Setup a Dedicated Web Server using Linux Ubuntu Cloud and Ubuntu Enterprise

Installing a Firewall

sudo cp /usr/share/doc/shorewall-common/myfwconfig/one-interface/* /etc/shorewall/

Note: sudo - super user do


Now, open the “rules” file:

sudo nano /etc/shorewall/rules


etc - directory for maintain lots of files.

text editor in linux

1. nano

2. vi or vim

3. emacs

4. pico

5. gedit

6. bluefish

Add these lines above where it says “#LAST LINE”

HTTP/ACCEPT net $FW
SSH/ACCEPT net $FW


Adding Web Site to Web Server

sudo usermod -g www-data [YOUR USERNAME]
sudo chown -R www-data:www-data /var/www
sudo chmod -R 775 /var/www


Note

775 - is equal to rwx rwx -rx

r - read

w - write

x - execute


other permissions


400 r-------- files
444 r--r--r-- files (read only)
600 rw------- files (file invisile to all)
666 rw-rw-rw- files
700 rwx------ allow permission to programs and directories
750 rwxr-x--- allow permission to programs and directories
755 rwxr-xr-x allow permission to programs and directories
777 rwxrwxrwx allow permission to programs and directories

Note: 777 dangerouse to use as permission

Redhat and Cent OS Web Traffic Monitoring

Do the Following:

1. Go to Terminal and Login as super user.

Command : su (super user)

2. see display connection by using the command

netstat -netstat

3. Install tcptrack package via Terminal.

yum install tcptrack

Installing in Ubuntu

sudo apt-get install tcptrack


Installing in Open Suse

zypper install tcptrack or go to YaST -> Software Management -> Search the Package tcptrack and Install the Package.

4. Track Ethernet traffic

tcptrack -i eth0
tcptrack -i eth1

Show web traffic on port 80.

5. tcptrack -i eth1 port 80

My simple floating point arithmetic program via Assembly language using C language

#include stdio.h
#define p printf
#define s scanf

int main() {

float var1, var2, sum, diff, product, dividend;

p( "Enter two numbers : " );
s( "%f%f", &num1, &num2 );

/* Perform floating point */
__asm__ ( "fld %1;"
"fld %2;"
"fadd;"
"fstp %0;" : "=g" (sum) : "g" (num1), "g" (num2) ) ;

__asm__ ( "fld %2;"
"fld %1;"
"fsub;"
"fstp %0;" : "=g" (diff) : "g" (num1), "g" (num2) ) ;

__asm__ ( "fld %1;"
"fld %2;"
"fmul;"
"fstp %0;" : "=g" (product) : "g" (num1), "g" (num2) ) ;

__asm__ ( "fld %2;"
"fld %1;"
"fdiv;"
"fstp %0;" : "=g" (dividend) : "g" (num1), "g" (num2) ) ;

p( "%f + %f = %f\n", num1, num2, sum);
p( "%f - %f = %f\n", num1, num2, diff);
p( "%f * %f = %f\n", num1, num2, product);
p( "%f / %f = %f\n", num1, num2, dividend);

return 0 ;
}

My IF Else Loop Sample in COBOL Programming in LINUX ^_^

PROCEDURE Decimal
Begin.
PERFORM DecimalValue THRU DecimalValueExit
STOP RUN.
DecimalValue.
Statements
Statements
IF ErrorFound GO TO DecimalValueExit
END-IF
Statements
Statements
IF ErrorFound GO TO DecimalValueExit
END-IF
Statements
Statements
Statements
IF ErrorFound GO TO DecimalValueExit
END-IF
Statements
Statements
Statements
Statements
DecimalValueExit
EXIT.

My Sample ABAP Program ALV Grid Control

My Sample ABAP Program ALV Grid Control


create a screen 100 for call it and Element list of screen supploy OK and type Ok inthe output

Then activate modules STATUS_0100 and USER_COMMAND_0100 in the flow logic .

CALL SCREEN 100.

