Programming Languages

These sessions are:

not about teaching you to program - you need to do that yourself
are about comparing some current popular languages
experimenting with these languages yourselves
so you teach yourself to program.

Resources

C man and - https://www.gnu.org/software/libc/manual/pdf/libc.pdf
Python - Built in
Shell - man and https://www.gnu.org/software/bash/manual/
PHP - https://www.php.net/

Sequence

C

hello

#include <stdio.h>
int main () {
   int i;
   i = 3;
   i = i + 5;
   printf("Hello %d\n", i)
}

Web

CGI bin

https://en.wikipedia.org/wiki/Common_Gateway_Interface

Beyond the scope

floating point math

#include <stdio.h>
#include <math.h>
int main() {
    float j;
    j = sin(M_PI / 4);
    printf("%3.3f\n", j);
}

Python

Hello

i = 3
i = i + 5
print ("Hello %d" %(i))

web

mod_python mod_wsgi

https://en.wikipedia.org/wiki/Mod_wsgi

Beyond the scope

floating point math

import math
j = math.sin(math.pi/4)
print ("%6.3f" %(j))

Shell

Hello

i=3

i=$[$i+5]

echo "Hello $i"

Web

CGI bin

Beyond the scope

floating point math

Don't be silly

or if you must:

perl -e 'use Math::Trig;
printf("%6.3f\n", sin(pi/4));'

php

Hello

<?php
$i = 3;

$i = $i + 5;

echo "Hello $i";

Web

<?php

$file = basename($_SERVER['PHP_SELF']);

?>

<form method=get action=<?php echo $file; ?>>

<input type=text name='i'>

<?php

echo $_GET['i'];

Floating point math

<?php

$j = sin(pi()/4);

echo round($j, 3)."\n";

?>

Hands On

Copy the the hello examples for all 4 languages into 4 files:

seq1.c
seq1.py
seq1.sh
seq1.php

Run the programs

Compile then run the the C program. Run with: ./seq1

gcc seq1.c -o seq1

Add a shebang to the python, bash and php programs.
Change the permissions on the python, bash and php programs chmod 755 or chmod a+x
Run with: ./seq1.py, ./seq1.sh etc.
Run the php program by putting it into your public_html directory and
Go to http://<yourmachine>/~<you>/seq1.php

Modify

Modify the C program to have it print your name and a different number. Maybe change the calculation from addition to multiplication.
Create and run the php Web form program - move it to your public_html directory

Things to debate - we can do this for the entire Fall and Winter.

Serial Comma: https://en.wikipedia.org/wiki/Serial_comma
Space after period: https://en.wikipedia.org/wiki/Sentence_spacing
Indentation Style: https://en.wikipedia.org/wiki/Indentation_style

Home Work

Modify the python, bash and php programs the same as you did for the C program