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 :)

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

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!

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

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 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

Stealth mode in Mac OS X

In Mac OS X, you can enable Stealth mode so that ping requests to your IP address are unreachable.

Go to System preferences -> Security & Privacy -> Firewall -> Firewall Options

Tick the Stealth mode options as shown below:

Now if you try to ping your Mac's IP address from another machine, you'll get the Request Timeout error with the stealth mode enabled.

Basic print examples in Unix using Sed

I was long thinking to write a short tutorial on covering some basic Sed examples for easy and quick reference. So here we are. In this short post I'll try to include some basic print examples with some variety... the more the merrier right?

The sample Testfile.txt we'll be using in this example is as below :

1.Here is a cute little tutorial for

2.trying out printing 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 :)

* Print only the first line of a file

sed -n '1p' Testfile.txt

OR you could also use the following:

sed q Testfile.txt

* Print only the last line of a file

sed -n '$p' Testfile.txt

* Print only the lines between 8th and 11th line of a file

sed -n '8,11p' Testfile.txt

* Print only those lines having the word "Unix" from the file

sed -n '/Unix/'p Testfile.txt

* Print only those lines after the word/pattern "shopping" to the end of the file. Note this will include the line containing the word "shopping" as well.

sed -n '/shopping/,$p' Testfile.txt

In my next post, I'll try to cover some advanced printing examples using Sed. Stay tuned fellas.

Hidden Screenshot Tricks on Mac OS X

Here's a quick guide to the keyboard shortcuts for taking screenshots on Mac OS X.

• For capturing the entire screen press Command+Shift+3.
• For capturing only the current active window press Command+Shift+4 and then the space bar and Return.
• For capturing a specific limited region from the screen press Command+Shift+4 and choose the area by dragging the crosshairs.

Now here'a a small compilation of the hidden tricks of screenshots :
-----------------------

By default the screenshots are saved as a .png file on the desktop. For changing the default save location do the following.
Open Terminal and type the following for example :

defaults write com.apple.screencapture location /Users/IronCladWriter/Pictures

Make sure to replace the location path as desired.
-----------------------
If you want to change the image type from default .png to say .jpg, simply type the following :

defaults write com.apple.screencapture type jpg

-----------------------
To apply the above changes type in Terminal :

killall SystemUIServer

-----------------------

Alternatively you could fire up the Grab application, as seen in Other Utilities

Lock Screen in Mac OS X

Here's a quick tip for the month of May - Q) How to lock screen of Mac OS X?

Answer : Control + Shift + Eject button

Correct me if am wrong, the Windows equivalent to lock screen is Windows button + L  right

Validate Fonts on Mac OS X

Occasionally or infact very rarely, fonts might get corrupt on Mac OS X. Mac OS X offers the option to validate the authenticity of fonts so that they are safe to use.

Open Fontbook

Click "All Fonts" from the Collection bar on left. Now select and highlight all the installed fonts using shift key (from top to bottom).

From the File menu -> choose Validate Fonts

You'll see the results of the output, something like below. This is a useful procedure to check the font authenticity, if you download & install some third party fonts from the Internet. Just an extra step of caution to make sure that nothing is corrupted. Hope it helps. Ciao.