Net::servent(3p) Perl Programmers Reference Guide Net::servent(3p)

Net::servent(3p) Perl Programmers Reference Guide Net::servent(3p) #

Net::servent(3p) Perl Programmers Reference Guide Net::servent(3p)

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 ggeettsseerrvveenntt(()),
 ggeettsseerrvvbbyynnaammee(()), and ggeettnneettbbyyppoorrtt(()) 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 _n_e_t_d_b_._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 ggeettsseerrvv(()) function is a simple front-end that forwards a numeric
 argument to ggeettsseerrvvbbyyppoorrtt(()), and the rest to ggeettsseerrvvbbyynnaammee(()).

 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

perl v5.36.3 2019-02-13 Net::servent(3p)