emocias

2014-04-28T20:55:00.002-04:00

Compile Qt 5 64bit library with Visual Studio 2010 Professional

Qt does not support 64bit library officially, but you can build that.

Although 64bit library is unstable, it is useful to establish 64bit environment with QT and Visual Studio 2010 professional. First of all, Visual Studio 2010 professional is installed on you system. Steps are as followings:

Install Perl if Qt version is more than 4.8.0 because it use Perl to configure building.
Download and install qt5(visual studio 2010).
Open Visual Studio x64 Win64 Command Prompt (2010)

Location: Start->All Programs->Microsoft Visual Studio 2010->Visual Studio Tools->Visual Studio x64 Win64 Command Prompt (2010)

Set up environmental variables
> Set QTDIR=C:\Qt\5.2.1\qtbase > Set QMAKESPEC=win32-msvc2010
Update PATH variable to include %QTDIR%\bin in System environments
Download the latest version of jom which speeds up Visual C++ Qt Builds by supporting parallel processes.
Extract jom files to C:\Qt\jom folder
Run following commands in it (every line is a different command: type it then press Enter):
> cd c:\Qt\5.2.1\qtbase > configure -debug-and-release -opensource -platform win32-msvc2010 -opengl desktop -nomake examples > ..\jom\jom.exe -j N

Where N is number of CPU cores you want to utilize for Qt compilation. Larger is better.
Run the following command.

> ..\jom\jom.exe clean
One can safely shrink its size by deleting temporary files created during the process. Note that PDB files will be deleted too.

Download and install Qt Visual Studio Add-in.
Run Visual Studio 2010. Integrate just compiled Qt to IDE using menu Qt > Qt Options > Qt Versions > Add

Getting MAC address on the linux by using C++

2013-05-14T13:38:00.004-04:00

After getting a list of network interfaces,
This code will print MAC address per each interface except loopback.

#include <sys/ioctl.h>
#include <net/if.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>

#define MAC_STRING_LENGTH 13

int main()
{
char mac_address[MAC_STRING_LENGTH];

struct ifreq ifr;
struct ifconf ifc;
char buf[1024];
int success = 0;

int sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock == -1) { return -1;}

ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
if (ioctl(sock, SIOCGIFCONF, &ifc) == -1)
{
std::cout << "error" << std::endl;
return 0;
}

struct ifreq* it = ifc.ifc_req;
const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));

for (; it != end; ++it) {
std::cout << it->ifr_name << std::endl;

strcpy(ifr.ifr_name, it->ifr_name);
if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback
if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {

for (int i = 0; i < 6; ++i)
snprintf(mac_address+i*2,MAC_STRING_LENGTH-i*2,"%02x",(unsigned char) ifr.ifr_addr.sa_data[i]);
std::cout << mac_address << std::endl;

}
}
}
else {
std::cout << "error" << std::endl;
return 0;
}
}
}

vncserver on Debian

2013-02-09T22:18:00.002-05:00

vncserver allows you to access the remote desktop where the operating system is Windows or Linux. This article will describe how to set up vncserver on linux and use vncviewer. Especially I have tested on Debian Squeeze and used tightvncserver which is one of vnc servers.

[Server Side]

First of all, you need to set up vncserver on linux.
1. installation of vncserver
# apt-get install tightvncserver

After installing vncserver, you need to configure several options.

# tightvncserver :1
# tightvncserver -kill :11
( This command will initialize the default options and kill the vncserver process)

By editing the following file, set up options.
# vi ~/.vnc/xstartup
xsetroot -solid grey
x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &

gnome-session &

"gnome-session &" option supports the desktop based on GNOME.

Finally, you can start vncserver like this.

# vncserver :1 -geometry 1920x1200 -depth 24 -dpi 95

":1" is the display number, "-geometry 1920x1200" is the display resolution, "-depth 24" is the color depth, and "-dpi 95" is the font size. Usually the desktop accessed by vncviewer has the small font size. So, you need to reset the font size on the server by "-dpi" option.

[Client Side]

To access the vnc server, you can use TightVNC client which is a free remote control software package.

Input a remote host in the edit box "Remote Host:" like "xxx.xxx.xxx:1".

After an IP information, you should attach a display number which has already been configured when starting vncserver.

[Share the desktop]

Here is another tip.

If you want to share the same desktop view between the linux server and the client,you have to use "x11vnc" command.

On the server side, type the following command.

$ x11vnc -display :0

After that, type a remote host in TightVNC client.

Only enter IP or host name.

Fail to start Oracle Enterprise Manager 11g

2012-10-25T13:58:00.001-04:00

I will post how to recover Oracle Enterprise Manager (OEM) for 11g when failing to start OEM after changing the password of sysdba. Normally OEM is working well. However, OEM has a problem after changing the password sometimes. To fix this problem, you can reconfigure the setting of OEM.
Here is a way.
First of all, type the following command.

oracle> emca -deconfig dbcontrol db
oracle> emctl start dbconsole
-> after doing this command, if OEM is not working, try to run this command.
oracle> emca -config dbcontrol db

Enter the following information:
Database SID: bm
Listener port number: 1521
Listener ORACLE_HOME [ /db/app/oracle/product/11.2.0/dbhome_1 ]:
Password for SYS user:
Password for DBSNMP user:
Password for SYSMAN user:

Enter your database SID, listener port, oracle home, and the passwords of SYS, DBSNMP, SYSMAN.

This command will reconfigure all the settings for OEM.

Compile Qt 4.8.2 64bit library with Visual Studio 2010 Professional

2012-08-09T15:15:00.001-04:00

Qt does not support 64bit library officially, but you can build that.

Install Perl if Qt version is more than 4.8.0 because it use Perl to configure building.
Download and install Qt libraries 4.8.2 for Windows (VS 2010).
Open Visual Studio x64 Win64 Command Prompt (2010)

Location: Start->All Programs->Microsoft Visual Studio 2010->Visual Studio Tools->Visual Studio x64 Win64 Command Prompt (2010)

Set up environmental variables
> Set QTDIR=C:\Qt\4.7.1 > Set QMAKESPEC=win32-msvc2010
Update PATH variable to include %QTDIR%\bin in System environments
Download the latest version of jom which speeds up Visual C++ Qt Builds by supporting parallel processes.
Extract jom files to C:\Qt\jom folder
Run following commands in it (every line is a different command: type it then press Enter):
> cd c:\Qt\4.7.1 > configure -debug-and-release -opensource -platform win32-msvc2010 -opengl desktop > ..\jom\jom.exe -j N

Where N is number of CPU cores you want to utilize for Qt compilation. Larger is better.
Run the following command.

> ..\jom\jom.exe clean
One can safely shrink its size by deleting temporary files created during the process. Note that PDB files will be deleted too.

Download and install Qt Visual Studio Add-in.
Run Visual Studio 2010. Integrate just compiled Qt to IDE using menu Qt > Qt Options > Qt Versions > Add

Remarks

* Jom is nmake replacement for Qt compilation on multi-core CPU. Its parameter -j N allows to setup number of parallel processes for compilation. Number of physical CPU cores is a good choice for N.

