Simple I/O with bash scripting

I/O is a based of computer work because this capacity make computer so power.
I/O is a device that handle input and output, both for keyboard, floppy, monitor screen, etc. 
beside echo, we can use printf command to print out with output standard, in screen or in file with specific format.

below this example:

#!/bin/bash
#pr1

url="elvin.enderson.blogspot.com";
number=32;

printf "Hi, use printf ala C\n\t\a in bash\n";
printf "My url %s\n %d decimal = %o octal\n" $url $number $number;
printf "%d decimal in float = %.2f\n" $number $number

and below is the result

[elvin@Testbed$]./pr1
Hi, use printf ala C
    in bash
My url  elvin.enderson.blogspot.com
32 decimal = 40 octal
32 decimal in float = 32.00

below it the table for the format control

Format control	information
%d	data integer format
%o	octal
%f	float atau decimal
%x	Hexadecimal

Input with read

after echo and printf for output process, now we will use command read.

this command very good to read or accept input from standard input

below is the example

#!/bin/bash
#rd1

echo -n "Your name :"
read name;

echo    "Hi $name,  How are you?";
echo    "message and reply :";
read 
echo    "said $name, $REPLY";

below is the result

[elvin@Testbed$]./rd1
Your name : elvin
Hi elvin, How are you?
message and reply :
i'm fine. thanks
said elvin, i'm fine. thanks