perl -v

#!/usr/bin/perl
print "Hello, World!\n";

perl hello.pl

my $name = "John";
my $age = 30;

my @fruits = ("apple", "banana", "cherry");
print $fruits[0];  # 輸出: apple

my %capitals = ("France" => "Paris", "Germany" => "Berlin");
print $capitals{"France"};  # 輸出: Paris

my $num = 10;
if ($num > 5) {
    print "Number is greater than 5\n";
} elsif ($num == 5) {
    print "Number is 5\n";
} else {
    print "Number is less than 5\n";
}

# for循環(huán)
for (my $i = 0; $i < 5; $i++) {
    print "$i\n";
}
# while循環(huán)
my $j = 0;
while ($j < 5) {
    print "$j\n";
    $j++;
}
# foreach循環(huán)
my @colors = ("red", "green", "blue");
foreach my $color (@colors) {
    print "$color\n";
}

sub greet {
    my $name = shift;  # 獲取傳入的參數(shù)
    print "Hello, $name!\n";
}
greet("Alice");

open(my $fh, '<', 'input.txt') or die "Cannot open input.txt: $!";
while (my $line = <$fh>) {
    print $line;
}
close($fh);

open(my $fh, '>', 'output.txt') or die "Cannot open output.txt: $!";
print $fh "This is a test.\n";
close($fh);

my $text = "The quick brown fox jumps over the lazy dog";
if ($text =~ /quick/) {
    print "Found 'quick'\n";
}

$text =~ s/dog/cat/;
print "$text\n";  # 輸出: The quick brown fox jumps over the lazy cat

use strict;
use warnings;
use CGI qw(:standard);
print header;
print start_html("Hello, world");
print h1("Hello, world");
print end_html;

cpan install CGI

perl -d script.pl