Extract pom.xml version number using Shell script - Scenario 1

Guys, in todays post we'll look into an example where we want to extract version number from pom.xml of a Maven based project. In other words, all we have to do is extract text between 2 strings from a file. Quite obviously we would use sed for that. But let's look into a scenario where you have to pipe sed to other unix commands.

FYI this will work universally on Linux/Unix/Mac OS X flavors.

Let's say I have a pom.xml file of a Maven based project and I want to display only the version number from it. As you may be aware, we define the version number within the <version> </version> tags.

For e.g. my pom.xml looks something like this :

Here we want to extract only the version number from the file. i.e in this case I only want to display 1.0-SNAPSHOT.

Did you notice that in our file we have two lines of the <version></version> tags. One for our main project version and the other is for the dependency version. Now if we use sed to extract text between the "version" words, it will give output like this below.

sed -n '/version/,/version/p' pom.xml

  <version>1.0-SNAPSHOT</version>

  <packaging>jar</packaging>

  <name>testapp</name>

  <url>http://maven.apache.org</url>

  <properties>

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

  </properties>

  <dependencies>

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>3.8.1</version>

So let's display only the topmost line with head -1. That should help narrow down our output.

sed -n '/version/,/version/p' pom.xml | head -1

  <version>1.0-SNAPSHOT</version>

Now all we need is to extract the version number. Let's cut the output characters as follows :

sed -n '/version/,/version/p' pom.xml | head -1 | cut -c 12-23

1.0-SNAPSHOT

Cheers guys! That's what we wanted right? Now we could perhaps develop a script around this. Maybe have a variable which stores this version number. Perhaps we could use this variable for some conditional checks. Something like this :

#!/bin/bash

# Program to extract version number from the pom.xml

i=`sed -n '/version/,/version/p' /Users/ironcladzone/workspace/MavenTest/testapp/pom.xml | head -1 | cut -c 12-23`

echo $i

if [ $i = "1.0-SNAPSHOT" ]; then

echo "Version 1.0 Development copy. Team A is working on it."

else

echo "That's not a Version 1.0 Dev copy"

fi

Output :

./ExtractVersionFromPom.sh

1.0-SNAPSHOT

Version 1.0 Development copy. Team A is working on it.

The possibilities are limitless! Until next time, ciao!

Play audio file from Terminal on Mac OS X without iTunes

Guys, am sure this post will definitely interest you - how to play an audio file from Terminal on Mac OS X without using iTunes. Well, we play it using the "afplay" command.

Well here's what you need to do in Terminal :

afplay -q 1 --leaks /Users/ironcladzone/Music/Bo\ Saris\ -\ She\'s\ On\ Fire\ \(Maya\ Jane\ Coles\ Remix\).mp3 -d -r 1

Playing file: /Users/ironcladzone/Music/Bo Saris - She's On Fire (Maya Jane Coles Remix).mp3

Playing format: AudioStreamBasicDescription:  2 ch,  44100 Hz, '.mp3' (0x00000000) 0 bits/channel, 0 bytes/packet, 1152 frames/packet, 0 bytes/frame

Buffer Byte Size: 20135, Num Packets to Read: 19

Enable rate-scaled playback (rate = 1.00) using Spectral algorithm

-q switch is to set the quality level. 0 is default for low quality. Set it 1 for high quality version.

-d switch is for debugging which shows you the technical details like frames/packet, buffer byte size etc.

-r is the rate / speed of playback. Default is 1. Try changing it to 2 or 3 for speedier playback ;)

Oh and by the way, in case if you didn't notice, I was playing the cool Maya Jane Coles remix of Bo Saris' "She's on Fire". Maya Jane Coles rocks :)

Print a triangle using * in a Bash script

Hello coders! Hows it going? Today we'll see a basic simple shell script to print a triangle using asterisk * only. Here's the code to do that :

#!/bin/bash

# Simple program to print a triangle using * of height 10

star="*"

for i in {1..10}

do

echo "$star";

star="$star *"

done

You see basically, all we are doing is append a * to itself recursively. Here we are using a basic for-loop to print a triangle of height 10. You can change the height as per your requirement, as needed.

Output :

*

* *

* * *

* * * *

* * * * *

* * * * * *

* * * * * * *

* * * * * * * *

* * * * * * * * *

* * * * * * * * * *

Cheers!

Identify exact port number used by a process or app on Mac OSX

Guys, if you ever wanted to find out the exact specific port number used by a process/application on Unix/Mac OSX/Linux, type the following in Terminal :

top | awk '{print $2, $7}'

The output would be something like :

COMMAND #PORTS

awk 12

top 22+

top 19

This will show only the specific Command and Port columns from the top command and will skip other details like Process ID, % CPU utilisation , Memory usage etc.

Alternatively if you wanted to just find the port number used by a specific application, say for e.g. TextEdit, you could use the following command :

top | awk '{print $2, $7}' | grep TextEdit

TextEdit 140+

TextEdit 140

TextEdit 140

Cheers guys!

Read file line by line and count no. of lines using Shell script

Guys, in today's post we'll see how to parse a file line by line and count the number of lines in it.

We will simply use redirection to read the file. Note that we will pass the filename as a runtime parameter to the script.

Alright here we go. Suppose I have a file TextFile1.txt with the following contents. I want to print the total number of lines in it.

ABCD

DEFG

GHI

JKL

MNO

PQR

STU

VWXYZ

Now, here's the script part.

#!/bin/bash

#Sript to count number of lines in a file

File=$1

count=0

while read LINE

do

let count++

echo "$count $LINE"

done < $File

echo -e "Total $count Lines read\n"

Here's the output :

1 ABCD

2 DEFG

3 GHI

4 JKL

5 MNO

6 PQR

7 STU

8 VWXYZ

Total 8 Lines read

Cheers it has correctly displayed the count of lines in the file. In case of any questions/doubts, kindly leave your comments.

Search for string in a file and print the line : Unix basics

Guys, lets look into a very basic topic today. Today we'll see how to search for a string in a file and print the line in Unix/Linux/Mac OS X

Suppose I have a file SedText.rtf with the following text :

1.Here is a cute little tutorial for

2.trying out different things using

3.the Stream Editor or Sed in Unix.

4.The author of this tutorial is

5.none other than IroncladWriter

6.himself. The tutorial aims to

7.teach folks and educate how

8.they could unlock the power

9.of Unix to the fullest. Am posting

10.this on the blog IronCladZone

11.The best blog on the whole of

12.internet, where you can learn

13.technical stuff as well enjoy 

14.entertaining tidbits like movies,

15.music, television, fashion, food,

16.shopping, travel, trends etc.

17.Just sit back, relax and

18.ENJOY THE RIDE :)

Now I want to search this file for the keyword "Unix" and print all the lines. All we have to do is use the grep statement. Check this out :

grep Unix SedText.rtf

3.the Stream Editor or Sed in Unix.\

9.of Unix to the fullest. Am posting\