- Prison Code Breaker Diary -

will add NUnit to Visual Studio as an External Tools

Main Menu: Tools > External Tools

Click button 'Add':

Title: NUnit Test GUI
Command: C:\Program Files\NUnit\bin\net-2.0\nunit.exe
Arguments: $(TargetName)$(TargetExt)
Initial Directory: $(ProjectDir)\bin\Debug

Click button 'OK'.

Now you can create your assembly and test it with NUnit tool plugged into your VS.

As far as I know, NUnit is the best Unit Test for .NET, give it a try!
http://nunit.org/index.php?p=download

#include 

#define CreateFunction( FunctionName, Operator, Type ) \
  Type FunctionName( Type a, Type b ) \
  { \
   return a Operator b; \
  }

CreateFunction( Add, +, int )
CreateFunction( Sub, -, float )
CreateFunction( Mul, *, long )

using std::cout;
using std::endl;

int main( )
{

 cout << "CreateFunction(Add, +, int)"    << endl
   << "10 + 15 = "   << Add( 10, 15 )    << endl
   << "CreateFunction(Sub, -, float)"   << endl
   << "12.4 - 4.34 = " << Sub( 12.4, 4.34 )  << endl
   << "CreateFunction(Mul, *, long)"    << endl
   << "40 * 123 = "   << Mul( 40, 123 )   << endl;

 return 0;
}

The 3 lines

CreateFunction( Add, +, int )
CreateFunction( Sub, -, float )
CreateFunction( Mul, *, long )

will be expanded during compile time.

A well-known trick under GNU/C.

This site might be helpful to someone interesting in embedded programming:
+ http://www.embedded.com/books , including the books references

#!/bin/bash
#Valentin Heinitz, www.heinitz-it.de, 2008-11-13
#Reader for MS Windows 3.1 Ini-files
#Usage: inireader.sh
# e.g.: inireader.sh win.ini ERRORS DISABLE
# would return value "no" from the section of win.ini
#[ERRORS]
#DISABLE=no
INIFILE=$1
SECTION=$2
ITEM=$3
cat $INIFILE | sed -n /^\[$SECTION\]/,/^\[.*\]/p | grep "^[:space:]*$ITEM[:space:]*=" | sed s/.*=[:space:]*//

I got it from here.

Linux bash shell provides 2 types of test:
+ ( -ot ) : is other than
+ ( -nt ) : is newer than

#!/bin/sh

if [ "$file1" -nt "$file2" ]
then
    echo -e "$file1 is newer than $file2"
else
    echo -e "$file1 is older than $file2"
fi

I write this bash script to automate the process of creating Linux libraries in C/C++

#!/bin/bash

clear

echo -e "##########################################"
echo -e "#     LIBRARY AUTO-CREATOR by [JaPh]     #"
echo -e "#========================================#"
echo -e "Usage: `basename $0` lib_name type path   "
echo -e "Example: "
echo -e " + creating libraries from hello.c in current directory"
echo -e " `basename $0` hello C . "
echo -e " + creating libraries from bye.cpp to '/opt/lib' directory"
echo -e "   `basename $0` bye C++ /opt/lib"
echo -e "Feel free to contact, pete.houston.17187@gmail.com\n"

ARG=3

if [ "$#" -ne "$ARG" ]
then
 echo -e "[?] wrong input arguments!"
 exit
fi

libname=lib"$1"

if [ "$2" == "C" ]
then
 filename="$1.c"
 compiler="gcc"
elif [ "$2" == "C++" ]
then
 filename="$1.cpp"
 compiler="g++"
else
 echo -e "[?] unknown filetype"
 exit
fi

echo -e "< Static Library: $libname.a >"
command="$compiler -Wall -c $filename"
echo -e "\$ $command"
if [ !`$command` ]
then
 echo -e ".created: $1.o"
else
 echo -e ".[?] cannot create object $1.o"
 exit
fi

