Netinfo - Protocol, service and host info
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NAME
netinfo - Protocol, service and host info
SYNOPSIS
package require Tcl
package require netinfo 0.3
namespace import ::netinfo::*
protocolDataFilename ?fileName?
serviceDataFilename ?fileName?
hostDataFilename ?fileName?
loadProtocolData
loadServiceData
loadHostData
protocolFields
serviceFields
hostFields
protocol field value ?field value ...?
service field value ?field value ...?
host field value ?field value ...?
protocolData protocolInfo field ?field ...?
serviceData serviceInfo field ?field ...?
hostData hostInfo field ?field ...?
DESCRIPTION
The netinfo Tcl extension provides access to system proto-
col, service and host information which is retrieved from
system databases and made available for querying.
COMMANDS
protocolDataFilename ?fileName?, serviceDataFilename
?fileName?, hostDataFilename ?fileName?
These commands permit the setting and retrieval of
the file names used to import the system databases.
When called without a fileName argument they return
the current file name. When called with a fileName
argument they set the file name to fileName and
return the old file name.
The defaults are:
protocol: /etc/protocols
service: /etc/services loadProtocolData, loadServiceData, loadHostData
These commands import data from the system
databases. No files are loaded when the netinfo
extension is loaded. One of these must be called
(once) to import the system data after (optionally)
setting the file name. It is necessary to load only
the data for which querying is desired, i.e. they
don't all have to be loaded.
protocolFields, serviceFields, hostFields
These commands return a list of field names for
their respective data sets. The order of the fields
is the same order in which data is returned from
the querying commands. The fields correspond to the
fields in their respective files, with the excep-
tion of host which has an additional -domain ele-
ment which can be either inet or inet6. The -type
element for service data is usually tcp or udp.
The -alias element really means 'aliases'.
The fields are:
protocol: -name -address -alias -comment -domain
service: -name -number -alias -comment protocol field value ?field value ...?, service field
value ?field value ...?, host field value ?field value
...?
These commands query their respective data sets and
return lists containing matched data, if any. The
field parameter must be one of the available fields
for the particular data set as returned by one of
the 'xxxFields' commands. The value parameter is
matched against the indicated field using the rules
of [string match]. Additional field value pairs may
be given for a more precise query. If any of the
value parameters contain any glob chars ('*', '?'
or something enclosed in '[]') then the return
value will be a list of lists, each element of the
outer list being one result of the matched query.
If no glob chars are present in the value parameter
then a single list result and only the first match
is returned. If no matches occur then an empty list
'{}' is returned. For host queries without a sup-
plied -domain argument, inet domains will match
first. For service queries without a supplied -type
argument, tcp types will match first.
protocolData protocolInfo field ?field ...?, serviceData
service- Info field ?field ...?, hostData hostInfo field
?field ...?
These commands extract data from query results.
The 'xxxInfo' parameter is a single list result as
returned by one of the querying commands. The
field parameter must be one of the available fields
for the particular data set as returned by one of
the 'xxxFields' commands. If only a single field
parameter is provided then the result will be the
value of the specified field. If more than one
field parameter is provided then the result will be
a list containing the values of the specified
fields in the same order as the specified field
parameters.
EXAMPLES
# Results noted with #=>
package require netinfo
namespace import ::netinfo::*
loadProtocolData; loadServiceData; loadHostData
protocolData [protocol -number 123] -comment
#=> Performance Transparency Protocol
protocolData [protocol -number 123] -comment -name
#=> {Performance Transparency Protocol} ptp
service -port 9
#=> discard 9 {sink null} {} tcp
service -port 9 -type udp
#=> discard 9 {sink null} {} udp
service -port 9 -type *
#=> {discard 9 {sink null} {} tcp} {discard 9 {sink null} {} udp}
serviceData [lindex [service -port 9 -type *] 1] -type
#=> udp
hostData [host -alias localhost] -address
#=> 127.0.0.1
hostData [host -alias localhost -domain inet6] -address
#=> ::1
# To obtain a list of all services (same for protocols and hosts):
service -name *
CAVEATS
No error checking is done in regards to field names or
file names or anything else. This 'crashing as error
reporting' strategy is motivated by: laziness, a desire
for keeping things quick and simple and the fact this is
an all-around simple little extension that I didn't feel
like bogging down with all that extra stuff. Besides,
you're supposed to know what you're doing. :)
KEYWORDS
network protocol service host