Net::servent(3p)Perl Programmers Reference Guide Net::servent(3p)NAMENet::servent - by-name interface to Perl's built-in get-
serv*() functions
SYNOPSIS
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 $s_port, aliases are @s_aliases\n";
DESCRIPTION
This module's default exports override the core getser-
vent(), getservbyname(), and getnetbyport() functions,
replacing them with versions that return "Net::servent"
objects. They take default second arguments of "tcp". This
object has methods that return the similarly named structure
field name from the C's servent structure from netdb.h;
namely name, aliases, port, and proto. The aliases method
returns an array reference, the rest scalars.
You may also import all the structure fields directly into
your namespace as regular variables using the :FIELDS import
tag. (Note that this still overrides your core functions.)
Access these fields as variables named with a preceding
"s_". Thus, "$serv_obj->name()" corresponds to $s_name if
you import the fields. Array references are available as
regular array variables, so for example "@{
$serv_obj->aliases()}" would be simply @s_aliases.
The getserv() function is a simple front-end that forwards a
numeric argument to getservbyport(), and the rest to get-
servbyname().
To access this functionality without the core overrides,
pass the "use" an empty import list, and then access func-
tion functions with their full qualified names. On the other
hand, the built-ins are still available via the "CORE::"
pseudo-package.
EXAMPLES
use Net::servent qw(:FIELDS);
perl v5.8.8 2005-02-05 1
Net::servent(3p)Perl Programmers Reference Guide Net::servent(3p)
while (@ARGV) {
my ($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;
}
NOTE
While this class is currently implemented using the
Class::Struct module to build a struct-like class, you
shouldn't rely upon this.
AUTHOR
Tom Christiansen
perl v5.8.8 2005-02-05 2