Writing On The File Using Java

Hello Everybody today we are discuss about writing on the file by using java codes .........

Before we start writing on files:

.For Writing on the  file by java code you must know how to compile java program and little more.For this read our previous posts,  click here to see .
Now we start with coding

JAVA CODE

import java.io.*;

class write_on_file
{
public static void main (String args[])
{
File f=new File("happy.txt");
FileWriter fw=null;
try
{
fw= new FileWriter(f);
fw.write("***WELCOME TO BufferCode.in***Praveen Kumar***");
}
catch(IOException ex)
{
}
finally
{
try
{
fw.close();
}
catch(IOException exp)
{
}
}
}
}

You can use this code to handle your files using java code there you can use your file name which you wants to handle instead of happy.txt .

File f= new File("happy.txt"); is used to make object of file on which we have to write contents.

FileWriter fw=null; is used to make object of typewriter by which the writing operation have to perform.

fw.write("Anything you want to write"); is used to write on file

These are the code by which you can handle your file....

Ouput:

Thanks for Reading post and please wait for next post in which we discribe how to more about files .

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How to change windows pc password if we forget it

Change your password if you Forget it

Hello friends today we learn how to change your password if your account is locked/you forget your password.At that time most of the people think to reinstall the window

Some peoples give it's name creating a backdoor on your PC.Backdoor means a another way to enter in your PC. Now follow the following steps

How to Change your password if you Forget it

1. open system32( C:\\windows\\system32)
2. find sethc.exe
3. right click on sethc.exe-->properties--> security-->Edit-->allow all(check box)
4. now rename sethc.exe to kush.exe
5. now rename cmd.exe to sethc.exe(before that follow 1-3 steps for cmd.exe)
6. now press shift 5 times and command prompt will open .
7. type net users on cmd as in above image.
8. note the username
9. lock your pc
10. again press shift key 5 times
11. again cmd will open
12. type net users <username> * on cmd
13. enter password
14. re-enter password
15. password successfully changed

How it works???

Here sethc.exe file is use to on stickey keys ,when you press shift 5 times stickey keys pop up will on.

Now when you rename cmd.exe to sethc.exe and press shift 5 times ,cmd will open instead of stickey keys.
So on lock screen when you press shift 5 times you are able to open cmd even on lock screen.Now for what you are looking here just try it and do it.

That's the problem with windows/Microsoft they still work on keywords rather then id and programming codes.Here we can easily beat microsoft :)

NOTE:Our aim is to aware you about security issues not to harm anyone. We are not responsible if you missuse it. 

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How to use Pointers in C

                                               Pointers

Before you start: To learn how to compile a c programme click here or click here

Pointers are the difficult feature of C for beginners .Other languages have Pointers  but only few use them as frequently as C does.But Beginners should have to remember  that C’s clever use of  Pointers make C a excellent language .
Most of the Beginners feel difficulty in the Pointers terminology rather then the actual concepts of pointers.
Actually when a C programmer says that this variable is a pointer, what does it means ??
It seems hard to see how a variable can “point” to something/or in  a direction.
TO examine let us make a program

programming code for pointers

1.  We should include standard input/output header file (stdio.h).
2. must define a main function in program.
3. In this program we define two integer type variable ,one is a(simple holds a integer value) and another is *b (it is a integer pointer variable which  can holds the address of any variable).
4. Assign a value in a.
5. Assign the address of a in b.(as we know b is a variable of pointer type).
6. Print the address of a by &a and b (by both methods we can find the address )
7. Print the value of a by simple printf(“%d”,a) method and by printf(“%d”,*b) method(pointer’s method).

output:

Output of above proram

 

As we can see the output of previous program
by both the method address is same and also by both methods value is also same.
note that printing the value of  *(&a) give same result as printing the value of a.

To learn more in C click here

How to use Preprocessor in C

                          Preprocessor

Before you start: To learn how to compile a c program in C click here or click here

Preprocessor is a program to processes the input data and the produce output. In C preprocessor process is a source code before passes to the compiler . Various types of preprocessor are

#define, #ifdef , #endif , #undef , #else , #progma , #error , #line

the are various type of macro i.e  # defined keyword 

 

                           Compilation Stage :

1st is  Hand written Program

2nd is  C source code (xyz.c)

3rd is  Expanding Source code  (xyz . i)

4th is Object code (xyz.obj)

5th is Executable Code (xyz.exe)

Directives :

Preprocessor is several directives in C .It is a another set of Language in C.