[Oracle] Identify the locked row id in table described

2012-06-19T12:08:00.003-04:00

This sql will get locked id in Table <table_name>

select dbms_rowid.rowid_create(1,row_wait_obj#, row_wait_file#, row_wait_block#, row_wait_row#) from v$session where sid = (select s.sid from dba_objects, v$lock s where object_id = s.ID1 and object_name = '<table_name>');

Environment variables on Oracle 11g Release 2

2012-05-25T16:43:00.000-04:00

Setting up environment variables

$ vi .bashrc
# add ORACLE_HOME, ORACLE_BASE and ORACLE_SID
# example
export ORACLE_BASE=/db/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1
export ORACLE_SID=oracle_sid

Test

$ sqlplus /nolog
SQL> connect / as sysdba
SQL> startup
ORA-01078: failure in processing system parametersLRM-00109: could not open parameter file 'anywhere'

If you are facing the above error while startup of oracle, possible reasons might be the init{ORACLE_SID}.ora file not accessible by oracle user. To solve this problem, you can get your pfile at the location $ORACLE_BASE/admin/$ORACLE_SID/pfile/. A typical file name is init.ora.{NUMBER}. From that location, make a spfile by the following:

$ORACLE_BASE=/db/app/oracle/ and $ORACLE_SID=ora_sid
$sqlplus /nolog
SQL> connect / as sysdba
SQL> create spfile from pfile='/db/app/oracle/admin/ora_sid/pfile/init.ora.{NUMBER}
File created.
SQL> startup

Using Key simulation in MFC

2012-05-25T16:15:00.002-04:00

Sometimes, we need to send keys to another process when developing MFC application.
We called sending keys "Key simulation"
For this purpose, we can use the function "SendInput" as a function of MFC.
Here I will describe an example. So, see the function description.

We have to get a window handle to send keys.
In MFC, there are several methods for this. Here I will use FindWindowEx method.
When finding the specific window handle, you can describe "class name" or "Window title name"
I think "Window title name" is more convenient.

// Get window handle

HWND hWindow = ::FindWindowEx(NULL, NULL, "Class Name", 0);
or
HWND hWindow = ::FindWindowEx(NULL, NULL, 0, "Window title name");

// Get thread and process id

PROCESS_INFORMATION pi;
pi.dwThreadId = ::GetWindowThreadProcessId(hWindow, &(pi.dwThreadId));

SendKey(WORD('A'), MapVirtualKey('A',0), pi);

Refer two methods 'SendKey' and 'SendCtrlShiftKey'

void SendKey(WORD vk, WORD scan, PROCESS_INFORMATION pi)
{

INPUT is;

is.type = INPUT_KEYBOARD; //INPUT_KEYBOARD = 1
is.ki.time = 0;

is.ki.wVk = vk;
is.ki.wScan = scan;
is.ki.dwFlags = NULL;
is.ki.dwExtraInfo = NULL;

SendInput(1, &is, sizeof(INPUT)); // Key down
WaitForInputIdle( pi.hProcess, INFINITE );

is.ki.wVk = vk;
is.ki.dwFlags = KEYEVENTF_KEYUP;
is.ki.wScan = scan;
is.type = INPUT_KEYBOARD;

SendInput(1, &is, sizeof(INPUT)); // Key up
WaitForInputIdle( pi.hProcess, INFINITE );
}

void SendCtrlShiftKey(WORD vk, PROCESS_INFORMATION pi)
{
INPUT inp[6];
short Ecnt = 0x00;

// VK_CONTROL down.
inp[0].ki.time = NULL;
inp[0].type = INPUT_KEYBOARD;
inp[0].ki.dwExtraInfo = NULL;
inp[0].ki.dwFlags = NULL;
inp[0].ki.wVk = VK_CONTROL;
inp[0].ki.wScan = MapVirtualKey(VK_CONTROL,0);

// VK_SHIFT down.
inp[1].ki.time = NULL;
inp[1].type = INPUT_KEYBOARD;
inp[1].ki.dwExtraInfo = NULL;
inp[1].ki.dwFlags = NULL;
inp[1].ki.wVk = VK_SHIFT;
inp[1].ki.wScan = MapVirtualKey(VK_SHIFT,0);

// Character Key down.
inp[2].ki.time = NULL;
inp[2].type = INPUT_KEYBOARD;
inp[2].ki.dwExtraInfo = NULL;
inp[2].ki.dwFlags = NULL;
inp[2].ki.wVk = vk;
inp[2].ki.wScan = MapVirtualKey(vk,0);

// VK_CONTROL up.
inp[3].ki.time = NULL;
inp[3].type = INPUT_KEYBOARD;
inp[3].ki.dwExtraInfo = NULL;
inp[3].ki.dwFlags = KEYEVENTF_KEYUP;
inp[3].ki.wVk = VK_CONTROL;
inp[3].ki.wScan = MapVirtualKey(VK_CONTROL,0);

// VK_SHIFT up.
inp[4].ki.time = NULL;
inp[4].type = INPUT_KEYBOARD;
inp[4].ki.dwExtraInfo = NULL;
inp[4].ki.dwFlags = KEYEVENTF_KEYUP;
inp[4].ki.wVk = VK_SHIFT;
inp[4].ki.wScan = MapVirtualKey(VK_SHIFT,0);

// Character Key up.
inp[5].ki.time = NULL;
inp[5].type = INPUT_KEYBOARD;
inp[5].ki.dwExtraInfo = NULL;
inp[5].ki.dwFlags = KEYEVENTF_KEYUP;
inp[5].ki.wVk = vk;
inp[5].ki.wScan = MapVirtualKey(vk,0);

SendInput(1,inp,sizeof(INPUT)); // VK_CONTROL down
WaitForInputIdle( pi.hProcess, INFINITE );

SendInput(1,&inp[1],sizeof(INPUT)); // VK_SHIFT down
WaitForInputIdle( pi.hProcess, INFINITE );

SendInput(1,&inp[2],sizeof(INPUT)); // Key down
WaitForInputIdle( pi.hProcess, INFINITE );

SendInput(1,&inp[5],sizeof(INPUT)); // Key up
WaitForInputIdle( pi.hProcess, INFINITE );

SendInput(1,&inp[4],sizeof(INPUT)); // VK_SHIFT up
WaitForInputIdle( pi.hProcess, INFINITE );

SendInput(1,&inp[3],sizeof(INPUT)); // VK_SHIFT up
WaitForInputIdle( pi.hProcess, INFINITE );
}

Cydia

2012-05-25T15:55:00.000-04:00

[Cydia Source List]

http://sinfuliphonerepo.com
http://cydia.hackulo.us
http://repo.hackyouriphone.org
http://repo.biteyourapple.net
http://cydia.xsellize.com
http://repo.insanelyi.com

[Essential applications]
1. mobileterminal: change password [alpine]
2. OpenSSH
3. SBSetting
4. CyDelete
5. afc2add
6. Installous 4
7. AppSync 5.0+
8. iFile

Restoring Grub2 from the booting cd-rom

2011-10-11T18:28:00.000-04:00

In case of Debian Squeeze,
after going into the install steps, proceed until loading the device drivers.
Then, if pushed Ctrl+Alt+F2, you can get the command prompt.