echo -e "\$ ar -cvq $libname.a $1.o"
ar -cvq $libname.a $1.o
echo -e ".created: $libname.a"
echo -e "< Static Library '$libname.a' created ! >"

rm -f $1.o
echo -e "< Shared Object Library: $libname.so.1.0 >"
command="$compiler -Wall -fPIC -c $1.c"
echo -e "\$ $command"
if [ !`$command` ]
then
 echo -e ".created: $1.o"
else
 echo -e ".[?] cannot create object $1.o"
 exit
fi

command="$compiler -shared -Wl,-soname,$libname.so.1 -o $libname.so.1.0 $1.o"
echo -e "\$ $command"
if [ !`$command` ]
then
 echo -e ".created: $libname.so.1.0"
else
 echo -e ".[?] cannot create shared object $libname.so.1.0"
 exit
fi

ln -sf $libname.so.1.0 $libname.so
ln -sf $libname.so.1.0 $libname.so.1

echo -e "< Shared Object Library '$libname.so.1.0' created ! >"

if [ "$3" != "." ]
then
 mv $libname.* "$3"
 echo -e "[!] All files moved to $3"
fi

STATIC LIBRARY (.a)

+ Compile

$ gcc -Wall -c *.c

+ Create library

$ ar -cvq libtest *.o

+ List files in library

$ ar -t libtest.a

+ Linking with library

$ gcc -o executable-name prog.c libtest.a
$ gcc -o executable-name prog.c -L/path/to/library-dir -ltest

Shared Object: DYNAMICALLY LINKED LIBRARY

+ Compile object

$ gcc -Wall -fPIC -c *.c

+ Create shared object

$ gcc -shared -Wl,-soname,libtest.so.1 -o libtest.so.1.0 -o *.o

+ Move library to destination

$ mv libtest.so.1.0 /path/to/lib-dir

+ Allow naming convention like -ltest

$ ln -sf /path/to/lib-dir/libtest.so.1.0 /path/to/lib-dir/libtest.so

+ Allow run-time binding to work

$ ln -sf /path/to/lib-dir/libtest.so.1.0 /path/to/lib-dir/libtest.so.1

+ Testing executable file dependencies

$ ldd executable-file

Reference: Yo-Linux

Original Discussion -> [Cviet]

Code Relax #3 [ by rox_rook ]

- Write a class that allows operator overloading as long as possible and no syntax error.
Example, the following expression must be evaluated:

+++++++++++++++++++++++++++++++x; // must be valid and evaluated

- Language in use: C++

Solution [ by me ]

#include <iostream>

using namespace std;

template< typename X >
class MyOperator {
    private:
        X value;
    public:
        MyOperator( X _value = 0 ) : value(_value) { };
       
        MyOperator& operator+() {
            ++value;
        }
        MyOperator& operator++() {
            ++value;
        }

        X getValue() const { return value; }
};

int main( )
{
    MyOperator<int> x(7);
    ++++++++++++++++++++++++++++++++++x;
    cout << x.getValue() << endl;
   
    MyOperator<double> j(1.4);
    +++++++++++++++j;
    cout << j.getValue() << endl;

    return 0;
}

Evaluation
- The keyword 'operator' in C++ can be use to make cool things. I just found out about this 'til today testing it.

Original Discussion: -> [Cviet]

Code Relax #2 [ by rox_rook  ]

Given a template to get sum below

template< typename T >
inline
T calculate_sum_of_element( const T* i, const T* e )
{
    T sum = T( ); // a zero value for any type
    while( i != e )
    {
        sum += *i;
        ++i;
    }

    return sum;
}

Try this on int and char array

#include <iostream>

using namespace std;

template< typename T >
inline
T calculate_sum_of_element( const T* i, const T* e )
{
    T sum = T( ); // a zero value for any type
    while( i != e )
    {
        sum += *i;
        ++i;
    }

    return sum;
}

int main( )
{
    int int_ary[ 3 ] = { 1, 2, 3 };
    cout << calculate_sum_of_element( int_ary, int_ary + 3 ) << endl;
    
    char char_ary[ 3 ] = { 'a', 'b', 'c' };
    cout << calculate_sum_of_element( char_ary, char_ary + 3 ) << endl;
    return 0;
}

The result for int is 6 as expected; however, for char it supposed to be 97 + 98 + 99 = 294, but the character '&' is printed out.

