gateway ssh user1@serverb