# fdisk -l
# mount -t ext4 /dev/XXX /chroot
# mount --bind /dev /chroot/dev
# mount -t sysfs none /chroot/sys
# mount -t proc none /chroot/proc
# chroot /chroot/
# grub-install /dev/XXX

Single instance in MFC

2011-10-11T09:37:00.000-04:00

Sometimes you want to make your application only with a single instance.
Unfortunately MFC don't provide any APIs. However, there is the simplest method by MUTEX.

First, you create the globally unique identifier (GUID) to create MUTEX.
MFC provides creating GUID: Tools-Create GUID.
after creating it, just copy and paste in your code.

The following code located in InitInstance() of MFC.

CString stringGUID = L"........";
HANDLE hMutex = CreateMutex(NULL, TRUE, stringGUID);
if( GetLastError() == ERROR_ALREADY_EXISTS )
{
CloseHandle(hMutex);
return FALSE;
}

libconfig - C/C++ Configuration File Library

2011-06-03T12:00:00.002-04:00

Libconfig is a great library which can process configuration files base on structured format such as XML.
According tohttp://www.hyperrealm.com/libconfig/, this file format is more compact and more readable than XML. Advantages are the follows:

type-aware: by parser, it is automatically bound to the appropriate type such as int, float, array, and string.
support both the C and C++
works on various operating systems: GNU/Linux, Mac OS X, Solaris, FreeBSD, and Windows (2000, XP, and later)

I tested whether or not it works on Windows 7 and Visual studio 2005. The result is very successful.
Here is a sample configuration file.

#----------------------------
# Example Configuration File
#---------------------------
#

application:
{

 /* This section defines some settings for our
  * main application window, such as size and
  * position.
  */

  window:
  {
    title = "My Application";
    size = { /* width */ w = 640; /* height */ h = 480; };
    pos = { x = 350; y = 250; };
  };

  a = 5;
  b = 6;
  ff = 1E6;
  test-comment = "/* hello\n \"there\"*/";

  test-long-string = "A very long string that spans multiple lines. "
  /* but wait, there's more... */ "Adjacent strings are automatically"
  " concatenated.";

  test-escaped-string = "\"This is\n a test.\"";

  group1:
  {
    x = 5;  y = 10;
    my_array = [ 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 ];
    flag = TRUE;

    group2: { zzz = "this is a test"; };

    states = [ "CT", // Connecticut
  "CA", // California
  "TX", // Texas
  "NV", // Nevada
  "FL"  // Florida
    ];
  };

  /* this would cause an error */
  // a = "hi!";
};

binary = [ 0xAA, 0xBB, 0xCC ];

list = ( ( "abc", 123, true ), 1.234, ( /* an empty list */ ) ,[ 1, 2, 3 ],
    { a = (1, 2, true); } );

books = ( "inventory",
          { title  = "Treasure Island";
            author = "Robert Louis Stevenson";
            price  = 29.99;
            qty    = 5; },
          { title  = "Snow Crash";
            author = "Neal Stephenson";
            price  = 9.99;
            qty    = 8; },
          { } );

# miscellaneous stuff

misc:
{
  port = 5000;
  pi = 3.14159265;
  enabled = FALSE;
  mask = 0xAABBCCDD;
  unicode = "STARGÎ›ÌŠTE SG-1"; // UTF-8 string
  bigint = 9223372036854775807L;
  bighex = 0x1122334455667788L;
};


### eof

As shown in the sample configuration above, this is so very powerful that I love the libconfig library.
Finally, I provide a sample code to read a configuration file.


#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <libconfig.h++>

using namespace std;
using namespace libconfig;

// This example reads the configuration file 'example.cfg' and displays
// some of its contents.

int main(int argc, char **argv)
{
  Config cfg;

  // Read the file. If there is an error, report it and exit.
  try
  {
    cfg.readFile("example.cfg");
  }
  catch(const FileIOException &fioex)
  {
    std::cerr << "I/O error while reading file." << std::endl;
    return(EXIT_FAILURE);
  }
  catch(const ParseException &pex)
  {
    std::cerr << "Parse error at " << pex.getFile() << ":" << pex.getLine()
              << " - " << pex.getError() << std::endl;
    return(EXIT_FAILURE);
  }

  // Get the store name.
  try
  {
    string name = cfg.lookup("name");
    cout << "Store name: " << name << endl << endl;
  }
  catch(const SettingNotFoundException &nfex)
  {
    cerr << "No 'name' setting in configuration file." << endl;
  }

  const Setting& root = cfg.getRoot();

  // Output a list of all books in the inventory.
  try
  {
    const Setting &books = root["inventory"]["books"];
    int count = books.getLength();

    cout << setw(30) << left << "TITLE" << "  "
         << setw(30) << left << "AUTHOR" << "   "
         << setw(6) << left << "PRICE" << "  "
         << "QTY"
         << endl;

    for(int i = 0; i < count; ++i)
    {
      const Setting &book = books[i];

      // Only output the record if all of the expected fields are present.
      string title, author;
      double price;
      int qty;

      if(!(book.lookupValue("title", title)
           && book.lookupValue("author", author)
           && book.lookupValue("price", price)
           && book.lookupValue("qty", qty)))
        continue;

      cout << setw(30) << left << title << "  "
           << setw(30) << left << author << "  "
           << '$' << setw(6) << right << price << "  "
           << qty
           << endl;
    }
    cout << endl;
  }
  catch(const SettingNotFoundException &nfex)
  {
    // Ignore.
  }

  // Output a list of all books in the inventory.
  try
  {
    const Setting &movies = root["inventory"]["movies"];
    int count = movies.getLength();

    cout << setw(30) << left << "TITLE" << "  "
         << setw(10) << left << "MEDIA" << "   "
         << setw(6) << left << "PRICE" << "  "
         << "QTY"
         << endl;

    for(int i = 0; i < count; ++i)
    {
      const Setting &movie = movies[i];

      // Only output the record if all of the expected fields are present.
      string title, media;
      double price;
      int qty;

      if(!(movie.lookupValue("title", title)
           && movie.lookupValue("media", media)
           && movie.lookupValue("price", price)
           && movie.lookupValue("qty", qty)))
        continue;

      cout << setw(30) << left << title << "  "
           << setw(10) << left << media << "  "
           << '$' << setw(6) << right << price << "  "
           << qty
           << endl;
    }
    cout << endl;
  }
  catch(const SettingNotFoundException &nfex)
  {
    // Ignore.
  }

  return(EXIT_SUCCESS);
}

libconfig - C/C++ Configuration File Library

2011-06-03T11:46:00.001-04:00

type-aware: by parser, it is automatically bound to the appropriate type such as int, float, array, and string.
support both the C and C++
works on various operating systems: GNU/Linux, Mac OS X, Solaris, FreeBSD, and Windows (2000, XP, and later)

I tested whether or not it works on Windows 7 and Visual studio 2005. The result is very successful.
Here is a sample configuration file.

