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;
my $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 v5.38.2 2023-11-28 Net::servent(3pm)
perl 5.38.2 - Generated Tue Dec 10 10:54:56 CST 2024