Requirement
+ Re-write the given template function to make char data type return an int value
+ Language in use: C++

Solution [ by author, rox_rook ]

#include <iostream>
#include <fstream>
#include <iostream>
#include <string>

using namespace std;

template< typename T >
class Trait;

template< >
class Trait< char >
{
public :
    typedef int SumType;
    static SumType zero( )
    {
        return 0;
    }
};

template< >
class Trait< short >
{
public :
    typedef short SumType;
    static SumType zero( )
    {
        return 0;
    }
};

template< >
class Trait< unsigned >
{
public :
    typedef unsigned SumType;
    static SumType zero( )
    {
        return 0;
    }
};

template< >
class Trait< double >
{
public :
    typedef double SumType;
    static SumType zero( )
    {
        return 0;
    }
};

template< >
class Trait< int >
{
public :
    typedef int SumType;
    static SumType zero( )
    {
        return 0;
    }
};

template< typename T >
inline
typename Trait< T >::SumType calculate_sum_of_element( const T* i, const T* e )
{
    typedef typename Trait< T >::SumType SumType; // create shortcut, less typo
    SumType sum = Trait< T >::zero( );
    while( i != e )
    {
        sum += *i;
        ++i;
    }

    return sum;
}

int main( )
{
    char char_ary[ 3 ] = { 'a', 'b', 'c' };
    cout << calculate_sum_of_element( char_ary, char_ary + 3 ) << endl;
    double d_ary[ 3 ] = { 1.1, 2.2 , 3.3 };
    cout << calculate_sum_of_element( d_ary , d_ary + 3 ) << endl;    
    int i_ary[ 3 ] = { 1, 2 , 3 };
    cout << calculate_sum_of_element( i_ary , i_ary + 3 ) << endl;      
}

Evaluation
- It's freaking unthinking of....lol

Original Topic Discussion => [Cviet]

Relax #1 [ by me ]

Given 3 functions:

int add( int _a, int _b ) { return _a + _b; }
int sub( int _a, int _b ) { return _a - _b; }
int mul( int _a, int _b ) { return _a * _b; }

Implement the following program:
+ Prompt user to input 1 of 4 strings: "add", "sub", "mul" or "end"; otherwise, start program again; "end" to exit.
+ Then, prompt user to input 2 numbers
+ Output result in this form

A [operator] B = [result]

Operator must be one of the following '+', '-' and '*', according to its own function, which means string "add" match add() function ....

Requirement
+ Must use function pointer
+ Call function according to its name, call add() if user prompt "add"....so on.
+ Language to use: C, C++

Demo output

> type 'add', 'sub', 'mul' or 'end': add
 a = 1
 b = 2
 1 + 2 = 3
> type 'add', 'sub', 'mul' or 'end': sub
 a = 6
 b = 4
 6 - 4 = 2
> type 'add', 'sub', 'mul' or 'end': mul
 a = 12
 b = 1
 12 * 1 = 12
> type 'add', 'sub', 'mul' or 'end': end

PROGRAM ENDED ! 

