New website:

http://www.cs.indiana.edu/classes/a202

Problem for today: 

Using the language of your choice write a program that asks
the user for a name and current age (number of years) and writes
back a report saying how old that person will be a year from now.

Example:

start> Welcome to the program.
Type your name: .... (e.g., Larry Bird then hit enter)
Type your age (in years): ... (e.g., 56)
Well, Larry Bird, next year you will be 57!

Then the program ends. 

Time: 5 minutes

E-mail me the program 

Choices: perl, Python

a) Python

Log into silo. 

Then choose a place to write a program (a folder): ~/09101115

mkdir ~/09101115

cd ~/09101115

From here on create a file (pico one) make it executable and run it: 

-bash-3.2$ pwd
/u/dgerman/09101115

-bash-3.2$ ls -ld one
-rwxr-xr-x 1 dgerman faculty 34 Sep 10 11:38 one

-bash-3.2$ cat one
#!/usr/bin/python

print "Howdy."

-bash-3.2$ ./one
Howdy.

-bash-3.2$ 

Then we learn about raw_input(...) and the program becomes:

-bash-3.2$ ./one
Welcome to the program
Name: Adrian
Well, hello Adrian -- how are you today?

-bash-3.2$ ./one
Welcome to the program
Name: President Obama
Well, hello President Obama -- how are you today?

-bash-3.2$ cat one
#!/usr/bin/python

print "Welcome to the program"

name = raw_input("Name: ")

print "Well, hello", name, "-- how are you today?"
-bash-3.2$ 

So let's finish it: 

-bash-3.2$ cat one
#!/usr/bin/python

print "Welcome to the program"

name = raw_input("Name: ")
age  = raw_input("Age: ")

print "Well,", name, "you will be", int(age) + 1, "next year."


-bash-3.2$ ./one
Welcome to the program
Name: Adrian
Age: 9
Well, Adrian you will be 10 next year.

-bash-3.2$ 

So Python cares about types and we had to convert. 

b) Perl

-bash-3.2$ ls -ld two
-rwxr-xr-x 1 dgerman faculty 337 Sep 10 12:29 two

-bash-3.2$ cat two
#!/usr/bin/perl

print "Welcome to the Perl version of that program\n"; 

# name = raw_input("Name: ") 

print "Name: "; 
$name = <STDIN>;
chop($name); # that eliminates the newline that's collected by perl 
chop($name); 
chop($name); 

print "Age: "; 
$age = <STDIN>; 

print "Well ", $name, " you will be ", $age + 1, " next year\n"; 

-bash-3.2$ ./two
Welcome to the Perl version of that program
Name: Adrian German
Age: 9
Well Adrian Germ you will be 10 next year

-bash-3.2$