Mailing List Archive: 49091 messages
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search

[REBOL] Re: Ping?

From: holger:rebol at: 9-Feb-2001 10:33

On Fri, Feb 09, 2001 at 11:58:03AM -0600, Paul Tretter wrote:
> You cant. ICMP is not supported with REBOL which in the future I hope it is > and it should be a part of /core and not some add on feature.
The problem is that on some platforms (Unix, QNX, some others) ICMP requires root privileges, so on those platforms any REBOL scripts refering to it could only be run by root or by a REBOL binary installed with setuid root. ICMP as a protocol is really not all that useful. It is used internally by UDP and TCP, mostly, to return errors, and those errors are reported back by the stack to the socket, so they are already available in REBOL, as errors at the port level. The only potentially useful part of ICMP is "echo" (used by ping), and even that is overrated. Ping does not work through proxies and some firewalls, so in general it cannot be used to check for connectivity to a host. Ping is a useful diagnostic tool for net admins, but IMHO has no place in applications or scripting. Writing an application or a script that first tries to "ping" a host before trying to create a connection to it is a typical beginner's mistake. Those scripts break as soon as you switch platforms or network settings, whereas scripts that simply try to create a connection work everywhere. At the moment my feeling is that the marginal benefits of having ping in REBOL do not outweigh the resulting compatibility problems in proxy environments and across platforms. -- Holger Kruse [holger--rebol--com]