Ronald Pringadi's Technical Notes

Bash Scripting Basics (Variable Assignment, If, Loop)

Posted on March 20, 2014 by ronaldpringadi

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#!/bin/bash
##################################################
# Benchmark the processing time when wkhtmltopdf
# converts an html file to a pdf file
##################################################

if [[ $1 = "" || $2 = "" || $3 = "" ]]; then
echo "Usage: `basename $0` sourceFile.html destinationFile.pdf iteartionRunTime"
else
_min=9999
_max=0
_total=0
_iteration=$3
for (( _i=1; _i<=$_iteration; _i++ ))
do
_start_time=`date +%s`
echo "running $_i"
~MYUSER/bin/benchmarkWkhtmltopdf.sh $1 $2 > /dev/null 2>&1
_end_time=`date +%s`
_processing_time=$((_end_time-_start_time))
if [ "$_processing_time" -lt "$_min" ]; then
_min=$_processing_time
fi
if [ "$_processing_time" -gt "$_max" ]; then
_max=$_processing_time
fi
_total=$(($_total+$_processing_time))
done
_processing_time_average=$(echo - | awk "{print $_total/$_iteration}")
echo "Processing time avg: $_processing_time_average min:$_min max:$_max total:$_total"
fi

Posted in Bash, Linux | Leave a comment

Compress and Extract Files in Linux

Posted on March 10, 2014 by ronaldpringadi

Extract:

.tar.bz2
To extract a tar (Tape ARchiver) file, type the following in the shell prompt:

1	tar xvjf yourFileName.tar.bz2

Which will untar it to the current directory. Depending on the file structure that being compressed, it might create sub-directories.
Parameters:
x – extract
v – verbose output (lists all files as they are extracted)
j – deal with bzipped file
f – read from a file, rather than a tape device

.tar.gz or .tgz

1 2	tar xvzf file.tar.gz tar xvzf file.tgz

Parameters:
-x, –extract, –get extract files from an archive
-v, –verbose verbosely list files processed
-z, –gzip, –gunzip, –ungzip filter the archive through gzip
-f, –file=ARCHIVE use archive file or device ARCHIVE

.bz2 file

1	tar jxf YOUR_FILE_NAME.bz2

.zip file

1	unzip YOUR_FILE_NAME.zip

Posted in Bash, Linux | Tagged linux bash | Leave a comment

Using VBA macro for Excel

Posted on January 22, 2014 by ronaldpringadi

Let’s start with something simple, assume that we have a big spread sheet and we want to highlight it based on a certain subject. For example expenses about car. For the sake of the example we’ll keep it short, but in real life you could be dealing with hundreds of rows.
Excel challange 1

We can see that cell B2 and B7 contains the word “car”, so how you do you highlight these cells using an excel formula? You can’t! The only way to do this is with a VBA macro. VBA macro is much more robust than excel formulas – in essence VBA is a programming for Excel.

So let’s start programming!

1. Enable the VBA development environment. In your Excel, press Alt + F11 . If that doesn’t work:

Go to File > Options > Customize > Ribbon
In the main tabs. Go to “Customize The Ribbon” > check “Developer”
Click on the “Visual Basic” icon.
A new window will open saying “Microsoft Visual Basic for Applications”

Double click on “Sheet 1”. Then at the top menu go to “Insert” > “Procedure”. Give it a meaningful name “HighlightCarExpenses”

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Public Sub HighlightCarExpenses()
Rem this is a comment
Dim emptyCounter, currentRow As Integer
Dim currentCell As Range
Dim currentCellValue As String

Rem Set initial value for the empty cell counter
emptyCounter = 0
currentRow = 1
currentCellValue = ""

Rem Scan al column B values
Rem Stop scanning if we see 3 empty cell in column B
Do While (emptyCounter < 3)
currentCellValue = ActiveSheet.Cells(currentRow, 2).Value
Debug.Print "Value at row " & currentRow & ": " & currentCellValue

If (currentCellValue = "") Then
emptyCounter = emptyCounter + 1
ElseIf InStr(1, currentCellValue, "car", 1) Then
Debug.Print "Car is found at row: " & currentRow
ActiveSheet.Cells(currentRow, 2).Interior.Color = RGB(256, 0, 0)

