Perl reference

Wednesday, 16 June 2010

 Reference material

• Perl syntax summary by O'Reilly / -other-: $var, @arr $arr[ $index], %hash $hash{$key}
• Database Management in PERL - DBI
• Database Management in PERL - DBI - timeout handling

Online guide for object oriented perl:

• Khurt Williams.
• Object Oriented Programming in PERL
• Recap of Conventions

my $am = Graph::AdjacencyMatrix->new($g, distance_matrix => 1);

--
implemented as:

use 5.006;
use strict;
use warnings;

package Graph::AdjacencyMatrix;

use Parent::Class;

our $VERSION = '4.4';
our @ISA     = qw(Parent::Class);
our @EXPORT  = qw(export_functions_by_default); # otherway export everything

..
sub new {
my ($class, $g, %opt) = @_;

my $self = $class->SUPER::new( $_[1], $_[2], $_[3] );

--OR--
my $self = {
_firstName => shift,
_lastName  => shift,
_ssn       => shift,
};


...
bless $self, $class;
}

sub MyMethod
{
my $self = shift;
$self->SUPER::MyMethod();
print "   MySubClass::MyMethod called!\n";
}

isa (package name)

can (function name)

Formatting Strings w/ Formatting Characters \Q..\E - here

Regular expression especials - here

Here operator here

File operators: z -e -f -d ... here

Perl reference:

• ref EXPR -- if (ref($r) eq "HASH") -- Returns SCALAR ARRAY HASH CODE REF GLOB LVALUE FORMAT IO VSTRING Regexp
• our $var_name -
• our $VERSION = qv("v1.2.3"); # shorthand
• $Module::VERSION.
• use Module VERSION LIST

• my $x = "abc" x 3; #$x is now the string "abcabcabc"
• my @a = ("abc") x 3; #@a is now ("abc", "abc", "abc")
• Prototypes: sub mylink ($$) -- mylink $old, $new
• Operator (..) :

my $i = 4;
my $x = ("a" .. "z")[$i]; #$x is now "e"
my $y = ("a" .. "z")[-$i]; #$y is now "w"
my @a = ("a" .. "z")[0 .. $i]; #@a is now ("a", "b", "c", "d", "e")
my @b = ("a" .. "z")[1, 0, 3]; #@b is now ("b", "a", "d")


Number of elements in an array:

$#ARGV    - scalar index del último elementos
scalar( @ARGV ) - número de elementos