This section will discuss all the things around UNIX and Linux machine/system.
Sometimes it is very annoying that the compiler always tells me there is a lot of warning in third-party headers. For example, boost headers.
After google awhile and found a solution to that in Stack-flow.
Just use #pragma to wrap the third-party and it’s done!
For example:
#pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wconversion" #include <boost/thread.hpp> #pragma GCC diagnostic pop |
This specification is referred to RFC822 which is used in RSS feed standard
date-time = [ day "," ] date time ; dd mm yy
; hh:mm:ss zzz
day = "Mon" / "Tue" / "Wed" / "Thu"
/ "Fri" / "Sat" / "Sun"
date = 1*2DIGIT month 2DIGIT ; day month year
; e.g. 20 Jun 82
month = "Jan" / "Feb" / "Mar" / "Apr"
/ "May" / "Jun" / "Jul" / "Aug"
/ "Sep" / "Oct" / "Nov" / "Dec"
time = hour zone ; ANSI and Military
hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
; 00:00:00 - 23:59:59
zone = "UT" / "GMT" ; Universal Time
; North American : UT
/ "EST" / "EDT" ; Eastern: - 5/ - 4
/ "CST" / "CDT" ; Central: - 6/ - 5
/ "MST" / "MDT" ; Mountain: - 7/ - 6
/ "PST" / "PDT" ; Pacific: - 8/ - 7
/ 1ALPHA ; Military: Z = UT;
; A:-1; (J not used)
; M:-12; N:+1; Y:+12
/ ( ("+" / "-") 4DIGIT ) ; Local differential
; hours+min. (HHMM)
First, set up a share folder/directory using the wizard of VirtualBox.
Assuming you have create a shared folder in the VirtualBox and its name is “to-be-shared“.
Then in the Linux client (e.g. Ubuntu), open a new terminal. Make a new directory and mount it using following commands
mkdir share sudo mount -t vboxsf to-be-shared share |
Now it works.
To unmount it just do:
sudo umount share rmdir share |
Then using wizard in the VirtualBox to umount the share folder in the system (you may do this when the client machine is powered off).
To take a screenshot with DOSBox on Mac is pretty easy on Mac.
1. Run your game on the DOSBox
2. Press control+F5
3. Go ~/Library/Preferences/capture/ and see the screenshot files.
In linux like ubuntu, we can simply type
sudo apt-get install [package-name]
to installs packages.
But in Mac OS X… there is no apt-get 🙁
Most of time I do download the source code and compile by myself because I am a geek 🙂
However, sometimes I have no time to debug the errors generated by the compiler and the problem of software dependency…
So guess what? Macports! If you are worried to install packages, macports is your friend. It does the same thing as apt-get and more powerful.
For example, I want to install mscgen, just type
sudo port install mscgen
and…that’s it. Macports will check the dependency and install all related packages including mscgen for you.
Here is the official site: http://www.macports.org/
Refer to http://en.wikipedia.org/wiki/Unix_domain_socket (For personal research)
A Unix domain socket or IPC socket (inter-process communication socket) is a data communications endpoint for exchanging data between processes executing within the same host operating system. While similar in functionality to named pipes, Unix domain sockets may be created as byte streams or as datagram sequences, while pipes are byte streams only. Processes using Unix domain sockets do not need to share a common ancestry. The programmer’s application interface (API) for Unix domain sockets is similar to that of an Internet socket, but does not use an underlying network protocol for communication. The Unix domain socket facility is a standard component of POSIX operating systems.
Unix domain sockets use the file system as address name space. They are referenced by processes as inodes in the file system. This allows two processes to open the same socket in order to communicate. However, communication occurs entirely within the operating system kernel.
In addition to sending data, processes may send file descriptors across a Unix domain socket connection using the sendmsg() and recvmsg() system calls.
Extra: unix domain sockets guide
I hate people using P2P downloaders to eat up the whole network access.
As I have the root access of the router (easy to hack), I add some rules to limit it.
iptables -I FORWARD -p tcp --syn -m connlimit --connlimit-above 30 -j DROP iptables -I FORWARD -p! tcp -m connlimit --connlimit-above 30 -j DROP
First line is to limit tcp connections to 30 per ip.
Second line is to limit non-tcp connections to 30 per ip.
Here is Chinese version:
限制连接数以防止P2P下载器例如迅雷、电驴、BT及P2P播放器例如PPS、PPLive、风行等。
以下为在路由器上执行的代码（通过telnet连接）
iptables -I FORWARD -p tcp --syn -m connlimit --connlimit-above 30 -j DROP iptables -I FORWARD -p! tcp -m connlimit --connlimit-above 30 -j DROP
第一行为限制tcp连接数到30个每ip。
第二行为限制非tcp连接数到30个每ip。
I am doing Java this session and have done my assignment 4 for socket practices.
The assignment contains 2 parts: Client and server.
I can’t modify the assignment to have proper log details (e.g. add time to logs) because it will lose marks 🙁
So, I did a bash script named “run”.
#!/bin/bash # Author name: Need-Being # Modification date: 14/10/2011 trap "" SIGHUP cd Server java JavaQuizServer 2>&1 | while read LINE do echo "`date '+[20%y/%m/%d-%T]'`[java] $LINE" >> ../JavaQuiz.log done |
“java JavaQuizServer” is the line to execute the program. I add the time before whatever it output and send it to “JavaQuiz.log”
‘trap “” SIGHUP’ is used for ignore signal SIGUP that it can be alive after closing it parent process i.e. ssh.
Continue reading A bash script to monitor and log a CLI application
If you trying to compile source code, having some STL used, with CC in SunOS. You may fail.
For example:
If you use std::list::sort() in, you will get following error like this one:
Error: Could not find a match for std::list::sort(bool(int,int))
This happens because CC is using the old libCstd .
Continue reading Some functionalities in STL is missing using CC
When using try-catch blocks in C++, it is not a good to throw exceptions in destructor. Briefly, it may cause SIGABORT at runtime since the exception thrown in destructor may not be caught.
In MAC OS, you will get a “terminate called without an active exception” error. Then cause unexpected errors further on.
In Linux and Windows, the exception thrown in destructor will be caught by system. Then the program terminates
Continue reading Not a good idea to throw exceptions in destructor in C++