Understanding C++ memory and variables

#include <iostream>
using namespace std;
void f1 (int *j)
{
cout << "in f1() beginning-------------\n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j <<"\n";
    int l = 20;
    int *k = &l;
    j = k;
    //k = 0;
    cout << "in f1():======================\n";
    cout << "       l addr is: " << &l << " value is: " << l << "\n";
    cout << "       k addr is: " << &k << " is pointed to addr: " << k << " value is: " << *k << "\n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j <<"\n\n\n";
}

void f2(int **j)
{
    cout << "in f2() beginning-------------\n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j <<"\n";
    cout << "       the value is an address and the exact data is: " << **j << "\n";

    int l = 20;
    int *k = &l;
    *j = k;
    //k = 0;
    cout << "in f2():======================\n";
    cout << "       l addr is: " << &l << " value is: " << l << "\n";
    cout << "       k addr is: " << &k << " is pointed to addr: " << k << " value is: " << *k << "\n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j <<"\n";
    cout << "       the value is an address and the exact data is: " << **j << "\n\n\n";
}

int main()
{
    int i=10;
    int *j = &i;

    cout << "before f1() in main:\n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j << "\n\n";

    f1(j);
    cout << "after f1() in main: \n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j << "\n\n";

    f2(&j);
    cout << "after f2() in main: \n";
    cout << "       j addr is: " << &j << " is pointed to addr " << j << " value is: " << *j << "\n\n";

    return 0;
}

results:

before f1() in main:

      j addr is: 0x28fea8 is pointed to addr 0x28feac value is: 10

in f1() beginning-------------

      j addr is: 0x28fe90 is pointed to addr 0x28feac value is: 10

in f1():======================

      l addr is: 0x28fe7c value is: 20

      k addr is: 0x28fe78 is pointed to addr: 0x28fe7c value is: 20

      j addr is: 0x28fe90 is pointed to addr 0x28fe7c value is: 20

after f1() in main:

      j addr is: 0x28fea8 is pointed to addr 0x28feac value is: 10

in f2() beginning-------------

      j addr is: 0x28fe90 is pointed to addr 0x28fea8 value is: 0x28feac

      the value is an address and the exact data is: 10

in f2():======================

      l addr is: 0x28fe7c value is: 20

      k addr is: 0x28fe78 is pointed to addr: 0x28fe7c value is: 20

      j addr is: 0x28fe90 is pointed to addr 0x28fea8 value is: 0x28fe7c

      the value is an address and the exact data is: 20

after f2() in main:

      j addr is: 0x28fea8 is pointed to addr 0x28fe7c value is: 20

How to install python packages on Windows 7

Brief steps:

1. Download a package

2. Extract the package to a folder_pkg

3. Open Windows Command Prompt

4. Go to the folder_pkg

5. > python setup.py install

Then done. Check PythonHomeDir/Lib/site-packages

Useful packages:

1. simplejson: https://pypi.python.org/pypi/simplejson

2. XlsxWriter: https://pypi.python.org/pypi/XlsxWriter

An Detailed Example for installing XlsxWriter Package (TODO)

高峰体验

[摘] 一个徒步登山者，费尽千辛万苦，克服许多的艰难险阻，每一步都挣扎在生死边缘。开始的时候，还有很好的现实感，知道山知道水，攀登中还会有幽默和笑语。慢 慢的，躯体的痛苦，情绪的沉抑，心身的耗竭让你忘却了行为的意义，甚至怀疑攀登的价值和现实性，你的内心挤满了渴望与逃避，冒险与胆怯、放弃与坚持的双向 冲突，知觉变得凝重而迟缓，现实感消隐，意识逐步的缩窄。再后来，你的思想似乎停滞，感觉麻木，忘了自己是谁，在做什么和为什么要做，只是机械地向上走。 你的意识界沉静而虚无，只有心灵那一丝光亮，仍在坚持和闪耀着。        终于，你到达了那高耸卓绝的山顶，按理说积压太长的期待会给你带来像爆炸一般的狂喜，但却没有发生。你似乎忘却了自我，忘却了存在，时间和空间消融在一 起，没有边界，四周只有一片纯净的虚空，深邃而神秘。你甚至会有一瞬的迷茫，不知道你接下来要做什么？这时，一种像海潮般的愉悦和满足感从遥远的心灵深处 释放、溢出、扩展，伴随着高峰上的洁净、安详，和谐席卷了你，你似乎听见了心灵的笑声，品尝到生命融入那种永恒与无限的感觉。慢慢的海潮过去，你的内心仍 充满着充沛的活力和美妙无比的欣喜，灵感激荡，思想饱满而充实。在以后很长的日子里，你对自我的态度和对世界的感觉已经完全的不同。每当遇到困难的时候， 回忆那不平凡的一刻，你的内心依然会荡漾出坚毅、活力和创造力，成为你自由、自信、自强不息的精神源泉。

[摘马斯诺高峰体验]

Sed Command Basics

Description: the most command parameter of sed command is 's', which stands for substitute.
Format: sed 'PARAM/REGEXP/REPLACEMENT/FLAG' filename
        It searches for matched patterns (by REGEXP) and replaces it with REPLACEMENT.  PARAM and FLAG decides which match is replaced.

Examples:

1. Replace every first match in a line 

  $ cat sed_cmd_study.txt
  This is to study sed command in Linux system.
  Actually, this is in a cygwin terminal.
  Here are some list of stuff that I am interested:
  Linux Hacking
  C programming and C++ programming
  Python programming and Perl programming
  Photoshop applications and design
  And all the other related stuffs


  $ sed 's/programming/coding/' sed_cmd_study.txt
  This is to study sed command in Linux system.
  Actually, this is in a cygwin terminal.
  Here are some list of stuff that I am interested:
  Linux Hacking
  C coding and C++ programming
  Python coding and Perl programming
  Photoshop applications and design
  And all the other related stuffs
    [NOTE]: in this case, the original file is not modified


    2.  Replace every matches in file
  $ sed 's/programming/coding/g' sed_cmd_study.txt
  This is to study sed command in Linux system.
  Actually, this is in a cygwin terminal.
  Here are some list of stuff that I am interested:
  Linux Hacking
  C coding and C++ coding
  Python coding and Perl coding
  Photoshop applications and design
  And all the other related stuffs
     
    [NOTE]: in this case, the original file is not modified


     3. Only replace the 2nd occurrence of a line in file
  $ sed 's/programming/coding/2' sed_cmd_study.txt
  This is to study sed command in Linux system.
  Actually, this is in a cygwin terminal.
  Here are some list of stuff that I am interested:
  Linux Hacking
  C programming and C++ coding
  Python programming and Perl coding
  Photoshop applications and design
  And all the other related stuffs
     
    [NOTE]: in this case, the original file is not modified

     4.  Replace all the matches and write the modified lines in a file
  $ sed 's/programming/coding/gw output.txt' sed_cmd_study.txt
  This is to study sed command in Linux system.
  Actually, this is in a cygwin terminal.
  Here are some list of stuff that I am interested:
  Linux Hacking
  C coding and C++ coding
  Python coding and Perl coding
  Photoshop applications and design
  And all the other related stuffs

  $ cat output.txt
  C coding and C++ coding
  Python coding and Perl coding


     5. Delete last X number of characters from each line
  $ sed 's/...$//g' sed_cmd_study.txt
  This is to study sed command in Linux syst
  Actually, this is in a cygwin termin
  Here are some list of stuff that I am interest
  Linux Hack
  C programming and C++ programm
  Python programming and Perl programm
  Photoshop applications and des
  And all the other related stu