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 :)

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!

Start Stop Jenkins from Terminal on Mac OS X

Ola guys. I hope you came across my previous posts on setting up Ant and Maven with Jenkins. In today's post I'll show you how to start and stop Jenkins from Terminal on Mac OS X machine.

I assume you know how to shutdown Jenkins from console OR restart it from the URL field.

Alright so here we go.

For staring Jenkins from command line, type this in Terminal :

sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist

Give it a few seconds for Jenkins to startup and you can then see the console in the browser. If you still stay executing the startup command again you'll get the following message :

/Library/LaunchDaemons/org.jenkins-ci.plist: service already loaded

In the meantime you can double check if Jenkins has started by checking the process status in Terminal :

ps -ef | grep jenkins

For stopping Jenkins from the command line, type this in Terminal :

sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist

A rougher way to stop Jenkins is by killing the process ID of Jenkins that you found above with the ps -ef command.

Character Combinations using Shell Script

In today's post we'll look into a very simple entry level bash script in which we form all possible alphanumeric combinations using just 2 characters and save it in a file. You could tweak the program to suit your needs - e.g. all combinations of 6 or 7 or 8 characters or maybe include special characters as well. The file in which all these combinations are stored would be more like a dictionary.

#!/bin/bash

# Program to print all possible 2-character combinations

echo {a..z}{0..9} > /Users/ironcladzone/Documents/xyz.txt

echo {0..9}{a..z} >> /Users/ironcladzone/Documents/xyz.txt

Here's the output of xyz.txt :

a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 g0 g1 g2 g3 g4 g5 g6 g7 g8 g9 h0 h1 h2 h3 h4 h5 h6 h7 h8 h9 i0 i1 i2 i3 i4 i5 i6 i7 i8 i9 j0 j1 j2 j3 j4 j5 j6 j7 j8 j9 k0 k1 k2 k3 k4 k5 k6 k7 k8 k9 l0 l1 l2 l3 l4 l5 l6 l7 l8 l9 m0 m1 m2 m3 m4 m5 m6 m7 m8 m9 n0 n1 n2 n3 n4 n5 n6 n7 n8 n9 o0 o1 o2 o3 o4 o5 o6 o7 o8 o9 p0 p1 p2 p3 p4 p5 p6 p7 p8 p9 q0 q1 q2 q3 q4 q5 q6 q7 q8 q9 r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 s0 s1 s2 s3 s4 s5 s6 s7 s8 s9 t0 t1 t2 t3 t4 t5 t6 t7 t8 t9 u0 u1 u2 u3 u4 u5 u6 u7 u8 u9 v0 v1 v2 v3 v4 v5 v6 v7 v8 v9 w0 w1 w2 w3 w4 w5 w6 w7 w8 w9 x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 y0 y1 y2 y3 y4 y5 y6 y7 y8 y9 z0 z1 z2 z3 z4 z5 z6 z7 z8 z9
0a 0b 0c 0d 0e 0f 0g 0h 0i 0j 0k 0l 0m 0n 0o 0p 0q 0r 0s 0t 0u 0v 0w 0x 0y 0z 1a 1b 1c 1d 1e 1f 1g 1h 1i 1j 1k 1l 1m 1n 1o 1p 1q 1r 1s 1t 1u 1v 1w 1x 1y 1z 2a 2b 2c 2d 2e 2f 2g 2h 2i 2j 2k 2l 2m 2n 2o 2p 2q 2r 2s 2t 2u 2v 2w 2x 2y 2z 3a 3b 3c 3d 3e 3f 3g 3h 3i 3j 3k 3l 3m 3n 3o 3p 3q 3r 3s 3t 3u 3v 3w 3x 3y 3z 4a 4b 4c 4d 4e 4f 4g 4h 4i 4j 4k 4l 4m 4n 4o 4p 4q 4r 4s 4t 4u 4v 4w 4x 4y 4z 5a 5b 5c 5d 5e 5f 5g 5h 5i 5j 5k 5l 5m 5n 5o 5p 5q 5r 5s 5t 5u 5v 5w 5x 5y 5z 6a 6b 6c 6d 6e 6f 6g 6h 6i 6j 6k 6l 6m 6n 6o 6p 6q 6r 6s 6t 6u 6v 6w 6x 6y 6z 7a 7b 7c 7d 7e 7f 7g 7h 7i 7j 7k 7l 7m 7n 7o 7p 7q 7r 7s 7t 7u 7v 7w 7x 7y 7z 8a 8b 8c 8d 8e 8f 8g 8h 8i 8j 8k 8l 8m 8n 8o 8p 8q 8r 8s 8t 8u 8v 8w 8x 8y 8z 9a 9b 9c 9d 9e 9f 9g 9h 9i 9j 9k 9l 9m 9n 9o 9p 9q 9r 9s 9t 9u 9v 9w 9x 9y 9z

