Dev : FTP-ing In Windows Using Script

Have you ever using FTP in Windows? Commands are almost similar with Unix. You may have use Unix Shell script, but have you tried using Windows batch file to help you do the job, for example, getting some log files from a Unix Webserver, without the hassle of typing repeating ftp commands?

There are 2 method.

Method 1:
Create 2 files. 1 is a text file (ftp_cmd.txt) , another is a batch file (ftp_cmd.bat).

ftp_cmd.txt

FTPuserLogin FTPuserPassword cd /user/define/location mget userlogfile.log y bye

ftp_cmd.bat

@echo off ftp -s:ftp_cmd.txt serverhostname

Method 2:
Create 1 batch file (ftp_cmd.bat).

ftp_cmd.bat

@echo off echo FTPuserLogin> ftp_cmd.txt echo FTPuserPassword>> ftp_cmd.txt echo cd /user/define/location>> ftp_cmd.txt echo mget userlogfile.log>> ftp_cmd.txt echo y>> ftp_cmd.txt echo bye>> ftp_cmd.txt ftp -s:ftp_cmd.txt serverhostname del ftp_cmd.txt

Please take note that the batch file cannot be named as ftp.bat. This will cause confusion between your batch file and ftp command and it will keep on displaying a loop. Every details must not end with a white space.

Dev : Adding New User

In Solaris, adding user is not as 'too' simple as in Linux.

When we use "useradd -d /home/unixuser unixuser" in Linux, we will be automatically create a user called unixuser and a new directory call /home/unixuser will be created.

However, in Solaris, "useradd -d /home/unixuser unixuser" will only create a user call unixuser, but no user home directory will be created. To make it easy, just add in an extra parameter called "-m", as in create home directory. So the better command for created user in Solaris should be "useradd -d /home/unixuser -m unixuser".

For more information on unix useradd, see here.

Dev : Increasing Heap Size Memory

Ever been in a situation where when you try to compile your projects, and all in a sudden, out of memory error occurs. Funny, I have sufficient memory on my pc, but what could have gone wrong? My task manager was showing low memory usage.

This probably could be caused by the heap size memory setting. Most setting, by default, is low. So how do we increase this so call memory? I have been using netBeans and Eclipse IDE for my development. So what I known of is in netBeans and Eclipse only.

Lets say we would like to increase the size to a minimum of 128Mb and maximum 256Mb,

In netBeans,

1. Go to projects tab.
2. Locate the project you wish to change the heap size, expand it.
3. Look for a folder call nbproject.
4. In nbproject, open the file called project.property.
5. Locate a line in the file called "runmain.jvmargs=".
6. Add in parameters. Make it "runmain.jvmargs= -J-Xms128m -J-Xmx256m".
7. Save the file and rebuild your classes.

In Eclipse,

1. Go to Package Explorer.
2. Locate the project you wish to change the heap size, right click it.
3. In the menu, find Run As > Run... .
4. A new windows will pop up. Go to the Arguments tab.
5. In VM Arguments text box, Add in parameters"-Xms128m -Xmx256m".
6. Click Apply and rebuild your classes.

Dev : Variables On Shell Script

A=100
B= $A+100
echo $B

What will the next line show?
a) 200 b)100100

If you answer b, then congratulation! But is there any way of making the answer a? Yes, there is. By using the keyword 'expr', the problem is solved. But how?

In the second line, instead of B=$A+100, change it to B=`expr $A + 100`. Remember the white spaces between the '$A', '+' and '100'. We can also use it for subtraction, comparison and other useful usage as well. You can either use the unix man expr, or click here for more information.

Dev : Installing Oracle 9i on Solaris 8

Whew... It's really a mess to install oracle in Unix machine. Lucky for me, I've found some steps online where it has reduce many white hair growing on my head.

It make me sweat when asking me to change the Solaris Kernel Parameters. After some troublesome findings, I finally manage to change the kernel parameters at /etc/system and manage to get the oracle 9i installed and database created. If not, you will always get oracle error complaining "Out Of Memory". Remember, it is the kernel parameters' fault. Not your RAM, not your SWAP (because I have increase my RAM from 512Mb to 1Gb and SWAP from 500Mb to 1.5 Gb :D ).

