Sams Teach Yourself Perl in 21 Days, Second Edition

An Example: Converting Fahrenheit to Celsius

With numbers, strings, and scalar variables under your belt, you can now start to write simple Perl scripts. Here's a script that prompts you for a Fahrenheit number and then converts it to Celsius. Here's what it looks like when it's run:

% temperature.pl
Enter a temperature in Fahrenheit: 212
212 degrees Fahrenheit is equivalent to 100 degrees Celsius
%

Listing 2.1 shows the Perl code for this script:

Listing 2.1. The temperature.pl Script

1: #!/usr/local/bin/perl -w 2: 3: $fahr = 0; 4: $cel = 0; 5: 6: print 'Enter a temperature in Fahrenheit: '; 7: chomp ($fahr = <STDIN>); 8: $cel = ($fahr - 32) * 5 / 9; 9: print "$fahr degrees Fahrenheit is equivalent to "; 10: printf("%.0f degrees Celsius\n", ...