Solution #1 [ by me ]


Code in C as following:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_SIZE    1024

//
// #struct JFUNC
//
struct JFUNC {
    char *name;                 // function name
    int (*func)(int, int);      // pointer to function
    char sign;                  // sign of function, '+', '-', '*'
};

//
// #function        say()
// #purpose         format output with given params
//
void say( int (*func)(int,int), int _a, int _b, char _ )
{
    printf(" %d %c %d = %d\n", _a, _, _b, func( _a, _b ) );
}

//
// #function        input()
// #purpose         get input from user
//
void input( int *a, int *b ) {
    printf(" a = "); scanf("%d%*c", a);
    printf(" b = "); scanf("%d%*c", b);
}

//
// #function        add(),sub(),mul()
// #purpose         provide regular calculation
//
int add( int _a, int _b ) { return _a + _b; }
int sub( int _a, int _b ) { return _a - _b; }
int mul( int _a, int _b ) { return _a * _b; }
//int div( int _a, int _b ) { return _a / _b; }

/* ENTRY POINT */
int main( )
{
    // init array of 3 structs
    struct JFUNC calc[3] = {
        { "add", add, '+' },
        { "sub", sub, '-' },
        { "mul", mul, '*' }
    };
    int a, b; // input from user
    int idx; // index of struct JFUNC array
    char *key = (char *)malloc( MAX_SIZE * sizeof(char) ); // string to get from user
    do {
   
        printf("> type 'add', 'sub', 'mul' or 'end': " );
        // get input, exactly 4 bytes
        fgets( key, MAX_SIZE, stdin );     

        // iterate through array to get correct function
        for( idx = 0; idx < 3; ++idx ) {
            // if function name is matched
            if( strcmp(calc[idx].name, key) == 0 ) {
                // get input
                input( &a, &b );
                // output
                say( calc[idx].func, a, b, calc[idx].sign );
            }
        }
    // end program if "end" prompted
    } while ( strcmp(key, "end") != 0 );
   
    // free memory
    free( key );
   
    printf(" PROGRAM ENDED!\n");
    // program return
    return 0;
}

Code in C++ as following

#include <iostream>

using namespace std;

//
// #struct JFUNC
//
struct JFUNC {
    string name;                    // function name
    int (*func)(int, int);      // pointer to function
    char sign;                  // sign of function, '+', '-', '*'
};

//
// #function        say()
// #purpose         format output with given params
//
void say( int (*func)(int,int), int _a, int _b, char _ )
{
    cout << " " << _a << " " << _ << " " << _b << " = " << func( _a, _b ) << "\n";
}

//
// #function        input()
// #purpose         get input from user
//
void input( int *a, int *b ) {
    cout << " a = "; cin >> *a;
    cout << " b = "; cin >> *b;
}

//
// #function        add(),sub(),mul()
// #purpose         provide regular calculation
//
int add( int _a, int _b ) { return _a + _b; }
int sub( int _a, int _b ) { return _a - _b; }
int mul( int _a, int _b ) { return _a * _b; }
//int div( int _a, int _b ) { return _a / _b; }

/* ENTRY POINT */
int main( )
{
    // init array of 3 structs
    struct JFUNC calc[3] = {
        { "add", add, '+' },
        { "sub", sub, '-' },
        { "mul", mul, '*' }
    };
    int a, b; // input from user
    int idx; // index of struct JFUNC array
    string key; // string to get from user
    do {
   
        cout << "> type 'add', 'sub', 'mul' or 'end': ";
        // get input, exactly 4 bytes
        cin >> key;

        // iterate through array to get correct function
        for( idx = 0; idx < 3; ++idx ) {
            // if function name is matched
            if( calc[idx].name == key ) {
                // get input
                input( &a, &b );
                // output
                say( calc[idx].func, a, b, calc[idx].sign );
            }
        }
    // end program if "end" prompted
    } while ( key != "end" );
   

    cout << " PROGRAM ENDED!\n";
    // program return
    return 0;
}

Solution #2 [ by tauit_dnmd ]

/*
  UITs:UITstudent.com
  Coder:tauit_dnmd.
*/
#include<iostream>
#include<string>
using namespace std;
typedef int (*MyType)(int,int);

int  add( int _a, int _b ) { return _a + _b; }
int sub( int _a, int _b ) { return _a - _b; }
int mul( int _a, int _b ) { return _a * _b; }

int (*GetFunctionVerSion1(string s,char &oper))(int,int) 
{
        if(s=="add"){oper='+'; return &add;}
        if(s=="sub"){oper='-';return ⊂}
        if(s=="mul"){oper='*'; return &mul;}
}

