Selection ... choices

Things to debate - Remember.

• 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

Comments

• C - //
• Python - #
• PHP - // or #
• Bash - #
  

C

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
  int cats = atoi(argv[1]);
  if (cats > 3) {
    printf ("%d is too many cats\n", cats);
  } else {
    printf ("%d cats is OK\n", cats);
  }
}

Python

import sys
cats = int(sys.argv[1])
if cats > 3:
  print("%d is too many cats" %(cats))
else:
  print("%d cats is OK" %(cats))

Bash

if [ $1 -gt 3 ];
then
  echo $1 is too many cats
else
  echo $1 cats is OK
fi

PHP

<?php
$cats = $_SERVER['QUERY_STRING'];
if ($cats > 3) {
  echo "$cats is too many cats\n";
} else {
  echo "$cats cats is OK\n";
}
?>

Hands On

Copy the above code into the respective files:

• selection.c
• selection.py
• selection.sh
• selection.php

Run the programs

• Do the same as for sequence:
  
• Compile and run selection.c
• Add a shebang to the python and bash programs
  
• change the permissions to 755 and run with ./selection.py <number> etc.
• Put  seq1.php into your public_html directory and run it from a browser with <yourmachine>/<yourlogon/~

Homework

•  Perhaps a message if the CPU temperature is above a given value.  CPU temp can be found with the following simple script:

cpu=$(</sys/class/thermal/thermal_zone0/temp)
echo "$((cpu/1000)) c"

On the Pi running Raspbian the temperature can be found at at the same place

• Or displays the time of day and says good morning, afternoon or evening in Spanish, or Swahili,  or whatever depending on your preference.  See appendix for info on date and time.  Let's assume sunset is 19:00 as actually finding sunset is beyond the scope ...

Appendix

Date and time

• C   -
  
• Python -
  
• Bash -ps date +%H:%M
  
  
• PHP -