#----------------------------
# Example Configuration File
#---------------------------
#

application:
{

 /* This section defines some settings for our
  * main application window, such as size and
  * position.
  */

  window:
  {
    title = "My Application";
    size = { /* width */ w = 640; /* height */ h = 480; };
    pos = { x = 350; y = 250; };
  };

  a = 5;
  b = 6;
  ff = 1E6;
  test-comment = "/* hello\n \"there\"*/";

  test-long-string = "A very long string that spans multiple lines. "
  /* but wait, there's more... */ "Adjacent strings are automatically"
  " concatenated.";

  test-escaped-string = "\"This is\n a test.\"";

  group1:
  {
    x = 5;  y = 10;
    my_array = [ 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 ];
    flag = TRUE;

    group2: { zzz = "this is a test"; };

    states = [ "CT", // Connecticut
  "CA", // California
  "TX", // Texas
  "NV", // Nevada
  "FL"  // Florida
    ];
  };

  /* this would cause an error */
  // a = "hi!";
};

binary = [ 0xAA, 0xBB, 0xCC ];

list = ( ( "abc", 123, true ), 1.234, ( /* an empty list */ ) ,[ 1, 2, 3 ],
    { a = (1, 2, true); } );

books = ( "inventory",
          { title  = "Treasure Island";
            author = "Robert Louis Stevenson";
            price  = 29.99;
            qty    = 5; },
          { title  = "Snow Crash";
            author = "Neal Stephenson";
            price  = 9.99;
            qty    = 8; },
          { } );

# miscellaneous stuff

misc:
{
  port = 5000;
  pi = 3.14159265;
  enabled = FALSE;
  mask = 0xAABBCCDD;
  unicode = "STARGÎ›ÌŠTE SG-1"; // UTF-8 string
  bigint = 9223372036854775807L;
  bighex = 0x1122334455667788L;
};


### eof

As shown in the sample configuration above, this is so very powerful that I love the libconfig library.
Finally, I provide a sample code to read a configuration file.







#include <iostream>

#include <iomanip>

#include <cstdlib>

#include <libconfig.h++>




using namespace std;

using namespace libconfig;




// This example reads the configuration file 'example.cfg' and displays

// some of its contents.




int main(int argc, char **argv)

{

  Config cfg;




  // Read the file. If there is an error, report it and exit.

  try

  {

    cfg.readFile("example.cfg");

  }

  catch(const FileIOException &fioex)

  {

    std::cerr << "I/O error while reading file." << std::endl;

    return(EXIT_FAILURE);

  }

  catch(const ParseException &pex)

  {

    std::cerr << "Parse error at " << pex.getFile() << ":" << pex.getLine()

              << " - " << pex.getError() << std::endl;

    return(EXIT_FAILURE);

  }




  // Get the store name.

  try

  {

    string name = cfg.lookup("name");

    cout << "Store name: " << name << endl << endl;

  }

  catch(const SettingNotFoundException &nfex)

  {

    cerr << "No 'name' setting in configuration file." << endl;

  }




  const Setting& root = cfg.getRoot();




  // Output a list of all books in the inventory.

  try

  {

    const Setting &books = root["inventory"]["books"];

    int count = books.getLength();




    cout << setw(30) << left << "TITLE" << "  "

         << setw(30) << left << "AUTHOR" << "   "

         << setw(6) << left << "PRICE" << "  "

         << "QTY"

         << endl;




    for(int i = 0; i < count; ++i)

    {

      const Setting &book = books[i];




      // Only output the record if all of the expected fields are present.

      string title, author;

      double price;

      int qty;




      if(!(book.lookupValue("title", title)

           && book.lookupValue("author", author)

           && book.lookupValue("price", price)

           && book.lookupValue("qty", qty)))

        continue;




      cout << setw(30) << left << title << "  "

           << setw(30) << left << author << "  "

           << '$' << setw(6) << right << price << "  "

           << qty

           << endl;

    }

    cout << endl;

  }

  catch(const SettingNotFoundException &nfex)

  {

    // Ignore.

  }




  // Output a list of all books in the inventory.

  try

  {

    const Setting &movies = root["inventory"]["movies"];

    int count = movies.getLength();




    cout << setw(30) << left << "TITLE" << "  "

         << setw(10) << left << "MEDIA" << "   "

         << setw(6) << left << "PRICE" << "  "

         << "QTY"

         << endl;




    for(int i = 0; i < count; ++i)

    {

      const Setting &movie = movies[i];




      // Only output the record if all of the expected fields are present.

      string title, media;

      double price;

      int qty;




      if(!(movie.lookupValue("title", title)

           && movie.lookupValue("media", media)

           && movie.lookupValue("price", price)

           && movie.lookupValue("qty", qty)))

        continue;




      cout << setw(30) << left << title << "  "

           << setw(10) << left << media << "  "

           << '$' << setw(6) << right << price << "  "

           << qty

           << endl;

    }

    cout << endl;

  }

  catch(const SettingNotFoundException &nfex)

  {

    // Ignore.

  }




  return(EXIT_SUCCESS);

}

Windows 8: Building Video

2011-06-02T08:58:00.001-04:00

Microsoft revealed a new operating system, windows 8.
The below movie shows the working by Touch Screen.
Maybe, it is optimized for Tablet PC.

Automatically Scheduling of SyncToy

2011-06-01T20:02:00.000-04:00

SyncToy doesn't have the feature to allow user to schedule folders to run synchronization process.
But, we can use Task Scheduler of Windows 7.

[Procedure]

Click Task Scheduler, Location: Start menu - All Programs - Accessories - System Tools - Task Scheduler
Click Create Basic Task in the Actions
Type in a Name and Description
Click Next button
Select the frequency of when you want the task to start
Click Next button
Input date and times
Click Next button
Select Start a program
Click Next button
In Program/script, Locate the SyncToyCmd.exe
In Add arguments, Type -R which run all folder pairs that are active for run all. If you want to run just a single folder pair, add -R"Folder pair name" to the end of the command line
Click Next button

log4cplus - Logging library to C++ such as log4j

2011-06-01T10:41:00.003-04:00

log4cplus is the excellent logging library to C++ such as log4j.
You can see at log4cplus.sourceforge.net.
Current version is 1.0.4, released on January 2011.

I tested this library on Visual studio 2005.
It is based on Win32 platform, so you can easily build it.
The following example is to save logging information into a specified log file.

<Code Example>

#include <log4cplus/logger.h>
#include <log4cplus/configurator.h>
#include <log4cplus/fileappender.h>

using namespace log4cplus;

int main()
{
    SharedAppenderPtr myAppender(new FileAppender("LogFile.log"));
    BasicConfigurator config;
    config.configure();

    logger = Logger::getInstance("main");
    logger.addAppender(myAppender);
    logger.setLogLevel(ALL_LOG_LEVEL);

    LOG4CPLUS_WARN(logger, "Warning Test");

    return 0;
}

Centos - Sudoers file

2011-06-01T09:54:00.000-04:00

In Centos, to use the command "sudo", you add a user information to /etc/sudoers.

For example, Basically root is "root ALL=(ALL) ALL"

You can modify this file for new sudo user.
username ALL=(ALL)ALL

Noise Generation

2011-05-23T11:05:00.001-04:00

reference: http://homepages.inf.ed.ac.uk/rbf/HIPR2/noise.htm

Noise Generation

Common Names: Noise Generation

Brief Description

Real world signals usually contain departures from the ideal signal that would be produced by our model of the signal production process. Such departures are referred to as noise. Noise arises as a result of unmodelled or unmodellable processes going on in the production and capture of the real signal. It is not part of the ideal signal and may be caused by a wide range of sources, e.g. variations in the detector sensitivity, environmental variations, the discrete nature of radiation, transmission or quantization errors, etc. It is also possible to treat irrelevant scene details as if they are image noise (e.g. surface reflectance textures). The characteristics of noise depend on its source, as does the operator which best reduces its effects.
Many image processing packages contain operators to artificially add noise to an image. Deliberately corrupting an image with noise allows us to test the resistance of an image processing operator to noise and assess the performance of various noise filters.