MyType GetFunctionVerSion2(string s,char &oper)
{
        if(s=="add"){oper='+'; return &add;}
        if(s=="sub"){oper='-';return ⊂}
        if(s=="mul"){oper='*'; return &mul;}
}

int main()
{
    int (*uitstudent)(int,int)=NULL;//define 
    int a,b;
    string myoperator;//operator
    char UITs;
    do
    {
        do
        {
            cout<<"type 'add' 'sub' 'mul' or 'end':"; 
            cin>>myoperator;
            if(myoperator=="add"||myoperator=="sub"||myoperator=="mul"||myoperator=="end") break;
        }while(1);
        if(myoperator!="end")
        {
            uitstudent=GetFunctionVerSion1(myoperator,UITs);//Or uitstudent=GetFunctionVerSion2(myoperator,UITs);
            cout<<"a= ";cin>>a;
            cout<<"b= ";cin>>b;
            cout<<"a "<<UITs<<" b = "<<(*uitstudent)(a,b)<<endl;
        }
    }while(myoperator!="end");
    cout<<"UITs:PROGRAM END!"<<endl;
    return 0;
}  

Solution #3 [ by QuangHoang ]

#include <iostream>
#include <string>
#include <map>
using namespace std;

typedef int (*func)( int, int );

int add( int _a, int _b ) { return _a + _b; }
int sub( int _a, int _b ) { return _a - _b; }
int mul( int _a, int _b ) { return _a * _b; }

map <string, func> fmap;
map <string, func>::iterator it;

void initMap()
{
    fmap["add"] = add;
    fmap["sub"] = sub;
    fmap["mul"] = mul;
}

bool result(string oper)
{
    bool ok = false;
    for ( it=fmap.begin() ; it != fmap.end(); it++ )
        if ( oper == (*it).first ) ok = true;

    if ( !ok ) return false;
   

    int a, b;
    cout << "a = "; cin >> a;
    cout << "b = "; cin >> b;

    cout << a << " " << oper << " " << b << " = " << fmap[oper]( a,b ) << endl;
   
    cin.ignore();
    return true;
}

string label()
{
    string lbl;

    for ( it=fmap.begin() ; it != fmap.end(); it++ )
        lbl += "'" + (*it).first + "', ";

    return lbl;
}

int main()
{
    initMap();
    string oper;

    cout << "> type " << label() << "or 'end': ";
    do
    {
        getline(cin,oper);
        if (oper == "end") break;  

        if (!result(oper))
            cout << "> retype " << label() << "or 'end': ";
        else cout << "> type " << label() << "or 'end': ";

    } while (true);

    cout << "\nPROGRAM ENDED !";
    return 0;
}

Solution #4 [ by rox_rook ]

#include <iostream>
#include <map>
#include <string>


int add( int a, int b ) { return a + b; }
int sub( int a, int b ) { return a - b; }
int mul( int a, int b ) { return a * b; }
int end( int a, int b ) { return 0;     } // dummy func

typedef int( *FUNC )( int , int );

int main()
{
    std::map< std::string, std::pair< char, FUNC > > _func;

    _func[ "add" ] = std::make_pair< char, FUNC >( '+', add );
    _func[ "sub" ] = std::make_pair< char, FUNC >( '-', sub );
    _func[ "mul" ] = std::make_pair< char, FUNC >( '*', mul );
    _func[ "end" ] = std::make_pair< char, FUNC >( ' ', end );

    std::string user_repl;
    int a, b;

    do {
        std::cout << "> type 'add', 'sub', 'mul' or 'end' : ";
        std::cin >> user_repl;
        if( user_repl == "end" )
            break;
        std::cout << "> 'a' 'b' : ";
        std::cin >> a >> b;
        std::cout << a << _func[ user_repl ].first << b << "=" << _func[ user_repl ].second( a, b ) << "\n";
    }
    while( 1 );

    return 0;
}

Evaluation

- Solution #1: My approach follows the traditions of C, calling function by name through a structure, which is mentioned in C-faq under section 20.6 ( Read C-Faq 20.6 )
- Solution #2: It's kinda handy in matching strings.
- Solution #3: mapping, but not really satisfy requirements.
- Solution #4: mapping using value of pair template, it's short, clear and understandable. I think it's the best solution under C++.

