Programming tips for Students

Penetration testing with metasploit

2010-11-18T13:28:00.003+08:00

Here's a little convincing tip for students, if you have a little free time and interested about hacking, try to learn these things:
1. exploits
2. shellcode
3. linux
4. C language (socket programming and pointers)
5. buffer overflow
6.a little knowledge of assembly language
7. metasploit framework

Googling about these things is a good step. I am thanking for the developers of metasploit and the contributors. Hope I can contribute someday. Metasploit framework is a powerfull tool for exploit development and penetration testing. Metasploit is extendable and versatile that you can add your customized exploit and payload.

Shellcode

2010-11-17T09:55:00.002+08:00

First thing that pops in your mind when you here shellcode, is exploit.Not really but it is used in to complete the objective of exploit. First you will write shellcode in assembly language then include it in your exploit code. Shellcode are small piece of code in hexadecimal form. It is injected in exploited program to accomplish hacker's objective.The original term 'Shellcode' means to execute shell.

From programmer to Systems Administrator

2010-04-13T16:56:00.003+08:00

It's been a long time since my last post. Now I had a little change on my career because I am now a Systems Administrator since Mar 01 2010. First I thought it was easy, but large amount of analytical skills is required for daily work. I am now in a different department of the bank so I am having a hard time adjusting and getting to know the process and the business in Trust Department. Still doing some programming jobs but ver minimal. One of the best things I like for my new job, is, I sometimes go home early. The advantage of that is, I study Java when I got home because I don't want to lose my skills in programming. The other good thing is, I am handling a powerful but simple system a little similar to my previous development project. As a programmer, I want to add all my favorite features of the system I'm handling now to my development project. If only i already knew this features before, I may be better for my previous job.

Relevance of Business process in software development

2009-09-29T18:12:00.003+08:00

During college days, we are required to make a project in every subject, in programming subject we still need a documentation. My hatest part is writing about business background because I don't know what to write. When I start working as a programmer, first thing I did is to interview some accountants so I will know their process and how they do it in operation. I recorded the interview on my mp3 player then listened to it when I'm back at my desk (what a programmer knows about banking and corporate finance, bonds, shares, coupons etc???). With that, I have written a lot of descriptions, specification and technical documentation that helped understand the process, how they do their work even if it is beyond my expertise and helped me solved the problem. Having a business process study also contributes to the existing software (which is poorly documented by the maker) that I developed and made it easier for me whenever they want to add something or there changes in their business process.

Be Object oriented

2009-09-29T18:11:00.002+08:00

When I am just starting to be a programmer, the way how I code is very procedural. Because as a begginer, I thought procedural is the simplest way and you can solve problems even not being an object oriented type of coder. Until I start working in a bank where I met complicated problems and still code the procedural way. I applied the way I code in C language which is a procedural language to a language that can create GUI. Eventually, I decided to learn a new language as my new skill, C++, an object oriented programming language. As I am studying C++, the book explained the true meaning of OOP that changed my mind and convinced me to make my project in object oriented way. At first I don't know exactly what is the difference between procedural and OOP, well, procedural has limitations while in OOP, you can create your own. This explanation really changed my way how I code: To solve a complicated problem, simulate the process by creating objects. For example, a radio composed of different parts or objects. You need to code for speaker, capacitor, antenna, tuner etc. to build a radio. You can download a capacitor which could be coded by others and adopt its functions and put it to your radio project to make it work. You can make objects in OOP just like what we have in real world. This way helped me solved complicated problems and make my application perform faster.

Visual Basic 6 Classes

2009-06-24T00:24:00.006+08:00

Hello,
When I was new in VB 6, using Class looks alien to me and seems hard to do. But then I realized that making class is very very convenient for you even in the future projects. I started using classes this year. I suggest you to google about visual basic classes, buy a book, or search this PDF: Basic Introduction to classes written by Mike D Sutton of Edais. This is where I started and reading C++ book also adds knowledge about classes/class programming. Using Classes can reduce developing/coding time for future use or future projects. Using class also make your program easy to maintain. You can add class to your visual basic project by: in your visual basic 6.0 IDE menu bar(along with File, Edit etc..), click Project, then click Add Class Module. Note: Using Module is different from Class Module. If you want to program professionaly in VB 6, learn proper using of classes, this could be your first step and advancement.