After installing and created a database, you need to create at least a user.
To create a user :

1. Login SQL*Plus with sqlplus "/ as sysdba".
2. In SQL*Plus, type sql > create user user_name identified by user_password;.
3. Grant some access for the user.
   sql > grant connect to user_name;
   sql > grant resource to user_name;
   sql > grant create any snapshot to user_name;

After that, to access oracle from other workstation, you should start the oracle process first.

1. In console, type cd /oracle/home/bin/.
2. To start the oracle process, in console, type ./lsnrctl start.
3. To start the database, in console, type ./dbstart.

And there you go! The very basic of oracle. :)

Dev : Swap for Solaris

How do we add extra swap space in Solaris version 5.x? For the ease of most users, follow the steps as below...

1. Log in console as root.
2. In console, type root: /usr > df -k to see the available space and the available swap by typing root: /usr > swap -l in console.
3. Locate a suitable location, create a file for swapping. Eg, to create an empty 1 Gb file call swapfile: root: /usr > mkfile 1g swapfile
4. Add the swapfile to the swap. Eg: root: /usr > swap -a /usr/swapfile (must use absolute path)
5. Edit the /etc/vfstab, add in a new line call /usr/swapfile - - swap - no - to enable the swap file at the next boot.
6. Check your swap again by by typing root: /usr > swap -l in console. You will find that there is a new swap available and you are ready to use it. :)

Dev : CVS vs VSS

Virtual Source Safe (a.k.a. VSS) and Concurrent Versions System (a.k.a. CVS), which one you prefer?

In general, VSS will lock a file for a user, and this will make sure no one will use the file until the current user checks it in. In the downside, when a user checked out the file for a long time, this means that other user have to wait for a long time too if they wanted to use it.

There are more comparisons we can get online, this is one of them.

ORA-00911: invalid character

ORA-00911: invalid character, I've been seeing this error message for 2 long, headache days. What is wrong with my SQL coding?

At first, I thought it was the values that I have inserted were wrong. After much checking, I decided to print out the whole query, copy it and put it into the Oracle SQL client to see what is fxxking wrong.

Test and test and test and retest. No! My query is totally correct to me, but it keep saying that I am wrong, even using Oracle SQL client! So my last resort for this is to remove each of the character in the query one by one. And there is it, the stupid ";" (semicolon) at the end of the query which cause all the misery!

Error: Object doesn't support this property or method

I was wondering for quite a while when I hit a javascript error. It stated "Error: Object doesn't support this property or method". The error was in this function, the line which has the word action:

function InsertRecord(){

var myForm = document.form1;

myForm.action="xxxxxxxxxxxx";
myForm.submit();
}

Lucky for me, my sifu, Steven, helped me out on this. My problem was actually a simple and silly error. What I done wrong was:

<button name="action" value="Attachment">

I have actually define one of my button in the form with the name of "action". After changing the name to a more meaningful one, it works once again. :-)

Signal Before You Turn

This morning while I was having my breakfast near a market area, out of a sudden, "bang~~crrraaanggg....". A motorcycle hit a car at the side! Luckily, the motocyclist and his pillion rider was not hurt bad. A few bruises thats all.

The point I am saying this is because nowadays, car signal had become useless to many drivers. They don't even bother to use it. Not until anything had happen. Some drivers are even smarter. They switch it on while turning, not before.

I felt sorry for the poor motorcyclist as I have experience the same thing before. For my case, a try to negotiate the driver to pay for my motorcycle maintenance, and if he would not do it, then I will file a police report on him. But later on, he tried to threaten me with my "Professional" sticker on my bike. He say if I were to report, I will have trouble with getting a valid licence. I quickly answer that the "P" was not mine as I have gotten my valid licence years ago. Only then, he agreed to pay me. Whew.... I was actually quite scared because it was 2 people against me. None of the busybodies who witness the incident stopped to help.