Net::servent(3pm) Perl Programmers Reference Guide Net::servent(3pm)
NAME
Net::servent - by-name interface to Perl's built-in getserv*() 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 $s_port, aliases are @s_aliases\n";
DESCRIPTION
This module's default exports override the core getservent(), getservbyname(), and getnetbyport()
functions, replacing them with versions that return "Net::servent" objects. They take default second
arguments of "tcp". This object has methods that return the similarly named structure field name
from the C's servent structure from netdb.h; namely name, aliases, port, and proto. The aliases
method returns an array reference, the rest scalars.
You may also import all the structure fields directly into your namespace as regular variables using
the :FIELDS import tag. (Note that this still overrides your core functions.) Access these fields
as variables named with a preceding "s_". Thus, "$serv_obj->name()" corresponds to $s_name if you
import the fields. Array references are available as regular array variables, so for example "@{
$serv_obj->aliases()}" would be simply @s_aliases.
The getserv() function is a simple front-end that forwards a numeric argument to getservbyport(), and
the rest to getservbyname().
To access this functionality without the core overrides, pass the "use" an empty import list, and
then access function functions with their full qualified names. On the other hand, the built-ins are
still available via the "CORE::" pseudo-package.
EXAMPLES
use Net::servent qw(:FIELDS);
while (@ARGV) {
my ($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;
}
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 2001-09-21 Net::servent(3pm)
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