How It Works

Noise can generally be grouped into two classes:

independent noise.
noise which is dependent on the image data.

Image independent noise can often be described by an additive noise model, where the recorded image f(i,j) is the sum of the true image s(i,j) and the noise n(i,j):

The noise n(i,j) is often zero-mean and described by its variance . The impact of the noise on the image is often described by the signal to noise ratio (SNR), which is given by

where and are the variances of the true image and the recorded image, respectively.In many cases, additive noise is evenly distributed over the frequency domain (i.e. white noise), whereas an image contains mostly low frequency information. Hence, the noise is dominant for high frequencies and its effects can be reduced using some kind of lowpass filter. This can be done either with a frequency filter or with a spatial filter. (Often a spatial filter is preferable, as it is computationally less expensive than a frequency filter.)
In the second case of data-dependent noise (e.g. arising when monochromatic radiation is scattered from a surface whose roughness is of the order of a wavelength, causing wave interference which results in image speckle), it is possible to model noise with a multiplicative, or non-linear, model. These models are mathematically more complicated; hence, if possible, the noise is assumed to be data independent.
Detector Noise
One kind of noise which occurs in all recorded images to a certain extent is detector noise. This kind of noise is due to the discrete nature of radiation, i.e. the fact that each imaging system is recording an image by counting photons. Allowing some assumptions (which are valid for many applications) this noise can be modeled with an independent, additive model, where the noise n(i,j) has a zero-mean Gaussian distribution described by its standard deviation (), or variance. (The 1-D Gaussian distribution has the form shown in Figure 1.) This means that each pixel in the noisy image is the sum of the true pixel value and a random, Gaussian distributed noise value.

Figure 1 1-D Gaussian distribution with mean 0 and standard deviation 1

Salt and Pepper Noise
Another common form of noise is data drop-out noise (commonly referred to as intensity spikes, speckle or salt and pepper noise). Here, the noise is caused by errors in the data transmission. The corrupted pixels are either set to the maximum value (which looks like snow in the image) or have single bits flipped over. In some cases, single pixels are set alternatively to zero or to the maximum value, giving the image a `salt and pepper' like appearance. Unaffected pixels always remain unchanged. The noise is usually quantified by the percentage of pixels which are corrupted.

Guidelines for Use

In this section we will show some examples of images corrupted with different kinds of noise and give a short overview of which noise reduction operators are most appropriate. A fuller discussion of the effects of the operators is given in the corresponding worksheets.
Gaussian Noise
We will begin by considering additive noise with a Gaussian distribution. If we add Gaussian noise with values of 8, we obtain the image

Increasing yields

and

for =13 and 20. Compare these images to the original

Gaussian noise can be reduced using a spatial filter. However, it must be kept in mind that when smoothing an image, we reduce not only the noise, but also the fine-scaled image details because they also correspond to blocked high frequencies. The most effective basic spatial filtering techniques for noise removal include: mean filtering, median filtering and Gaussian smoothing. Crimmins Speckle Removal filter can also produce good noise removal. More sophisticated algorithms which utilize statistical properties of the image and/or noise fields exist for noise removal. For example, adaptive smoothing algorithms may be defined which adjust the filter response according to local variations in the statistical properties of the data.
Salt and Pepper Noise
In the following examples, images have been corrupted with various kinds and amounts of drop-out noise. In

pixels have been set to 0 or 255 with probability p=1%. In

pixel bits were flipped with p=3%, and in

5% of the pixels (whose locations are chosen at random) are set to the maximum value, producing the snowy appearance.
For this kind of noise, conventional lowpass filtering, e.g. mean filtering or Gaussian smoothing is relatively unsuccessful because the corrupted pixel value can vary significantly from the original and therefore the mean can be significantly different from the true value. A median filter removes drop-out noise more efficiently and at the same time preserves the edges and small details in the image better. Conservative smoothing can be used to obtain a result which preserves a great deal of high frequency detail, but is only effective at reducing low levels of noise.

Interactive Experimentation

You can interactively experiment with this operator by clicking here.

Exercises

The image
is a binary chessboard image with 2% of drop-out noise. Which operator yields the best results in removing the noise?
The image
is the same image corrupted with Gaussian noise with a variance of 180. Is the operator used in Exercise 1 still the most appropriate? Compare the best results obtained from both noisy images.
Compare the images achieved by median filter and mean filter filtering
with the result that you obtain by applying a frequency lowpass filter to the image. How does the mean filter relate to the frequency filter? Compare the computational costs of mean, median and frequency filtering.

References

R. Gonzales and R. Woods Digital Image Processing, Addison Wesley, 1992, pp 187 - 213.
A. Jain Fundamentals of Digital Image Processing, Prentice Hall, 1989, pp 244 - 253, 273 - 275.
E. Davies Machine Vision: Theory, Algorithms and Practicalities, Academic Press, 1990, pp 29 - 30, 40 - 47, 493.
B. Horn Robot Vision, MIT Press, 1986, Chap. 2.
A. Marion An Introduction to Image Processing, Chapman and Hall, 1991, Chap. 5.

Eclipse CDT winth MinGW-w64

2011-05-17T12:07:00.002-04:00

This tutorial discusses how you can use MinGW 64-bit and Eclipse to build an application. This tutorial is based on 64-bit MinGW (probably version 4.5--the version is not clear from the download page) and Eclipse Galieo (SR2 Build ID:2010 02 18-1602) and Eclipse Helios (SR1 for Windows 64 bit, eclipse-cpp-helios-SR1-win32-x86_64). The following parts of this tutorial assume that you already installed Eclipse and MinGW 64-bit at your preferred paths and will only discuss how you can change Eclipse settings to build and run your applications.

Get Compiler

The first task is to obtain a proper MinGW w64 compiler. Although our target platform is Windows 64-bit, the compiler may be a 32-bit application that performs cross-compilation for you. You can choose your preferred version from here. There are some significant different for personal and automated builds (as of Dec 2010). For example, the sezero build I used (mingw-w64-bin_x86_64-mingw_20101003_sezero) is 64-bit binary producing 64-bit application, while a binary from the automated build (mingw-w64-1.0-bin_i686-mingw_20101129) is 32-bit binary generating 64-bit application. Technically, the automated build performs cross-compilation, while the sezero build performs native compilation. As sezero build has a conventional directory structures and file names (same as MinGW 32-bit), I recommend using the sezero build. It will save you a lot of time and you will not encounter some naming troubles in later steps.

In summary, from the link provided above, it is best if you go to the 'Personal Builds' section and download the latest sezero build. This is probably the best way to use Windows 64-bit to generate 64-bit applications.

