Net::servent(3)
NNAAMMEE
Net::servent - by-name interface to Perl's built-in
getserv*() functions
SSYYNNOOPPSSIISS
use Net::servent;
$s = getservbyname(shift || 'ftp') || die "no service";
printf "port for %s is %s, aliases are %s\n",
$s->name, $s->port, "@{$s->aliases}";
use Net::servent qw(:FIELDS);
getservbyname(shift || 'ftp') || die "no service";
print "port for $s_name is $s_port, aliases are @s_aliases\n";
DDEESSCCRRIIPPTTIIOONN
This module's default exports override the core
getservent(), getservbyname(), and getnetbyport()
functions, replacing them with versions that return
"Net::servent" objects. They take default second
arguments of "tcp". This object has methods that return
the similarly named structure field name from the C's
servent structure from netdb.h; namely name, aliases,
port, and proto. The aliases method returns an array
reference, the rest scalars.
You may also import all the structure fields directly into
your namespace as regular variables using the :FIELDS
import tag. (Note that this still overrides your core
functions.) Access these fields as variables named with a
preceding n_. Thus, $serv_obj->name() corresponds to
$s_name if you import the fields. Array references are
available as regular array variables, so for example @{
$serv_obj->aliases() } would be simply @s_aliases.
The getserv() function is a simple front-end that forwards
a numeric argument to getservbyport(), and the rest to
getservbyname().
To access this functionality without the core overrides,
pass the use an empty import list, and then access
function functions with their full qualified names. On
the other hand, the built-ins are still available via the
CORE:: pseudo-package.
EEXXAAMMPPLLEESS
use Net::servent qw(:FIELDS);
while (@ARGV) {
my ($service, $proto) = ((split m!/!, shift), 'tcp');
my $valet = getserv($service, $proto);
unless ($valet) {
warn "$0: No service: $service/$proto\n"
next;
}
printf "service $service/$proto is port %d\n", $valet->port;
print "alias are @s_aliases\n" if @s_aliases;
}
NNOOTTEE
While this class is currently implemented using the
Class::Struct module to build a struct-like class, you
shouldn't rely upon this.
AAUUTTHHOORR
Tom Christiansen