Happy 1st Anniversary

2009-06-24T00:17:00.004+08:00

Hi, It's been a year since I started this blog. I felt sorry that I haven't post many of my solutions that I have done with my projects because of my hectic schedule as a programmer. But all of that is written and I'll post that eventually. Some of tips that I got regarding rare problems and solutions are in http://www.experts-exchange.com/. I thank all of the guys there and in http://www.vbforums.com/ where I shared some solutions for the first time. I encouraged new programmers to be a member of these forums or others and read, read, and read. You can also ask some professional programmers/developers, It will help you a lot. Shalom!

Run-Time error '-2147217887 (8004Je21)'

2009-03-09T16:16:00.003+08:00

Multiple-step OLE DB operation generated errors. i encountered this error when uploading data from excel file straight to mssql database using ADODB. this is my simple solution: in my insert statement, i commented columns one by one and test insert query one at a time. until i reached the numeric data which will be uploaded to a numeric column, this is where run-time occurs. now i checked the columns in table and noticed that size of column is only numeric(10,2), so that i tried to changed it to numeric(14,2). Then run the test and all works fine, simple problem is solved.

Retrieving fields in mysql using php

2009-02-13T09:22:00.008+08:00

I experienced this problem when im retrieving data in mysql database. It is my 1st time to use select statement in php. I've read in some tutorial in the net that, mysql_fetch_array() can retrieve your data from database. But now i used this --> @mysql_fetch_array(); and it worked. I am using php 5 and the newest mysql version. This is my code:

if the code below gives you some error, try my 2nd code

$result = mysql_query("SELECT * FROM customer WHERE c_id = '$id'");
if(!$result)
{
die(mysql_error());
}
while($row = mysql_fetch_array($result))
{
echo $row['c_id'];
echo $row['c_comment'];
echo $row['c_name'];
}

At the end, this is my 2nd code:

$result = mysql_query("SELECT * FROM customer WHERE c_id = '$id'");
if(!$result)
{
die(mysql_error());
}
while($row = @mysql_fetch_array($result))
{
echo $row['c_id'];
echo $row['c_comment'];
echo $row['c_name'];
}

Using left Join to change specific data

2008-10-29T00:11:00.004+08:00

I encountered this problem during work. I accidentally edited a column(acctType) without having a parameter for where condition to specify an item to edit. The result is, all items in interest_table have changed its acctType to 'rt'. Now, all i have to do is to match it with other table. First, i looked for the relationship of the table or something in common with other table. Then i saw transaction_table. In this case, i used a simple update statement with left join. In other acctType, i used the same statement, but changed only 'rt' to necessary acctType.

solution:
UPDATE interest_table SET int_acctType = 'rt' FROM interest_table LEFT JOIN transaction_table on tu_number = int_number where tu_acctType = 'rt'

Moral lesson for this story: don't forget to use WHERE if neccessary

draw the flow

2008-10-10T22:27:00.005+08:00

When i was in college, i hate to draw flowcharts. i don't even believe that i can use that. in our school, we have to make projects in every subject. in my documentation there's a part called program design. Every process in our program we have to make a flowchart. When i got a job in an international bank as programmer, i draw pages of flowcharts. Learn to draw flowcharts. But in drawing flowcharts, know first the logic of the program. This will serve as your map in developing programs. This will be your logic flow to achieve your task or algorithm.

how to split strings in textbox in vb

2008-09-18T18:35:00.008+08:00

i encountered this problem during my work. so this is the story:

our client bank is using a different system when uploading the data(accounts) we have extracted from our system. one main problem is the name field. our system uses one textfield for name but their system is using 2 fields for name(firstname and surname). then i used this work around to fit with their system:
1. this one initializes the variables