Area & Circumference of a circle - Shell script for Mac OS X

Guys in todays post let us look into a simple basic Mathematics problem. Let us automate the calculation of area and circumference of a circle, using a simple bash script. It's an easy script useful for learning some basic shell scripting.

Note : Value of pi used is a constant value rounded off to 3.142

#!/bin/bash

#program to calculate area and circumference of a circle

echo "=========================================="

echo "Area & Circumference of Circle Calculator"

echo "=========================================="

pi=3.142

echo "Please enter the radius of the circle : "

read radius

circumference=`expr "2*$pi*$radius"|bc`

echo "Circumference of circle : $circumference"

area=`expr "$pi*$radius*$radius"|bc`

echo "Area of circle : $area"

Output :

./AreaOfCircle.sh

==========================================

Area & Circumference of Circle Calculator

==========================================

Please enter the radius of the circle : 

5

Circumference of circle : 31.420

Area of circle : 78.550

Also do check out my previous post on Simple Interest Tool for additional scripting reference.

Script to check if a server / machine is up and running

Guys you might often come across some situations where you want to check if a server or machine is physically up and running. Quite obviously you would use the ping command to do so.

But in today's post let us write a simple bash script to automate this.

#!/bin/bash

#program to check if a server/machine is up and running

ipaddr=192.168.1.34

ping -c 4 $ipaddr >> /dev/null

if [[ $? -ne 0 ]]

then

echo "FAIL: Server seems to be down and not responding" 

else

echo "SUCCESS : Server is up and running"

fi

Note : $? is a special Unix variable to check if the previous command was executed successfully or not. It returns a numerical value - either 0 or 1. If the command was executed successfully, it returns 0, else if not, it returns 1.

In above script, simply replace the variable 'ipaddr' value to your server's ip address and check.

Also note that by redirecting the output of the ping command to /dev/null, we are suppressing and silencing the output i.e the ping o/p will not be shown on terminal. If you want to see the exact output of ping, remove the ">> /dev/null" part.

Output :

./PingServer.sh

SUCCESS : Server is up and running

Cheers!

Simple Interest Calculation : Shell Script for Mac OS X

Guys, today we'll look into a very basic simple shell script to calculate the Simple Interest. For this we need 3 essential details :

Principal Amount
Rate of Interest
Period i.e No. of years

Here's the bash script to calculate the Simple Interest.

#!/bin/bash

#program to calculate simple interest

echo "================================"

echo "Simple Interest Calculation Tool"

echo "================================"

echo "Enter principal amount : "

read principal

echo "Enter Rate of Interest : "

read roi;

echo "Enter No. of years : "

read years;

simple_interest=`expr "($principal*$years*$roi)/100"|bc`

echo "Simple Interest = $simple_interest"

Output :

./SimpleInterest.sh

================================

Simple Interest Calculation Tool

================================

Enter principal amount : 

5000

Enter Rate of Interest : 

9.5

Enter No. of years : 

5

Simple Interest = 2375

If you note, we have used the bc command to evaluate our expression i.e the Simple Interest formula. More on bc can be read here.

