Force Chrome to use socks5 proxy for DNS

Right now, there's no GUI interface for doing this. You need to start Chrome with the following flags:
--proxy-server="socks5://127.0.0.1:1080" --host-resolver-rules="MAP * 127.0.0.1"

Compile octave

Latest version of octave needs texinfo and newer version of gcc.

1.  Install gcc 4.7.1. gcc needs additional 3 components which have to be downloaded separatedly:

ftp://ftp.gnu.org/gnu/gmp/gmp-4.3.2.tar.gz
http://www.mpfr.org/mpfr-2.4.2/mpfr-2.4.2.tar.gz

http://www.multiprecision.org/mpc/download/mpc-0.8.1.tar.gz

unzip and copy them to gmp mpfr and mpc or gcc-4.7.1 source dir

mkdir ~/gcc-4.7.1

cd ~/gcc-4.7.1

~/downloads/gcc-4.7.1/configure  --enable-languages=all

make

sudo make install

2. Install texinfo

wget http://ftp.gnu.org/gnu/texinfo/texinfo-4.13.tar.gz

./configure

make

sudo make install

3. Install blas and lapack. On my environment, this is done by:

yum install blas

yum install lapack

And for me, I have to manually create a sym link libblas.so and liblapack.so as octave configuration cannot find the versioned so.

sudo ln -s libblas.so.3.0.3 /usr/lib64/libblas.so

sudo ln -s liblapack.so.3.0.3 /usr/lib64/liblapack.so

4. Install gnuplot-4.4

5. Install octave

cd octave-3.6.2

LD_RUN_PATH=/usr/local/lib64 LDFLAGS=-L/usr/local/lib64 ./configure --without-curl

LD_RUN_PATH=/usr/local/lib64 make -j 8

You may need to use different directories other than /usr/local/lib64 depending on where your blas/lapack/gfortran  libraries are located. If error happens, look at config.log to get more detail.

Creating and inserting into bucketed table

The clause for bucketing is:

[CLUSTERED BY (col_name, col_name, ...) [SORTED BY (col_name [ASC|DESC], ...)] INTO num_buckets BUCKETS]

The CLUSTERED BY and SORTED BY creation commands do not affect how data is inserted into a table – only how it is read. This means that users must be careful to insert data correctly by specifying the number of reducers to be equal to the number of buckets, and using CLUSTER BY and SORT BY commands in their query.

According to https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL+BucketedTables, with hive.enforce.bucketing=true, we don't need CLUSTER BY clause in the insert query. This is NOT correct. We still need CLUSTER BY in insert query.

What hive.enforce.bucketing does is "DISTRIBUTE BY". In order to do sorting automatically, we need "hive.enforce.sorting=true" or have CLUSTER BY in the insert query.

So what "CLUSTERED BY" in the table definition means is "DISTRIBUTE BY" and hive.enforce.bucketing only enforces "DISTRIBUTE BY".

Memory units

Different units for size are used in different contexts.

context           unit
ps                1024 bytes
cat /proc/meminfo 1024 bytes
free              1024 bytes
du                1024 bytes
ls -l             1 byte

compile mpich2

If you are using gcc version >= 4.3 to compile mpich2-1.3, which can be downloaded from http://www.mcs.anl.gov/research/projects/mpich2, you are likely to get tons of multiple definition errors. It took me quite a while to figure out the reason and the solution. This is caused by the --std=gnu99 used in hwloc. But using gnu99 will change the meaning of "extern inline" used in many c header files as explained in http://gcc.gnu.org/gcc-4.3/porting_to.html. Knowing this, the solution is quite simple: using the following command to configure:

CFLAGS=-fgnu89-inline ./configure

Effective alternative minimum tax bracket

2010 AMT bracket for the alternative minimum taxable income (AMT income)
assumming no qualified dividend or long term capital gain.

from	to	bracket
0	72,450	0
72,450	150,000	0.26
150,000	227,960	0.325
227,960	439,800	0.35
439,800	above	0.28

The strange thing is that the tax rate decreases for high AMT income. This is due to the fact that the "Exemption Amount" (Form 6251 line 29) is reduced when the AMT income is between 150,000 and 439,800.

References:

Form 6251

Form 6251 Instruction

rogue virus leading to antispy-guide.net

My wife's computer was infected by a rogue virus. It's constantly asking to buy anti-virus software from antispy-guide.net. And it blocked the execution of other program by saying they are infected.

The only exception is browser. You can still open a browser. Apparently, they don't want to block the way so that the infected user can purchase their software.

Here is how I dealt with it:

In explorer, copy \windows\system32\taskmgr.exe to some other place. Then rename it as firefox.exe and run it. Now the task manager appears. In the task manager find and kill a process with a very strange name which unfortunately I forgot what exactly it is. And I also deleted the corresponding .exe file from the file system.

Now everything is back to normal. I am not sure this is a permanent fix. But so far so good.

Increase limit on RLIMIT_NOFILE or other resources

Use setrlimit() to change the soft limit. But there is a hard limit which the setrlimit can not increase beyond.

In order to change the hard limit, you need to change the setting in following file
/etc/security/limits.conf

The syntax of the lines is as follows:

[domain] [type] [item] [value]

Use man limits.conf to see detailed explanation.

