GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
Net::servent(3) Perl Programmers Reference Guide Net::servent(3)

Net::servent - by-name interface to Perl's built-in getserv*() functions

 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";

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.

 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;
 }

While this class is currently implemented using the Class::Struct module to build a struct-like class, you shouldn't rely upon this.

Tom Christiansen
2022-02-19 perl v5.34.1

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.