Change Compiler Settings (Galieo SR2)

Go to menu Project->Properties.
Go to node C/C++ Build->Environment.
Update the path variable according to your MinGW w64 installation. For example, change it to C:\MinGW_w64\bin.
Switch to topic C/C++ Build->Settings.
[update (Dec 27, 2010): some recent MinGW versions (native compilation) come with 'as', 'g++', and 'gcc' commands. This step may be unnecessary for your MinGW build. However, some versions (cross-compilation) still have this issue and this step is required. If you use sezero build, this step is probably unnecessary.]

There are four commands to update: GCC Assembler, GCC C++ Assembler, GCC C Compiler, and MinGW C++ Linker. Correct commands depends on the platform of MinGW w64 you choose. No worry. It is quite obvious to know what commands to use, as the command names are in the format [platform prefix]-[default command].exe. For example, we need to update the command 'as', 'g++', 'gcc', and 'g++' for GCC assembler, C++ compiler, C compiler and C++ linker, respectively. The correct commands may be 'x86_64-w64-mingw32-as', 'x86_64-w64-mingw32-g++', 'x86_64-w64-mingw32-gcc', and 'x86_64-w64-mingw32-g++', respectively.

Change Compiler Settings (Helios SR1)

Eclipse Helios is virtually blank regarding compiler configurations, but it seems to be compatible with various GCC toolchains (Mac, Solaris, Cygwin, MinGW, and Linux). Our first task is to choose a proper toolchain as follows.

Go to menu Project->Properties.
Go to node 'Tool Chain Editor.' (The spelling of toolchain in Eclipse is not consistent. There are both 'tool chain' and 'toolchain.')
Set the current toolchain to 'MinGW GCC.'
Set the current builder to 'CDT Internal Builder.' You are free to use 'GNU Make Builder' if you prefer.
Go to node 'Settings.'
Change the path of compiler/assembler commands. For example, highlight 'GCC C++ Compiler' and change the command to 'C:\MinGW_64bit\bin\g++' if you save MinGW at C:\MinGW_64bit.

There is no path variable any more, but there is a new node called 'Discovery Options' inside 'C/C++ Build.' If we check 'Automate discovery paths and symbols,' most path settings are not necessary during program compilation.

If you employ OpenMP, you might want to see more detail at this site. Basically, you have to change the miscellaneous flag of GCC C++ Compiler and MinGW C++ Linker to include -fopenmp. Remember, however, that we have to change run-time settings, as OpenMP requires additional run-time libraries.

Change Default Include Folders

(This step is required for Galieo, but not for Helios. If you use Helios and choose 'Automate discovery paths and symbols' in 'C/C++ Build,' the defualt include folders should be correct right of the beginning.)

It is quite painful in this part, as Eclipse uses the C:/mingw by default. If you have multiple versions of MinGW, you have to change them. Fortunately, (almost) all include files are all the same among versions. Therefore, if we add header files to the default MinGW installation path, things should work across versions. These are, however, the include paths for the Eclipse editor. This means that Eclipse source-code editor can parse and show some hints if we add header files to the default 32-bit MinGW path, even though we are going to use 64-bit MinGW to perform actual program compilation. Therefore, for actual compilation, we need true addendum to an include folder that a compiler uses. See an example below.

Example: add OpenGL header files to Eclipse for actual compilation.
If we want to add header files to a 'global' include folder, such as GL, the include folder that will make things work has a platform prefix, say 'x86_64-w64-mingw32\include'. This is the case when we call gcc with the same prefix from a bin directory, such as 'x86_64-w64-mingw32-gcc.exe'. Addition of header files in other directories has no effect in actual compilation.

Change Run-Time Settings

At this step, you can build your 64-bit application, but you probably see that you cannot run it, even within the Eclipse environment itself. Your program might just be terminated without any reported error message. To deal with the problem, you also need to change run-time settings as follows.

Go to menu 'Run->Run Configurations...'
Go to tab 'Environment'.
Create a environment variable by using the 'New' button.
In a new popup window, set 'Name' to PATH and 'Value' to $PATH;C:\MinGW_64bit\bin, provided that C:\MinGW_64bit is the installation folder for your 64-bit MinGW. Note: if you have more paths to include, separate them with a semi-colon.

Alternatively, you can set Windows environment path variable to include the MinGW path. Nonetheless, if you have both 32-bit and 64-bit MinGW in the paths, some DLL names may cause DLL conflict and you may get 32-bit library instead of 64-bit library when you call your program. If your machine, however, has only 64-bit MinGW, using the Windows path variable is probably the most convenient way because you will have no need to create a path variable in Eclipse run-time settings for this purpose again. Nevertheless, dealing with Eclipse run-time settings does not need admin previlage to execute and it is always a viable option.

Because setting the Eclipse environment variable does not change any path variable outside Eclipse, we cannot run the application by double clicking on it or calling at command prompt, unless path variable for the executable session is set. To temporarily change Windows path variable, a command 'set path=%path$;C:\MinGW_64bit\bin' may be used [ref:http://vlaurie.com/computers2/Articles/environment.htm]. Again, separate library paths with a semi-colon if you have multiple library paths to add. This effectively appends the MinGW path to the existing path variable, specifically for the command prompt session. Therefore, it may be a bit awkward if we want to call an executable file from Windows Explorer, as a batch file may need to be created.

OpenMP Note: for sezero's MinGW build, you may need to unpack pthreads-w64.zip into the root of your MinGW folder (C:\MinGW_64bit) so that required OpenMP run-time libraries are available in a proper place.

Tips: some error messages from Windows may not show up in Eclipse when we run or debug our programs within Eclipse environment. Try using a command prompt (cmd.exe) and you may see more informative error messages.

Optional: Using MSYS to check if the compiled application is 64-bit

There are at least two ways to check if an application is 64-bit or 32-bit. The easiest way is to run it and see its process name in the Windows Task Manager. If the process name has a suffix *32, it is 32-bit. If there is no such suffix, it is 64-bit. There is another way. It is less convenient in my opinion, but you can probably use it to check your application programmatically without running it at all. This is possible if you use MSYS as discussed below.

Copy the executable file to a place where MSYS environment can reach. This is probably your home folder in C:\msys.
Enter 'file my_executable.exe'. For MSYS 1.0.11 32 bits (I ran it on 64-bit Windows 7), a 64-bit executable will get a message 'my_executable.exe: PE executable for MS Windows'. There is nothing about 32-bit or 64-bit tags showing up. A 32-bit executable, however, will get a message 'my_executable.exe: PE executable for MS Windows (console) Intel 80386 32-bit'. Namely, a 32-bit executable gets a clear description about its platform, while a 64-bit executable does not get any definite description. This is analogous to what the Task Manager does.

For more recent version of MSYS, the file command gives PE32 for a 32-bit executable and PE32+ for a 64-bit executable.

Pinyo Taeprasartsit
(May, Dec 2010)

This document can be viewed at my blog and my Google docs. I welcome questions, comments, and suggestions. Please leave a message in my blog if you have any. Thank you.

VirtualBox: using Guest OS on physical partition

2011-05-11T16:27:00.000-04:00

Setting up VirtualBox to boot linux from the physical Drive

In case of windows operating system,

cd c:\Program Files\Oracle\VirtualBox\

VBoxManage internalcommands createrawvmdk -filename /path/to/file.vmdk -rawdisk \\.\PhysicalDrive?

- ? is the number of physical drive.