Dim i As Integer

Dim b As String, c As String, d As String

Dim str2() As String

2. split string in text1 and assign it to array and text2 is ready to use for first name

str2 = Split(Text1, " ", , vbTextCompare)

Text2.Text = str2(0)

3. this assign the length of the string array to i and zero-out text3

i = UBound(str2)

Text3 = ""

4. this routine separates string from spaces

For a = 1 To i

If str2(a) <> "" Then

str2(a) = str2(a)

Else

a = a - 1

End If

5. re-assign the new value of i for use with the next routine.(printing of final strings)

i = UBound(str2)

If i <>i = 1

Else

i = 2

End If

6. this is the last routine, assign the strings collected in textbox

For a = 1 To i

Text3 = Trim(Text3 & " " & str2(a))

hope you learned from this little stuff.

Visual Basic 6 and Crystal Reports 10

2008-08-04T12:00:00.005+08:00

I wrote this because I spend 2 weeks solving how to use Crystal 10 with VB because I thought passing parameter in Crystal 8 is the same with Crystal 10. Crystal has many new features but I still prefer using Crystal 8 for ease of use.
In this tutorial, add 1 form to your project, add 1 button and two textbox
1. First, go to Project>references: Add Crystal ActiveX Report Viewer Library 10.0 and Crystal Reports ActiveX Designer Run Time Library 10
2. go to Project>Components: then add Crystal ActiveX Report Viewer Library 10
3.add new form to your project then draw the Crystal ActiveX Report Viewer to the form.

4.add this code to the form2:
Private Sub Form2_Resize()
crview.Top = 0
crview.Left = 0
crview.Height = Me.ScaleHeight
crview.Width = Me.ScaleWidth
End Sub
this for the viewers flexibility

5. add this code and put this on top of all (Declarations):
dim appl as New CRAXDRT.Application
dim rep as new CRAXDRT.Report
6. declare these variables in button_click():
Dim name as String, Address as String, ReportFile as String

7. and assign these variables to textboxes also in button_click():
name = Text1.text
Address = Text2.text
ReportFile = App.path & "\report.rpt" 'assuming that you have already designed your report.

8.This is how you pass paramater to your report(also in button_click():
Set rep = appl.OpenReport(ReportFile)
rep.DiscardSavedData
rep.ParameterFields(1).ClearCurrentValueAndRange
rep.ParameterFields(1).AddCurrentValue(name)
rep.ParameterFields(2).ClearCurrentValueAndRange
rep.ParameterFields(2).AddCurrentValue(Address)
Form2.show 'this is the 2nd form with Crystal Viewer

9. Add this code to form 2 Load() event:
crview.ReportSource = rep
crview.EnableExportButton = True
crview.Refresh
crview.ViewReport

Hope this tutorial gives you a lot idea about using crystal reports 10 and be able to use this with MS SQL or access,etc..

Basic Database programming in VB 6

2008-06-23T15:33:00.005+08:00

I wrote a small tutorial for those who still use VB 6. Some people especially students or beginners think of an ADO controls when they heard of a database. But on my experience, a professional guy saw me using a data control and said it is not applicable and not efficient for larger business soft or application. Then he told me not to use a shortcut and made me do this:
First, put 3 textbox on the form and 1 button. then:
1. Add ActiveX Data Objects 2.0 (or later) as reference :
In VB 6 environment/IDE: go to Projects> references

2. Declare

dim cn as ADODB.Connection

dim rs as ADODB.Recordset

3. Create connection string

cn.ConnectionString = "Provider=Microsoft.Jet.Oledb.4.0;Data source= " & App.Path & "\db.mdb;Persist security info=False"
cn.Open

4. Open the table and query data you want to come out

rs.Open "SELECT * FROM table1 WHERE name = '" & Text1.Text & "'", cn, adOpenKeyset, adLockBatchOptimistic

5. Fill the fields with the date you queried from the database

Text2.Text = rs.Fields("Name")
Text3.Text = rs.Fields("age")

Note: I used MS access database in this tutorial

Know The Rules and Constraint

2008-06-23T10:35:00.003+08:00

To be a skillfull programmer, it is also very important to know the rules. How can you design or write programs efficiently if you don't know the rules? You can make applications fast and less debugging moments if you know the rules in what ever programming language you are using. While studying or reading a book or tutorial of programming, you can't remember all keywords but the rules are easy to remember.