End If
currentRow = currentRow + 1
Loop
Debug.Print "last row" & currentRow

End Sub

Glossary

Comment: Part of the code (sentences) that will not be executed by the system. This can be a way for the user/programmer to put a note to her/himself
Debug: Trace a value(s) to find and remove mistake, or just to ensure program correctness.
Dim: A declaration for variable
Integer: A data type that is numerical. Example: 1, 2, 3, etc
String: A data type that is alpha-numerical. Example: “I have 2 dogs”, “Expenses are bad”, etc. Be aware that a string is always written within double quotes (“)

Posted in Visual Basic | Leave a comment

Remote copy using scp

Posted on January 15, 2014 by ronaldpringadi

Do you ever need to copy one file from one server to another? If you have ssh access to the remote server then you can do an scp command like so:

1	$ scp remoteUsername@remoteServername:remoteFile localFile

Posted in Linux, Operating System | Tagged linux | Leave a comment

Delete files older than X number of days in Linux

Posted on November 17, 2013 by ronaldpringadi

Say you backup your database daily and you need to delete the old backup files.
You can issue the command bellow which will erase any files within the specified directory that are older than 7 days.

1	$ find /your/target/directory* -mtime +7 -exec rm {} \;

Posted in Bash, Linux, Operating System | Leave a comment

DSQUERY

Posted on November 5, 2013 by ronaldpringadi

dsquery * “CN=Users,DC=myadserver,DC=com” -scope onelevel -attr objectguid proxyaddresses -limit 2000 >C:\myadserver.user.list.txt

Posted in LDAP and Active Directory | Leave a comment

Calling a mysql query from linux or dos command line

Posted on October 26, 2013 by ronaldpringadi

There are times when you want to call a mysql command from the bash or dos script then call this script in a scheduler (cron job).
The example below will show you how to do so.

1	mysql -uYOURUSERNAME -pYOURPASSWORD -DYOURDATABASE -e"CALL YOURSTOREDPROCEDURE('YOUR_SP_PARAMETER')"

Explanation:
-u is where you put your username, you can either put a space or no space at all after the -u (both works). As you can see I prefer not to put any space.
-p is where you put your password.
-D is your database name. That’s a capital D.
-e this is where your query will go. It needs to be quoted (“). If it’s calling a stored procedure or stored function, you’ll need to use the CALL keyword, otherwise if it’s just a simple query don use the CALL keyword.

Posted in Database, Linux, MySQL | Leave a comment

Remove all svn directory

Posted on October 20, 2013 by ronaldpringadi

Subversion (SVN) sometimes clutter our source directory by creating .svn folder in each folder or sub folder that we version control.

The easiest way to erase them is by using a bash command:

1	find . -name ".svn" -type d -exec rm -rf {} \;

Posted in Linux, Version Control | Leave a comment

Adding New VirtualHost in Apache2

Posted on October 16, 2012 by ronaldpringadi

On linux Ubuntu
1. If your apache has /etc/apache2/sites-available directory then just create a new file “dev.newwebsite.com.conf”
with the following content:

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<VirtualHost *:80>
ServerName dev.newwebsite.com
DocumentRoot "/var/www/www.newwebsite.com"

# Error handlers
ErrorDocument 500 /errordocs/500.html

<Directory "/var/www/www.newwebsite.com">
AllowOverride All
Options -Indexes FollowSymLinks
Allow from all
</Directory>
</VirtualHost>

2. Also copy the same file into /etc/apache2/sites-enabled

3. Restart your apache

1	$ /etc/init.d/apach2 restart

4. Edit your hosts file: /etc/hosts
add the following line to it
127.0.0.1 dev.newwebsite.com

5. Open your web browser and open http://dev.newwebsite.com

If you are a windows user and are using xampp then you need to alter the vhost configuration file.
The default xampp file is in
“\xampp\apache\conf\extra\httpd-vhosts”
Then restart your apache

Posted in Operating System, php, Ubuntu | Leave a comment

Memcache test connection script

Posted on October 15, 2012 by ronaldpringadi