http://search.cpan.org/

[root@lb2 ~]# perl -MCPAN -e shell

cpan[1]> install Encode::IMAPUTF7

• Чтение данных с STDIN
• Регулярный разбор полей строки

# cat readstdin.pl

#!/usr/bin/perl

while(<>) {
        print $_;
        if (/^(allow|deny) ([^ ]+) ([^ ]+) ([^ ]+) (.*$)/) {
                $act=$1;
                $proto=$2;
                $src=$3;$dst=$4;$port=$5;
                $count++;
                print "ipfw -q add $act $proto from $src to $dst $port\n";
        }
}

• Усиление контроля синтаксиса
• Обработка аргументов
• Использование внешних утилит
• Регулярный разбор полей строковой переменной

# cat show_cdp_neighbors.pl

#!/usr/bin/perl

use strict;
use warnings;

my ($ip) = @ARGV;

if (not defined $ip) {
  die "Need ip\n";
}

my $sw=`snmpget -On -m ALL -c public -v2c $ip sysName.0 2>/dev/null`;

print "neibors for switch: $sw\n";

foreach my $i (`snmpwalk -On -v2c -c public -m ALL $ip .1.3.6.1.4.1.9.9.23.1.2.1.1.6 2>/dev/null`) {
                $i=~/.*STRING: (.*)/;
                print "$1\n";
}

• Использование MySQL
• autoincrement
• transaction
• error handling

CREATE TABLE
    table1 (
        a INT NOT NULL AUTO_INCREMENT,
        b INT NOT NULL,
        PRIMARY KEY(a)
    );
CREATE TABLE
    table2 (
        b INT NOT NULL,
        a INT NOT NULL,
        PRIMARY KEY(b)
    );
CREATE TABLE
    table3 (
        b INT NOT NULL,
        a INT NOT NULL
    );

# cat example3.pl

#!/usr/bin/perl

use DBI;

print "Start\n";

my $dsn = 'DBI:mysql:test:127.0.0.1:3306';
my $db_user_name = 'test';
my $db_password = 'test';

printf "Connect to test\n";

my %attr = (AutoCommit=>0,RaiseError=>1,HandleError => \&DBerror);
my $dbh = DBI->connect($dsn, $db_user_name, $db_password, \%attr);

my $sth = $dbh->prepare(qq{SET NAMES 'utf8'});
$sth->execute() or print "Cannot execute: " . $sth->errstr();

printf "Loop\n";
MAINLOOP:
for (my $c = 10; $c >= 1; $c--) {

        my $b = int(rand(10));


        $sth = $dbh->prepare(qq{insert into table1 (b) values ($b)});
        $sth->execute() or next MAINLOOP;

        $sth = $dbh->prepare(qq{select LAST_INSERT_ID()});
        $sth->execute() or next MAINLOOP;
        (my $a)=$sth->fetchrow_array();

        print "a = $a; b = $b\n";

        $sth = $dbh->prepare(qq{insert into table2 (b, a) values ($b, $a)});
        $sth->execute() or next MAINLOOP;

        $sth = $dbh->prepare(qq{insert into table3 (a, b) values ($a, $b)});
        $sth->execute() or next MAINLOOP;

        $dbh->commit() or next;
}

$sth->finish();
$dbh->disconnect();

exit 0;

sub DBerror(){
    my $err = shift;
    print "ROLLBACK $err\n";
    $dbh->rollback();
}