You can use command 'lsof -p [pid]' to see files opened by process pid.

Install Gnome On centos machine

Citing from

http://wiki.centos.org/FAQ/CentOS5#head-e99a7921ab6ce47e1cbf7d8cc8cadecf92b7ce94


yum --exclude=nautilus-sendto groupinstall "GNOME Desktop Environment"

NX broken session

If the remote server is restarted during an NX session, then you will encounter error when establishing a new session. You need to go to /usr/NX/var/db/running and delete files in the directory.

Passing Special Characters to Commands

Citing from The Linux Cookbook: Tips and Techniques for Everyday Use

Some characters are reserved and have special meaning to the shell on their own. Before you can pass one of these characters to a command, you must quote it by enclosing the entire argument in single quotes (`'').

For example, here's how to pass `Please Stop!' to a command:

'Please Stop!'
When the argument you want to pass has one or more single quote characters in it, enclose it in double quotes, like so:

"Please Don't Stop!"
To pass special characters as a string, give them as:

$'string'
where string is the string of characters to be passed. Special backslash escape sequences for certain characters are commonly included in a string, as listed in the following table.
ESCAPE SEQUENCE DESCRIPTION
\a Alert (rings the system bell).
\b Backspace.
\e Escape.
\f Form feed.
\n Newline.
\r Carriage return.
\t Horizontal tab.
\v Vertical tab.
\\ Backslash.
\NNN Character whose ASCII code is NNN in octal (base 8).
To demonstrate the passing of special character sequences to tool, the following examples will use the figlet tool, which displays the text you give as an argument in a "font" made up of text characters (see Horizontal Text Fonts).

To pass a backslash character as an argument to figlet, type:
$ figlet $'\\' [RET]
To pass a form feed character followed by a pilcrow sign character (octal character code 266) to figlet, type:
$ echo $'\f\266' [RET]

Binary numerical file IO in PERL

#following is a simple example
open FP, '>a.bin';
binmode FP; #make it binary file
@values=(3.2,3.3,3.4); #list of floating values
$a=pack 'f3' , @values; #pack as 32bit floating point value
#use 'd' for 64bit floating point
syswrite(FP,$a,12); #save to file
close FP;

US Government Balance

Federal Reserve balance sheet: http://www.federalreserve.gov/releases/h41/current/h41.htm

US Treasury Monthly Statement: http://www.fms.treas.gov/mts/

Styling form file input

Due to certain security considerations, it is very difficult to change the style of file input.
Here is a good post on how to do it.
http://www.quirksmode.org/dom/inputfile.html

Following is quoted from above article:

1. Take a normal < type="file">
2. To this same parent element, add a normal <> and an image, which have the correct styles. Position these elements absolutely, so that they occupy the same place as the < type="file">.
3. Set the z-index of the < type="file"> to 2 so that it lies on top of the styled input/image.
4. Finally, set the opacity of the < type="file"> to 0. The < type="file"> now becomes effectively invisible, and the styles input/image shines through, but you can still click on the "Browse" button. If the button is positioned on top of the image, the user appears to click on the image and gets the normal file selection window.
   (Note that you can't use visibility: hidden, because a truly invisible element is unclickable, too, and we need the < type="file"> to remain clickable)
5. When the user has selected a file, the visible, fake input field should show the correct path to this file, as a normal < type="file"> would. It's simply a matter of copying the new value of the < type="file"> to the fake input field, but we need JavaScript to do this.

Linking with static runtime libraries with MFC

In Visual C++, due to some conflicts between libcmt.lib and nafxcw.lib, you need to
make following changes in Linker->Input

Additional Dependencies: nafxcw.lib libcmt.lib
Ignore specific libraries: libcmt.lib nafxcw.lib

Using C99 support in Intel Compiler

C99 only works for C. Not C++. So the code must be compiled as C code not C++ code.

javascript variable scope

The scope of a variable is the current function or, for variables declared outside a function, the current application.
Aassigning a value to an undeclared variable implicitly declares it as a global variable.

Each function is associated with its closure chain
A variable is undefined if cannot be found in the current closure chain,
and the access attemp will generate error.

The global function 'eval' uses current closure chain to evaluate the string.
If a function is still accessible, its function closure chain is still in memory.

Image flicker in IE6

This is due to IE 6 keeps check for the background image specified in css property everty time the element is moved over. Note that IE 5 or IE 7 do not have this problem.

A good post about this problem is at http://www.mister-pixel.com/

The solution is to add following javascript code inside the HEAD of the page:
try {
document.execCommand("BackgroundImageCache", false, true);
} catch(err) {}

This fix works only with Internet Explorer 6, Service Pack 1 or newer.
Also, the fix does not apply if you change the background image on :hover. It only prevents the flicker of the same background image, when changing other rules inside the :hover state. But you can still change the background position.

Save file using different extensions in MS Word

Usually, MS Word will append a fixed extension for a given file type. If you want to use a different extension, you need to enclose the file name in quotes. For example, "textfile.dat" will force MS Word to use dat as extension.

Open a file by drag-and-drop in MS Word

Unlike many other editors, for MSWord, the file should be dropped in the menu area.
It should not be dropped in document area. If it's dropped in document area,
it will become an embedded file.