How to identify available shells on Mac OS X

Guys you may be aware that you can find your current shell in Mac OSX or any Unix machine by typing the following in Terminal.

echo $SHELL

/bin/bash

But to identify the available shells on Mac OS X type the following :

cat /etc/shells

# List of acceptable shells for chpass(1).

# Ftpd will not allow users to connect who are not using

# one of these shells.

/bin/bash

/bin/csh

/bin/ksh

/bin/sh

/bin/tcsh

/bin/zsh

Also, if you ant to change your default shell, type this :

chsh

Changing shell for ironcladzone.

Password for ironcladzone: 

Hope it helps. Cheers!

Mac OS X - Hidden Gems : Part 3

Guys in today's new gem, we'll see how to play the hidden game Tetris on Mac OS X which comes bundled by default for FREE. Didn't you even know that? I bet you didn't!

Allright! So to play Tetris on Terminal, do this :

• Open Terminal
• Type emacs
• Now hit the Esc button and immediately press x

• When you see the M-x prompt, just type tetris. Now simply relax and play a cool game of Tetris. How cool is that?

Upgrade Subversion on Mac OS X using Homebrew

Hi guys, in today's article we will see how to upgrade Subversion on Mac OS X using Homebrew. Subversion i.e SVN as you know is a popular centralised version controlling system.

First of all check in Terminal, the default pre-loaded version of Subversion that comes packaged with OS X.

svn --version

svn, version 1.7.20 (r1667490)

Now lets install Homebrew on the machine. For that just type the below command as mentioned on Homebrew's homepage. Btw for those who may be unaware, Homebrew is a free open source package management solution.

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Now it will begin the installation process and will change/update the owner and permissions of the following folders.

==> This script will install:

/usr/local/bin/brew

/usr/local/Library/...

/usr/local/share/man/man1/brew.1

==> The following directories will be made group writable:

/usr/local/.

/usr/local/bin

==> The following directories will have their owner set to ironcladzone:

/usr/local/.

/usr/local/bin

==> The following directories will have their group set to admin:

/usr/local/.

/usr/local/bin

Once Homebrew is installed, we need to install Subversion using it. First of all lets get some information about svn installation. Type this in terminal :

brew info subversion

subversion: stable 1.9.3 (bottled)

Version control system designed to be a better CVS

https://subversion.apache.org/

Not installed

From: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/subversion.rb

==> Dependencies

Build: pkg-config ✘, scons ✘

Required: sqlite ✘, openssl ✘

Optional: gpg-agent ✘

==> Options

--universal

Build a universal binary

--with-gpg-agent

Build with support for GPG Agent

--with-java

Build Java bindings

--with-perl

Build Perl bindings

--with-python

Build with python support

--with-ruby

Build Ruby bindings

==> Caveats

svntools have been installed to:

  /usr/local/opt/subversion/libexec

You see there are some dependencies that Brew will install along with Svn. Dependencies like sqlite, openssl etc. Proceed with the installation now and be patient for a while till it finishes.

brew install subversion

==> Installing dependencies for subversion: readline, sqlite, openssl

==> Installing subversion dependency: readline

==> Downloading https://homebrew.bintray.com/bottles/readline-6.3.8.el_capitan.bottle.tar.gz

######################################################################## 100.0%

==> Pouring readline-6.3.8.el_capitan.bottle.tar.gz

==> Caveats

This formula is keg-only, which means it was not symlinked into /usr/local.

.

.

.

