Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw


by root (Scribe)
on Dec 23, 1999 at 00:52 UTC ( #1232=perlfunc: print w/ replies, xml ) Need Help??


See the current Perl documentation for Net::protoent.

Here is our local, out-dated (pre-5.6) version:

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

 use Net::protoent;
 $p = getprotobyname(shift || 'tcp') || die "no proto";
 printf "proto for %s is %d, aliases are %s\n",
    $p->name, $p->proto, "@{$p->aliases}";

 use Net::protoent qw(:

This module's default exports override the core getprotoent(), getprotobyname(), and getnetbyport() functions, replacing them with versions that return ``Net::protoent'' objects. They take default second arguments of ``tcp''. This object has methods that return the similarly named structure field name from the C's protoent structure from netdb.h; namely name, aliases, 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 p_. Thus, $proto_obj->name() corresponds to $p_name if you import the fields. Array references are available as regular array variables, so for example @{ $proto_obj->aliases() } would be simply @p_aliases.

The getproto() function is a simple front-end that forwards a numeric argument to getprotobyport(), and the rest to getprotobyname().

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.


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

Log In?

What's my password?
Create A New User
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others examining the Monastery: (14)
As of 2015-11-25 18:36 GMT
Find Nodes?
    Voting Booth?

    What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

    Results (684 votes), past polls