MODULE STATUS_0100 OUTPUT.
SET PF-STATUS 'MAIN'.
IF C_CUSTOM_CONTAINER IS INITIAL.

CREATE OBJECT C_CUSTOM_CONTAINER EXPORTING CONTAINER_NAME = C_CONTAINER

CREATE OBJECT ALV_GRID EXPORTING I_PARENT = C_CUSTOM_CONTAINER.

CALL METHOD ALV_GRID->SET_TABLE_FOR_FIRST_DISPLAY
EXPORTING
* I_BUFFER_ACTIVE =
* I_BYPASSING_BUFFER =
I_STRUCTURE_NAME = 'bin1'
* IS_VARIANT =
* I_SAVE =
* I_DEFAULT = 'X'
* IS_LAYOUT =
* IS_PRINT =
* IT_SPECIAL_GROUPS =
* IT_TOOLBAR_EXCLUDING =
CHANGING
IT_OUTTAB = TAB_DISPLAY
* IT_FIELDCATALOG =
* IT_SORT =
* IT_FILTER =
* EXCEPTIONS
* INVALID_PARAMETER_COMBINATION = 4
* PROGRAM_ERROR = 2
* others = 1
.
IF SY-SUBRC <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
* WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.

ENDIF.
ENDMODULE.
MODULE USER_COMMAND_0100 INPUT.
CASE OK_CODE.
WHEN 'EXIT'.
LEAVE PROGRAM.

ENDCASE.
END MODULE.

My Sample Embedded C++ program using EC++ compiler

#include
using namespace std;

extern "C" void exit(int);


void johnpaul(const char *msg, int n)
{
cout << msg << n << endl;
exit(1);
}

// The integer array class

class Shit{
private:
// array elements
int *arry;
// array size
int array_counter; public:
// construct a array
Array(int n) : array_counter(n) {
if (n > 0)
elements = new int[array_counter];
else
die("Bad Array size, dumbass try again!!!! ", array_counter);
}
int &operator [](int index_list) const {
// overloaded operator
if (index_list < 0 || index_list >= array_counter)
die("Bad Array index ", index_list);
return arry[index_list];
}
int size() { return array_counter; } // return the size of the array
};

main()
{
Array m(6);
for (int i=0; i a[i] = i;
for (int i=0; i cout << i << ". " << m[i] << endl;
}

How to create and run COBOL Program in Linux ^_^

1. Write a Hello World Cobol Program

Create the JohnPaulSample program using the Vim editor as shown below.

$ sudo gedit JohnPaulSample

Note:

Types of Editor in Linux

1. Gedit
2. Kedit
3. Emacs
4. Anjuta
5. Nano
6. Vim
7. JEdit (Open Source Java Code Editor)

My Sample Program in Cobol

IDENTIFICATION DIVISION.
PROGRAM-ID. JohnPaulSampleProgram.
PROCEDURE DIVISION.
DISPLAY 'Hello John Paul!'.
STOP RUN.

Note: Comment in Cobol starts with *.
2. Make sure Cobol Compiler is installed on your system

Make sure Cobol compiler is installed on your system as shown below.

$ whereis cobc
cobc: /usr/bin/cobc /usr/share/man/man1/cobc.1.gz


Note:

whereis - command in linux for looking faster for a specific path or directory of file or package.




$ which cobc
/usr/bin/cobc

Installing COBC compiler

If you don’t have cobol compiler, install it as shown below.

$ sudo apt-get install open-cobol

Note

sudo - super user do. (Admin privileges)



3. Compile the cobol program trought Terminal

Compile the JohnPaulSample which will create the JohnPaulSample executable.

$ cobc -free -x -o JohnPaulSample-exe JohnPaulSample

$ ls
JohnPaulSample JohnPaulSample-exe*

* -free – use free source format. Without this option cobol program requires certain format.
* -x – build executable program.
* -o FILE – place the output file into the specified FILE.

4. Execute the cobol Program

Execute by mentioning the program name.

$./JohnPaulSample-exe
Hello John Paul!