==> Caveats

svntools have been installed to:

  /usr/local/opt/subversion/libexec

Bash completion has been installed to:

  /usr/local/etc/bash_completion.d

==> Summary

🍺  /usr/local/Cellar/subversion/1.9.3: 148 files, 11.1M

Just check which svn versions are installed on your machine. I mean the locations of svn.

which -a svn

/usr/local/bin/svn

/usr/bin/svn

Now after the installation is complete, if you check svn --version you will still see the older version of svn. Hey but it should be 1.9.3 the latest version right?

svn --version

svn, version 1.7.20 (r1667490)

To fix this we need to add a line to ~/.bash_profile

sudo vi ~/.bash_profile

export PATH="/usr/local/bin:$PATH"

Now type : source ~/.bash_profile

Check the svn version now and it will show the latest one.

svn --version

svn, version 1.9.3 (r1718519)

Cheers! You just upgraded Subversion on Mac OS X. Hope it helps guys!

Mac OS X - Hidden Gems : Part 2

Oh boy! yet another Mac OS X hidden gem that you probably weren't aware of.

Type this is Terminal to read Mrs Fields secret Cookies recipe.

open /usr/share/emacs/22.1/etc/COOKIES

Mac OS X - Hidden Gems : Part 1

Guys, presenting a mind blowing Mac OS X hidden gem that I just stumbled onto.

Type the following in Terminal to read some Apple supplied Jokes :)

open /usr/share/emacs/22.1/etc/JOKES

Get Mac OS X System Information from Terminal

Hii! Guys lets come back today on another topic related to Apple Mac OS X. Correct me if am wrong, the first thing you would after purchasing your new Macbook or iMac is double-check the system information right?

Typically you would click the Apple logo on top left -> About this Mac -> System Report. Well could you get the same information from command line? Yes you can!

Open terminal and just type the following :

system_profiler

It will list the system information in a matter of few seconds. You could also filter the command to get only specific information by piping to a grep command.

For eg :

system_profiler | grep Memory

system_profiler | grep Processor

system_profiler | grep CPU

Automate tasks using Expect scripts on Mac OS X

Expect is one of the hidden gems and quite esoteric scripting language for automating tasks on Mac OS X and on most unix flavors.

The idea behind expect is you can program the response to a programmed request string. It's much like a pre-programmed auto-complete feature, in which you have already told the system what the response should be, if it comes across a specific expected request.

Let's try out a basic simple script. In terminal create a new script file : vi expect_test.exp
Note the .exp extension, similar to .sh of bash scripts.

#!/usr/bin/expect

expect "hello"

send "Welcome to IroncladZone \n"

Now if you execute the script ./expect_test.exp and type the string "hello", it will automatically send the response "Welcome to IroncladZone".

Add suffix to strings in a file using Awk

Guys, in my previous post yesterday, we discussed how to add a prefix to strings in a file using Awk. Today lets work on the same example to add a suffix to the strings i.e append the strings with characters in the end.

We'll use the same set of phone numbers for formatting :

2127841212
3458922345
7713398403
6461228847

Let's add some characters to the these numbers in the end. How about something like " Extn : 7142". Here's the Awk code to do it below :

awk '{print $0 " Extn : 7142"}' Phones_unformatted.txt

Output :

2127841212 Extn : 7142

3458922345 Extn : 7142

7713398403 Extn : 7142

6461228847 Extn : 7142

Add a prefix to strings in a file using Awk

Suppose you have a file in Unix / Mac OS X which has phone numbers data. I mean lets say I have a text file named Phones_unformatted.txt which has some phone numbers as follows :

2127841212
3458922345
7713398403
6461228847

Now I want to format the phone numbers to have a prefix maybe like a country code +44- . something like :

+44-2127841212
+44-3458922345
+44-7713398403
+44-6461228847

If you observe I need to only append the phone number with some characters in the beginning. We can achieve the same using awk.

A simple awk code will do the trick as follows :

awk '{print "+44-" $0}' Phones_unformatted.txt

Output :

+44-2127841212

+44-3458922345

+44-7713398403

+44-6461228847

Viola!

How to setup Apache Ant on Mac OS X

Folks, presenting a quick tutorial on how to setup the build tool Apache Ant on a Mac OS X machine.

