UNIX for Advanced & Expert Users

if ($name eq $goodguy) {

#!/usr/bin/perl

# @(#) p1       Demonstrate value of running with warnings on.

use warnings;

$name = 'Mark';

$goodguy = 'Tody';

if ( $name == $goodguy ) {
    print "Hello, Sir.\n";
}
else {
    print "Begone, evil peon!\n";
}

exit(0);

% ./p1
Argument "Tody" isn't numeric in numeric eq (==) at ./p1 line 11.
Argument "Mark" isn't numeric in numeric eq (==) at ./p1 line 11.
Hello, Sir.

if ( 'c' >  13 ) 
{
    /* do stuff */
}

my $a = "fine";

print " $a : ord : " . ord($a) . "\n";

my $length = length($a);
for ( my $i = 0; $i <= $length; $i++ ) {
  my $c = substr($a, $i, 1);
  print " char: $c ord: " . ord($c) . "\n";

}

#!/usr/bin/perl

# @(#) p3       Demonstrate comparison operators.

use warnings;
use strict;

my($first) = "b";
my($last) = "a";

if ( $first == $last ) {
        print " Value $first seems equal to $last with \"==\"\n\n";
}

if ( ord($first) > ord($last) ) {
        print " ords of value $first seems more than $last with \">\"\n\n";
}

if ( $first gt $last ) {
        print " Value $first seems more than $last with \"gt\"\n\n";
}

# Do a few comparisons.

comparison( "aa", "ab");
comparison( "ab", "able");
comparison( "ac", "able");
comparison( "1", "2");
comparison( "11", "2");
comparison( "1 begins this string", "2");

sub comparison {
        my($a,$b) = @_;

        if ( $a le $b ) {
                print " string :$a: is less than string :$b:\n\n";
        } else {
                print " string :$a: is greater than string :$b:\n\n";
        }
}

exit(0);

% ./p3
Argument "a" isn't numeric in numeric eq (==) at ./p3 line 11.
Argument "b" isn't numeric in numeric eq (==) at ./p3 line 11.
 Value b seems equal to a with "=="

 ords of value b seems more than a with ">"

 Value b seems more than a with "gt"

 string :aa: is less than string :ab:

 string :ab: is less than string :able:

 string :ac: is greater than string :able:

 string :1: is less than string :2:

 string :11: is less than string :2:

 string :1 begins this string: is less than string :2: