= cs, csquery: connection server == SYNOPSYS *ndb/cs* [ **-f**__ database__ ] [ *-v* ] [ **-x**__ net__ ] *ndb/csquery* [ *-x* _net_ ] [ *-s* _server_ ] [ _address_ ... ]  _Cs_ spawns a process that serves a single file */net/cs*, in thecurrent name space, answering requests by client processes to translatesymbolic network and service names into instructions for connecting tothe given service. It is normally accessed indirectly by calls to_dial_(2). The network data is taken from the network database files, described in_ndb_(6). By default, it is */lib/ndb/local* but the *-f* option canspecify a different one. Each write to */net/cs* makes a query, expressed in one of two forms.The first form is a network address of the same form as the _addr_parameter to _dial_: __network__**!**__netaddr__**!**_service_ where_service_ and _network_ are optional for some networks. The writereturns an error if the address cannot be translated. Otherwise, thefile offset should be reset to 0 using _sys-seek_(2) and each subsequentread will return either end-of-file (if there are no furthertranslations), or a single line containing a translation of the form: _____________________________________________________**/net/**__proto__**/clone**__ address__**!**__port_______________________________________________________ The first field is the name of the _clone_ file for a network protocolor interface. To make a connection or announce a service, open thatfile, and write the text in the second field preceded by *connect* or*announce* as required. (All this activity is normally encapsulated in acall to _dial_(2).) _Cs_ produces a translation for each network and foreach network address on which a symbolic _netaddr_ is found. Whenannouncing a service, _netaddr_ can be *** to represent any localinterface, and the resulting recipes read from */net/cs* will notinclude an __address__**!** part. _Cs_ interprets a _netaddr_ of the form **$**__server__ specially: itlooks for an attribute _server_ in the database in the entry for thecurrent host, then in the entry for each network that contains it (ifspecified), and finally in a site-wide entry labelled with the attribute*infernosite*. If found, the value of the attribute replaces the_netaddr_ before further translation. In the second form of query, the text written contains space-separatedattribute/value pairs following an initial _____________________________________________________*!* __attr1__**=**_val1_ [ __attr2__**=**_val2_ ... ]_____________________________________________________ _Cs_ looks for an _ndb_(6) entry that contains attribute/value pairsmatching those in the query. Any value but _val1_ may be `*****', tosignify that the entry must contain the given attribute but with anyvalue. As before, the write returns an error if no entry matches.Otherwise, each subsequent read returns the whole of the next matchingentry, in _ndb_(6) form. The file */net/cs* persists until it is removed or unmounted from*/net*, or the _cs_ process is killed (see _kill_(1)). The *-v* optioncauses _cs_ to print each translation request and results (if any) onstandard error. The *-x* option gives an alternative mount point for_cs_, when there is more than one network stack (see _ip_(3)). It causesit _cs_ to serve __net__**/cs** instead of */net/cs*. _Cs_ is normally started once, after _dns_(8) if used, but before mostother applications including the various listeners described in_svc_(8). If another instance of _cs_(8) is started on the same mountpoint, the file it serves replaces the earlier one if permissions allow.(On Plan 9, Plan 9's native connection service will be used by defaultif Inferno's _cs_ is not started.) _Csquery_ queries the given _server_ (default: */net/cs*) for atranslation of each _address_ and prints the results, one per line. Ifno _address_ is given, _csquery_ prompts for address(es) to translatewhich it reads from the standard input, printing the results of eachtranslation on the standard output. The *-x* option gives an alternativemount point for _cs_, when there is more than one network stack (see_ip_(3)). _Cs_ uses _ndb_(6) to map protocol and service names to Internet portnumbers. When running hosted, if entries are not in _ndb_(6), _cs_applies the built-in _srv_(2), if available, to have the host system trythe translation. Consequently, entries in _ndb_(6) take precedence overthe host's system-wide configuration. (This is helpful for addingsymbolic names for Inferno services without requiring administrativeprivileges on the host system.) == EXAMPLE Check the translation of the symbolic name *$signer*: ....ndb/csquery> net!$signer!inflogin/net/tcp/clone 200.1.1.67!6673.... == FILES *#scs**::  service directory*/net/cs*::  connection service*/net/dns*::  domain name service*/lib/ndb/local*::  map from symbolic service names to servers == SOURCE */appl/cmd/ndb/cs.b* +*/appl/cmd/ndb/csquery.b* == SEE ALSO _dial_(2), _ndb_(6), _dns_(8)