Download the relevant ant archive version from Apache Ant homepage. For this example we download the latest v1.9.6.
Store it locally at any location you like; maybe like /Users/Username/apache-ant-1.9.6

Now lets edit the .bash_profile to define the ANT_HOME environment variable.

sudo vim ~/.bash_profile

Add the following lines to it (make sure to replace with your own username in the path):

export ANT_HOME=/Users/IroncladZone/apache-ant-1.9.6/

export PATH=$PATH:$ANT_HOME/bin

Now source ~/.bash_profile and restart terminal.

Check the above settings by looking up the ant version in terminal :

ant -v

Apache Ant(TM) version 1.9.6 compiled on June 29 2015

Trying the default build file: build.xml

Buildfile: build.xml does not exist!

Build failed

This means your ant is ready to use for builds. Going forward all you have to do is pass the build.xml to trigger the build.

Folks, watch out for this space for more basic to intermediate to advanced tutorials coming up soon.

How to Set JAVA_HOME environment variable in Mac OS X

Check out a quick reference guide to set the JAVA_HOME environment variable in Mac OS X.

Open terminal and type the following :

• sudo vim ~/.bash_profile

• Enter your password

• Now in the vim editor, insert the following text :

export JAVA_HOME=(/usr/libexec/java_home)

• Save the .bash_profile from the vim editor using :wq

• Now type the following in terminal :

source ~/.bash_profile

Confirm your changes by typing the following in terminal :

echo $JAVA_HOME

You should see the value/path of JAVA_HOME environment variable you just set as above.

Transfer files between two servers using SCP

We can transfer files between 2 remote hosts using the scp command as follows :

scp Username@Server1:/path-to-file-to-be-copied/ Username@Server2:/destination-path-where-files-are-to-be-copied/

Note that you may have to enter the credentials manually after this to logon to both the hosts.

Eg :

scp user123@Unix_Host_1:/Users/user123/Documents/Textfile.txt user123@Unix_Host_2:/users/user123/Documents/

You may also use the -3 switch to transfer files from one machine to another through your local host.

Check out the following available switches on a Mac OS X machine :

usage: scp [-12346BCEpqrv] [-c cipher] [-F ssh_config] [-i identity_file]

           [-l limit] [-o ssh_option] [-P port] [-S program]

           [[user@]host1:]file1 ... [[user@]host2:]file2

Compare files contents in Mac OS X from command line using Comm

Comm is the command in Mac OS X if you want to compare the contents of two files through the command line.

The usage is as follows :

comm -switch file1 file2

where -switch can be any of the following :

-1 : This will not display the lines which are UNIQUELY present only in File1
-2 : This will not display the lines which are UNIQUELY present only in File2
-3 : This will not display the lines which are COMMON in both the files. i.e it will only display the unique lines from File1 and the File2

-i : This will basically display 3 columns. The 1st column will display lines which are UNIQUELY present only in File1. The 2nd column will display lines which are UNIQUELY present only in File2. And the 3rd column will display lines which are COMMON in both the files.

For eg:

we have taken two Text files for comparison, the contents of which are as follows :

TextFile1.txt

ABC
DEF
GHI
JKL
MNO
PQR
STU
VWX
YZ

TextFile2.txt

ABCD
DEFG
GHI
JKL
MNO
PQR
STU
VWXYZ
YZ

------ Usage 1 ------

comm -1 TextFile1.txt TextFile2.txt

ABCD

DEFG

GHI

JKL

MNO

PQR

STU

VWXYZ

YZ

------ Usage 2 ------

comm -2 TextFile1.txt TextFile2.txt

ABC

DEF

GHI

JKL

MNO

PQR

STU

VWX

YZ

------ Usage 3 ------

comm -3 TextFile1.txt TextFile2.txt

ABC

ABCD

DEF

DEFG

VWX

VWXYZ

------ Usage 4 ------

comm -i TextFile1.txt TextFile2.txt 

ABC

ABCD

DEF

DEFG

GHI

JKL

MNO

PQR

STU

VWX

VWXYZ