Palindrome program in C

2008-06-20T11:41:00.003+08:00

I used Borland C compiler in this small program. This program is my answer during my test when applying for software engineering job.

#include
#include
/*Start*/
main()
{
char str1[20], str2[20];
clrscr();
printf("Input: "); scanf("%s",&str1);
strcpy(str2,str1);
printf("%s\n",strrev(str2));
if(strcmp(str1,str2)==0) {
printf("String is Palindrome");
}
else
printf("Not Palindrome");
getch();
return 0;
}
/*end*/

There are many styles and ways in making a palindrome, it's up to you how you think or how good you are. Good programmers can make this small code complicated and hard to understand.

Cyber Wars

2008-06-20T11:35:00.000+08:00

In the world today, China is known as one of the giants when it comes to Business(especially in the Philippines.). China today is also being known when it comes to electronics and technology. As a programmer, I also admire these guys when it comes to programming and hacking. Using technology as first in line defense of the country is very very important. Lately in the news, China is using Internet as surveilance medium(just like playing China in Command & Conquer Generals). There was an American Software Developer hired by their government to track down hackers getting in to the U.S.' servers. These guys are believed getting important documents, plans and softwares. The U.S. hired hacker tracked that the hackers are from China and later figured out that they pretend that they came from korean servers to divert and not to be tracked. American hacker put a bug in the router where Chinese hackers pass and the logs are emailed to American hacker to know how many times and what time they attack the U.S.'s servers.

Apply for Programming Job

2008-06-16T12:55:00.003+08:00

During my OJT in a toothpaste company, I applied for a software engineering job near my Dad's Office. The test is fun and here are some of the common test they might give you when applying for a SE/Programming Job. :
1. Make a Palindrome - for those who doesn't know, palindrome is a word that is spelled the same even reading it backwards. (example: "radar")

2. Input 10 string then after inputing all, print the words alphabetically

3. Search key - Input a string then input a search key(letter in a string inputed) then the program will count the number of search key inside a string inputed.

example:

String: "Stigmatized"

key: i

answer is: 2

I wrote these questions on my hand(summary) while taking up the test to study it at home because I experienced difficulties when taking up these questions and solving it on a paper. These should be a lesson for IT/Compsci students that you should practice a lot. You don't have to remember all those keywords and functions in a Programming Language but at least read and practice so it makes you familliar in all keywords, functions and techniques. I learned a lot from these experience and really helped me from coping up. The Laguage I used here is Java and C.

C Language

2008-06-12T12:50:00.004+08:00

C Language is the first programming language I've learned when I was in First Year College. At first I found the language very difficult. One very good thing that gave me a drive to study C all by myself is that, C language, as a General Purpose Programming Language, is being used to hack systems. Yes! hack as in intruding in someone's PC, Network or even servers or routers. A guy named Dennis Ritchie is the one who developed C Language(History). C Language is a procedural language which is very easy to learn. But I suggest that it is very very important that you have interest in learning these for you to be able to master the C programming Language. I Bet! this is Fun!

Welcome To Programming Students

2008-05-12T13:25:00.003+08:00

Greetings, welcome to my blog about programming. I am Gian Paolo Balaag, work as a programmer in a Bank and also works freelance in making webpages with dreamweaver,photoshop and php. I am Hoping to interconnect IT/comsci students, beginners in programming and people who are interested in programming. Feel free also to take a look at my simple site. Thank You