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