libcurl - the multiprotocol file transfer library

libcurl is a free and easy-to-use client-side URL transfer library, supporting FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, LDAP, LDAPS, FILE, IMAP, SMTP, POP3 and RTSP. libcurl supports SSL certificates, HTTP POST, HTTP PUT, FTP uploading, HTTP form based upload, proxies, cookies, user+password authentication (Basic, Digest, NTLM, Negotiate, Kerberos4), file transfer resume, http proxy tunneling and more!

libcurl is highly portable, it builds and works identically on numerous platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HPUX, IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOs, Mac OS X, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS and more...

libcurl is free, thread-safe, IPv6 compatible, feature rich, well supported, fast, thoroughly documented and is already used by many known, big and successful companies and numerous applications.

Homepage: http://curl.haxx.se/libcurl/

First, download and install cURL library package.
Then, use the utility 'curl-config' to get the compile options need for cURL program

$ curl-config --cflags
$ curl-config --libs

This is a simple program that retrieve a web page:

#include <stdio.h>
#include <curl/curl.h>
int main()
{
 CURL *curl;
 CURLcode res;
 
 curl = curl_easy_init();
 if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "xjaphx.blogspot.com");
  res = curl_easy_perform(curl);
  
  curl_easy_cleanup(curl);
 }
 return 0;
}

Try to compile with this option:

$ gcc -o curl_simple curl_simple.c `curl-config --libs`
$ ./curl_simple

The header is needed in program `#include `, you can find its location by this

$ whereis curl
$ whereis curl.h

Probably, it will be /usr/bin/curl /usr/include/curl
While compile, you need to specify the linking library, that's why I set option `curl-config --libs`.
If you run this command alone

$ curl-config --libs
-lcurl

That's the result. Instead, you can compile like this

$ gcc -o curl_simple curl_simple.c -lcurl

Which gives the same result.

NateOn is the instant messenger created by SK Telecom, for Koreans.
However, it does supports Windows only as main platform.
I've just found some projects that provides a way to communicate with NateOn under Linux.

1. For Mac / Linux (Gnome users):
- JateOn, written in Java (Swing, SWT required): http://jateon.kfmes.com/viewforum.php?f=4
It's still being developed.
- NateOn plugin for Pidgin: http://nateon.haz3.com
I don't think it is under development anymore....

2. For Linux (KDE users): this is the best choice
- NateOn Linux (current version 1.0 beta): http://nateonweb.nate.com/download/messenger/linux/
It's best if you are using Fedora, Gentoo or Ubuntu because the installation package is done, just one click and run. Other distros might need to download source and compile.

3. Using WineHQ to emulate:
- Some notes on experiment can give you a hint. You might want to give it a try: http://appdb.winehq.org/objectManager.php?sClass=version&iId=7524&iTestingId=11299

If you know any other, please notice me!

I accidentally found it here: http://bytes.com/topic/c/answers/561589-print-1-100-without-loops-c-c

#include 
#include 

void (*f[2])(int);

void
printnum(int n)
{
        printf("%d\n", n);
        int i;
        i = ++n <= 100;
        (*f[i])(n);
}

void
done(int n)
{
        exit(0);
}

int
main(void)
{
        int n = 1;

        f[0] = &done;
        f[1] = &printnum;

        printnum(n);

        return 1;
}

This is an amazing download manager, which is an add-on of Firefox. Not saying it's the best, however, if you are using Linux and looking for a good download manager, DownThemAll owns !!!