2011-04-06T18:55:00.001-04:00

Installation of Oracle 11g Release 1 (11.1.0.6.0) on RedHat EL 4, 5 and (Oracle) Enteprise Linux 4, 5

This paper (HOWTO) describes step-by-step installation of Oracle 11g R1 database software on RedHat Enterprise Linux 4 and 5 or Enteprise Linux 4 and 5 shipped by Oracle Corp. This article is useful for Centos Linux release 4 and 5. Note that Centos distribution is not certified by Oracle Corporation.
This article does not cover database creation process, and ASM Instance creation process.

This paper covers following steps:

Pre-Instalation Tasks

1. Create oracle User Account

Login as root and create te user oracle which belongs to dba group.

su -

# groupadd dba

# useradd -g dba oracle

2. Setting System parameters
Edit the /etc/sysctl.conf and add following lines:

kernel.shmall = 2097152

kernel.shmmax = 2147483648

kernel.shmmni = 4096

kernel.sem = 250 32000 100 128

fs.file-max = 6553600

net.ipv4.ip_local_port_range = 1024 65000

net.core.rmem_default = 4194304

net.core.rmem_max = 4194304

net.core.wmem_default = 262144

net.core.wmem_max = 262144

Note: You need reboot system or execute "sysctl -p" command to apply above settings.

For RedHat (OEL, Centos, WBL) 4 version: Edit the /etc/pam.d/login file and add following line:

session required /lib/security/pam_limits.so

For RedHat (OEL, Centos) 5 version: Edit the /etc/pam.d/login file and add following line:

session required pam_limits.so

Edit the /etc/security/limits.conf file and add following lines:

oracle    soft  nproc  2047

oracle    hard  nproc  16384

oracle    soft  nofile  1024

oracle    hard  nofile  65536

3. Creating oracle directories

# mkdir /opt/oracle

# mkdir /opt/oracle/111

# chown -R oracle:dba /opt/oracle

4. Setting Oracle Enviroment
Edit the /home/oracle/.bash_profile file and add following lines:

ORACLE_BASE=/opt/oracle

ORACLE_HOME=$ORACLE_BASE/111

ORACLE_SID=ORCL

LD_LIBRARY_PATH=$ORACLE_HOME/lib

PATH=$PATH:$ORACLE_HOME/bin

export ORACLE_BASE ORACLE_HOME ORACLE_SID LD_LIBRARY_PATH PATH

Save the .bash_profile and execute following commands for load new enviroment:

cd /home/oracle

. .bash_profile

Download & Install

1. Download and install required .rpm packages

Some additional packages are required for succesful instalation of Oracle software. To check wheter required packages are installed on your operating system use following command:

rpm -q binutils elfutils elfutils-libelf gcc gcc-c++ glibc glibc-common glibc-devel compat-libstdc++-33 cpp make compat-db sysstat libaio libaio-devel unixODBC unixODBC-devel|sort

If some package is not installed then install it from installation media or download it from following locations:
RedHat Enterprise Linux 4 - source packages only
RedHat Enterprise Linux 5 - source packages only
Centos Linux 4
Centos Linux 5

This is example how to build RPM package from source package (libaio-0.3.105-2.src.rpm). Note gcc, make and rpm-build (and dependent) packages must be already installed on your system.

# rpm -ivh libaio-0.3.105-2.src.rpm

# cd /usr/src/redhat/SPECS/

# rpmbuild --target i386 libaio.spec

# cd ../RPMS/i386/

# rpm -ivh libaio-0.3.105-2.i386.rpm libaio-devel-0.3.105-2.i386.rpm

Install the required packages using the rpm command:

rpm -ivh <package_name>.rpm

2. Download the Oracle 11g release 1 (11.1.0.6.0) software from Oracle website.
Extract the files using following command:

unzip linux_11gR1_database.zip

3. Start the Oracle software installation process.

Now the system is prepared for Oracle software installation. To start the installation process execute the following commands:

cd database

./runInstaller

Post-Instalation Tasks

1. (Optional) Auto Startup and Shutdown of Database and Listener
Login as root and modify /etc/oratab file and change last character to Y for apropriate database.

ORCL:/opt/oracle/111:Y

As root user create new file "oracle" (init script for startup and shutdown the database) in /etc/init.d/ directory with following content:

#!/bin/bash

#

# oracle Init file for starting and stopping

# Oracle Database. Script is valid for 10g and 11g versions.

#

# chkconfig: 35 80 30

# description: Oracle Database startup script

# Source function library.

. /etc/rc.d/init.d/functions

ORACLE_OWNER="oracle"

ORACLE_HOME="/opt/oracle/111"

case "$1" in

start)

echo -n $"Starting Oracle DB:"

su - $ORACLE_OWNER -c "$ORACLE_HOME/bin/dbstart $ORACLE_HOME"

echo "OK"

;;

stop)

echo -n $"Stopping Oracle DB:"

su - $ORACLE_OWNER -c "$ORACLE_HOME/bin/dbshut $ORACLE_HOME"

echo "OK"

;;

*)

echo $"Usage: $0 {start|stop}"

esac

Execute (as root) following commands (First script change the permissions, second script is configuring execution for specific runlevels):

chmod 750 /etc/init.d/oracle

chkconfig --add oracle --level 0356

2. (Optional) Auto Startup and Shutdown of Enterprise Manager Database Control
As root user create new file "oraemctl" (init script for startup and shutdown EM DB Console) in /etc/init.d/ directory with following content:

#!/bin/bash

#

# oraemctl Starting and stopping Oracle Enterprise Manager Database Control.

# Script is valid for 10g and 11g versions.

#

# chkconfig: 35 80 30

# description: Enterprise Manager DB Control startup script

# Source function library.

. /etc/rc.d/init.d/functions

ORACLE_OWNER="oracle"

ORACLE_HOME="/opt/oracle/111"

case "$1" in

start)

echo -n $"Starting Oracle EM DB Console:"

su - $ORACLE_OWNER -c "$ORACLE_HOME/bin/emctl start dbconsole"

echo "OK"

;;

stop)

echo -n $"Stopping Oracle EM DB Console:"

su - $ORACLE_OWNER -c "$ORACLE_HOME/bin/emctl stop dbconsole"

echo "OK"

;;

*)

echo $"Usage: $0 {start|stop}"

esac

Execute (as root) following commands (First script change the permissions, second script is configuring execution for specific runlevels):

chmod 750 /etc/init.d/oraemctl

chkconfig --add oraemctl --level 0356

3. (Optional) You may consider to use rlwrap for comfortable work with sqlplus and adrci utility. RPM package for RedHat compatible (x86) distribution you can download here.

su -

# rpm -ivh rlwrap-0.24-rh.i386.rpm

# exit

echo "alias sqlplus='rlwrap sqlplus'" >> /home/oracle/.bash_profile

echo "alias adrci='rlwrap adrci'" >> /home/oracle/.bash_profile

. /home/oracle/.bash_profile

Common Installation Errors

DISPLAY not set. Please set the DISPLAY and try again.
Solution: Execute "export DISPLAY=:0.0" when you perform installation on local machine or "export DISPLAY=:0.0 when you perform installation on remote machine connected over SSH". Don't forget to execute "xhost +" command on client machine.

error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory
Solution: Install libaio and libaio-devel packages. If packages already installed and error still occurs try execute "ldconfig" as root.