1 Macro definition

2 File inclusion

3 Conditional Compilation

4 Miscellaneous directive

 

Macro Defination :

#define leng 50

the leng is the macro .Before the compilation process of source code ,the code is passes through  preprocessor which is check for macro. Macro expression replace a macro with specific chank of code

example:

#include<stdio.h>

#define LENG 50 

int main()

{

 int  t = 10;

printf  ("\n Sum " , t + LENG );

getch ();

return 0;

}

output :

sum 60

File Inclusion :

source code divide into multiple files and each file are contain multiple function that are interrelated to each other .In addition of multiple utility function and macros are used in multiple file i.e such function and macros are common use we can write .this concept of inclusion ,which is allows entire content of file to insert some source code.

#include "file" .h stands for header file

like

#include "mycode.c"

conditional compilation :

conditional  compilation are  #ifdef , #endif , #undef , #else , #ifndef

example:

#ifdef macro

  statement 1;

  statement 2;

  .

  .

  .

 statement n;

#endif

Miscellaneous Directive :

They are used for different purpose

#undef , #pragma ,#error ,#line

To learn more in C Click here

Most important Interrupt Handling in C programming

Interrupt Handling in C

Before you start: To learn how to compile a c programme in C click here  or click here

The communication goes from hardware toward the processor ,it referred to as interrupt (signal in C)Hardware device save the information interrupt in stack. If  this information is not fetch from stack immediately so then it lost. Interrupt handling is referred to signal handling.

 

Basic interrupt Handling in C

#include <stdio.h>

#include <signal.h>

void signalhand (int   sig)

{

 FILE *fp=fopen("C://signal.txt","a");

 fprintf(fp,"\n Signal received");

 fclose(fp);

}

int main()

{

signal (SIGINT, (void*) signalhand );

while(1)

{

printf("\n Infinite loop");

}

return 0;

}

if one process is processing another interrupt , then it deal with another interrupt when the current one process is complete  

In above C program we create a infinite loop ,which can terminate by pressing the CTRL + C key combination. When you pressing the  CTRL + C then keyboard informs the processor to interrupt generate in the program. the processor react with the interrupt the signal and running the or processing the another signal. we already register the signal handler i.e called interrupt generate by processor.

SIGINT function are used to register  a signal handler. SIGINT is a macro used to generate interrupt in the program.  when you pressing the CTRL+C  it generate a interrupt ,it forwarded by processor to the program and the it tapped by signal handler function and perform a certain action .

To learn more in C click here

How to implement Multithreading in C

                               Threads in c

Before you start: To learn how to compile a c programme in C click here or click here

Gone are the days when only single task could be executed in memory at any time.
Today in the environment of multitasking OSs like Linux and windows  permits execution of several task simultaneously. Hence ,these OSs are called Multitasking OSs.

#include"stdio.h"
#include"sys/types.h"

int main()
{

printf("hello \n");
fork();
printf("kushagra \n");
return 0;
}

To learn more in C click here

How to use C Programming Under Linux

                                 Process

Before you start: To learn how to compile a c programme in C click here or click here

Friends today we start linux first programme "process.c" by understanding some linux feature such as Process ID.
In Linux each running task is called 'process', and as we know today we live in the environment where modern OSs like Window ,mac and Linux perform several tasks simultaneously.Hence these OSs are called Multitasking OSs so in these OSs even a single programme can have more than one process .
Kernel assigns each process running in memory a unique ID to distinguish it from other running process known as PID or process ID.
We discuss later about Multiple Process or Multitasking . Today we start by making a program that print PID of a running process.

#include<stdio.h>

int main()

{

printf("Hello this is our Linux First Programme\n");

printf("PID of running process=%d \n",getpid());

return 0;

} 

Output:

root@bt:~/Desktop# gcc Process.c -o Process
root@bt:~/Desktop# ./Process
Hello this is our Linux First Programme
PID of running process=5181
root@bt:~/Desktop#

Above image is the output of previous program

 To learn more in C click here