Homepage: http://downthemall.net/
Download: https://addons.mozilla.org/en-US/firefox/addon/201

I gave it a try and now it becomes my favorite one.
It supports downloads from almost all common network protocols, can resume downloads (also depending on the servers' allowance), just one click and download, especially, it can be used to download from various hosting sites like: rapidshare.com, megaupload.com, ....

Compare to others, I think I love DTA the most !

It's possible. Yes, it is!

NOTE: this guide is for education purposes only, not promoting for illegal actions

Requirements:
1. Crossover Linux Professional 7.0: get it here: Download

2. Installation package for Ms Office 2007.

How-to:

1. From menu, choose CrossOver -> Install Windows Software. Pick Microsoft Office 2007, locate the setup.exe file, then install it as in Windows.

2. After all installation done, we need to crack it though.
a. Get this file: Proof.XML
b. Replace the old one located under:

/home/[YOUR_USER_NAME]/.cxoffice/MSOffice/drive_c/Program Files/Common Files/Microsoft Shared/OFFICE12/Office Setup Controller/Proof.en

c. From CrossOver menu -> Run a Windows Command, type: regedit
d. Find the key: HKLM\Software\Microsoft\Office\12.0\Registration\DigitalProductID, and delete it.
e. Close all CrossOver-related program.
d. Under main menu: Applications, you can see Windows Application menu, and enjoy !


Enjoy !

These functions are usually used when dealing with binary data: open, read, write, close, seek and binmode.

I've written this perl script to generate a random binary file:

#!/bin/perl -w

use strict;

use constant RANGE => 0xFF;

if( $#ARGV != 1 ) {
    print "Error: no argument input!\n";
    print "Usage: > perl $0 FILE_NAME MAX_BYTES\n";
    print "Example: > perl $0 data.bin 255\n";
    exit;
}

my $file = $ARGV[0];
my $max_bytes = $ARGV[1];

my $cnt = 0;

open FILE,">", $file or die $!;

while( $cnt < $max_bytes ) {
    print FILE chr(int(rand(RANGE)));
    ++$cnt;
}

close FILE;

print "Binary file '$file' ($max_bytes bytes) generated!\n";

binmode() is not in used, so how does it work? Because I generate random value in ASCII so I can easily convert it into its according character, then simply write into file. It does sound weird but it actually works! The case of using binmode() and just print the number, it doesn't write the binary as expected. I don't understand why ???? The next script is to read a binary file and print out the hex code of each character inside.

#!/bin/perl -w

use strict;

if( @ARGV != 2 ) {
    print
     "Error: wrong arguments input!\n",
 "Usage: > perl $0 FILE BYTES\n",
 "Example: > perl $0 data.bin 255\n";
    exit;
}

my $file = $ARGV[0];
my $bytes = $ARGV[1];

open FILE, "<", $file or die $!;
#binmode FILE;

my $cnt = 0;
while( $cnt < $bytes ) {
    read FILE, my $byte, 1;
    print  sprintf("%02X", ord($byte)). " ";
    ++$cnt;
}
close FILE;
print "\n";

I use read() to get each byte then re-format into hex then print().
I don't use binmode() but it still does work well.

So I think I just don't need binmode() even though it's a binary case.

It's really itchy to have menu list cover half of your screen, they're way too biggggg!!!
I've googled to find the solution but it's like impossible @@!
Finally, I got the answer. This is how-to make it better look for you.

Choose a theme to use in order to edit that theme, example, I use 'Is Ora Smooth'.
Then I locate to its settings at: /usr/share/themes/Is Ora Smooth/gtk-2.0/gtkrc
Run gEdit or any text editor under root permission to edit this file.

Add this option into the file:

gtk-icon-sizes = "panel-menu=16,16"

I'm not sure if you want to make it smaller but the size is often like 16, 24 or 32.
Choose the one that best fits for you.
Logout and apply that theme, you'll see how beautiful it is!