Check complete. The overall result of this check is: Failed <<<<
Solution: Install missing package or set check system parameters (See reason of failure).

Comments, suggestions, questions, errors (also grammatical :) )? Feel free to contact me.

Environment variables on Oracle 11g Release 2

2011-04-06T15:36:00.002-04:00

Setting up environment variables

$ vi .bashrc
# add ORACLE_HOME, ORACLE_BASE and ORACLE_SID
# example
export ORACLE_BASE=/db/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1
export ORACLE_SID=oracle_sid

Test

$ sqlplus /nolog
SQL> connect / as sysdba
SQL> startup
ORA-01078: failure in processing system parametersLRM-00109: could not open parameter file 'anywhere'

If you are facing the above error while startup of oracle, possible reasons might be the init{ORACLE_SID}.ora file not accessible by oracle user. To solve this problem, you can get your pfile at the location $ORACLE_BASE/admin/$ORACLE_SID/pfile/. A typical file name is init.ora.{NUMBER}. From that location, make a spfile by the following:

$ORACLE_BASE=/db/app/oracle/ and $ORACLE_SID=ora_sid
$sqlplus /nolog
SQL> connect / as sysdba
SQL> create spfile from pfile='/db/app/oracle/admin/ora_sid/pfile/init.ora.{NUMBER}
File created.
SQL> startup

Compare with or Compare to?

2011-02-21T17:30:00.000-05:00

reference: http://homepage.smc.edu/quizzes/cheney_joyce/comparewithcompare.html

To identify either the similarities or the differences between two things, use "compare to." To identify both the similarities and the differences, use "compare with." In comparing with something, one finds or discusses both things that are alike and things that are different.

[Test]
1. In order to decide which city to tour, we had to (compare them with, compare them to) each other.
2. (Compared to, Compared with) running, walking is good for people who have knee problems.
3. Andy compared his math teacher (with, to) his English teacher and pointed out what they had in common and what they did not.
4. When Geri compares her old boyfriend (to, with) her new boyfriend, she points out all the ways in which they are alike.

1. with
2. to
3. with
4. to

Getting the hash value in C++

2011-01-18T14:25:00.000-05:00

C++ standard provides classes that get the hash value of the string corresponding to the character sequence.

ref - http://cplusplus.com/reference/std/locale/collate/hash/

A hash for a string is a value that uniquely identifies the content of the string, so that two strings with the same hash value, would compare equal by collate::compare, and two strings with different hash values would compare not equal.

Thus, two strings can be easily compared for equality by simply comparing their hash values, which are of an integer type.
During its operation, the version of this function in the generic template simply calls the virtual protected member do_transform, which is the member function in charge of performing the actions described above.

[Example]

// collate::hash example
#include <iostream>
#include <locale>
using namespace std;

int main ()
{
  string myberry = "strawberry";
  string yourberry;

  locale loc;                 // the "C" locale

  const collate<char>& coll = use_facet<collate<char> >(loc);

  long myhash = coll.hash(myberry.data(),myberry.data()+myberry.length());

  cout << "Please, enter your favorite berry:";
  getline (cin,yourberry);

  long yourhash = coll.hash(yourberry.data(),yourberry.data()+yourberry.length());

  if (myhash == yourhash)
    cout << "Mine too!\n";
  else
    cout << "I prefer strawberries...\n";

  return 0;
}

Vi Set

2011-01-05T09:16:00.003-05:00

:set ai (autoindeant)
윗라인과 같이 자동으로 들려쓰기를 해 줍니다.

:set nu(number) or nonu(nonumber)

:set showmatch or noshowmatch

:set si
코딩 할때 if, for 같은 것을 입력 하고 다음 라인으로 이동시 자동으로 들여쓰기를해줍니다.
:set paste
set ai, set si 같은 옵션을 사용할 경우 붙여 넣기를 하면 계단현상이
발생함으로 붙여 넣기 할경우에 이 옵션을 켜주면 방지할 수 있음

:set ts=4 (tabstop)
[tab] 키를 입력 하였을때 이동하는 크기를 조정 합니다.

:set sw=4 (shiftwidth)
"set si" 했을 경우 들려쓰기 하는 깊이를 설정 합니다.

:set et (expandtab)
[tab] 키를 입력 하였을때 tab에 대당하는 space 만큼 이동 됩니다.
(Python 언어 코딩 할때 매우 편리 합니다.)

:set encoding=cp949 or utf-8
작업 하는 컴퓨터 또는 개발 언어에서 기본 인코딩 타입을 설정 할 수 있습니다.
:set t_ti= t_te=
터미널 환경에서 vi를 종료 할때, 편집 하던 화면이 그대로 남도록 함
BSD 에서는 기본값인데, Linux 에서는 화면이 지워집니다.
BSD 환경에 익숙한 사람은 여간 불편한게 아니랍니다. 이 옵션을 주시면
바로 해결 됩니다.

:set ruler
우측 하단에 라인 및 컬럼 위치 표시및 전체 문서의 위치를 %로 표시

:set ff=unix (dos, mac)
라인변경 문자를 변경합니다.
:set key=<password>, set key=
문서를 암호화 시키고, 암호를 풀수 있음

:set ic (ignorecase)
검색패턴 사용시 대소문자를 구별 하지 않음
:set wam
저장하지 않고 종료시에 경고메시지 출력
:set sm (showmatch)
가로를 닫을때 열기 괄호를 보여줌

[참고]
* 알고 있겠지만 모든 명령의 취소는 no를 앞에 붙여 주시면 됩니다.
   예) :set noai

* 항상 같은 설정이 되도록 하려면 UNIX는 홈디렉토리 아래에 .vimrc 에 넣어 주시구요
   windows 는 vim 설치 디렉토리에 _vimrc 파일에 넣어 주시면 됩니다.
   예) set ts=4
   set si
   set ai
   set sw=4
   set encoding=cp494

vi 편집 작업시
1) 화면 스크롤
   ^F : 한 화면 앞으로 스크롤
   ^B : 한 화면 뒤로 스크롤
   ^D : 반 화면 앞으로 스크롤
   ^U : 반 화면 뒤로 스크롤
   ^E : 한줄 앞으로 스크롤
   ^Y : 한줄 뒤로 스크롤
   H (shift+h) : 화면의 맨 윗줄로
   M (shift+m) : 화면의 중간 줄로
   L (shift+l): 화면의 맨 아랫줄로

2) 화면 나누기
   : vs --> 수직으로 나눔
   : sp --> 스평으로 나눔
   ^ww --> 화면 간의 이동

3) 글자 변경
   Ctrl + A --> 커서 위치의 숫자 증가
   Ctrl + A --> 커서 위치의 숫자 감소

4) 마크 이동
   m[a~z] --> 현재의 위치를 기록
   '[a~z] --> 기록한 위치로 이동
   '' --> 이동하기 전의 위치로 이동

5) 접기
   V 로 블럭 설정을 한후에 'zf' 하면 접힘
   'zo' 를 하면 다시 펴짐

6) 함수/변수명 자동 완성
   호출 하고자 하는 변수명이나 함수명의 앞글자만 쓰고서 ^p 를 입력 하면 자동 완성 됨

7) 잠시 쉘로 나가기
   ^z, 들어 올때는 fg