Version 2.4

28 December 1999

Jonas Öberg (jonas@gnu.org)


JWHOIS is an Internet Whois client that queries hosts for information according to RFC 954 - NICNAME/WHOIS. JWHOIS is configured via a configuration file that contains information about all known Whois servers. Upon execution, the host to query is selected based on the information in the configuration file.

The configuration file is highly customizable and makes heavy use of regular expressions.


JWHOIS uses the following command-line options:

Print the program version and licensing information.
Print a usage message summarizing the command-line options.
`-c FILE'
Reads configuration from FILE instead of from the default system global configuration file.
`-h HOST'
Overrides any specifications in the configuration file and queries HOST directly.
`-p PORT'
Specifies a port number to use when querying a HOST
This option forces the client to look up an entry from the source Whois server, even if a current copy is available in the system cache.
This disables the cache functionality.
Enables verbose debugging output where available.

The query can optionally contain the character `@' followed by a host name to direct the search to that host. This works exactly like specifying the host with `--host'.

RIPE Extensions

RIPE (Réseaux IP Européens) has defined a number of options that can be used against a RIPE-compatible whois server (ripe.net, apnic.net and others). Unfortunately, there is really no way of telling whether a host we are connecting to is RIPE-compatible or not. RIPE extensions are therefore not directly incorporated into the JWHOIS client. A list of the options can be found in RIPE Document 157 which you can get from the RIPE ftp server, ftp://ftp.ripe.net/ripe/docs/.

It is possible to use these options together with JWHOIS by changing the format of the query slightly. If you were to search for all entries in the RIPE database which lists the admin-c, tech-c or zone-c as CO19-RIPE, you could use the following command syntax:

$ jwhois -h whois.ripe.net -- -i admin-c,tech-c,zone-c CO19-RIPE

`--' is used to separate the RIPE options from the jwhois options.

Site Configuration

JWHOIS is configurable via its configuration file, normally called `jwhois.conf'. This file is looked for in the sysconfdir that was specified when compiling the program (default is `/usr/local/etc/' on most systems).

If no configuration file can be found, JWHOIS will default all queries to whois.internic.net.

An example configuration file that includes most known Whois servers can be found in the example subdirectory of the official distribution.

The configuration file is split into a number of blocks. Each block can contain a number of different options which are explained in the sections below. You can also get an overview of the syntax by looking at the example configuration file included in the distribution.


The only available global options are related to the cache features in jwhois See section Cache Functionality. By default, the location of the configuration file is `/usr/local/var/jwhois.db', but this can be changed at compile time. The option @option{cachefile} also changes the location.

The default expire time for all cached objects it 7 days (168 hours). this can be changed with the @option{cacheexpire} option. The value is the number of hours that objects is considered to be current.


cachefile = "/var/lib/jwhois.db";
cacheexpire = 168;


When making a query, JWHOIS looks at the @option{whois-servers} block to determine which host to send the query to. The option @option{type} can be set to change between two different kinds of matching; @option{cidr} or @option{regex}.

@option{regex} matches using standard regular expressions. @option{cidr} matches using CIDR net blocks.

The value of all objects can take one of two forms. Either a hostname or the special option @option{struct}. The later asks JWHOIS to look at another option block in the configuration file.

When matching using CIDR net blocks, the key can take the special value @option{default} which matches everything.

whois-servers {
        type = regex;
        ".*-[A-Z]+$" = "struct handles";
        ".*" = "whois.internic.net";
handles {
        type = regex;
        ".*-RIPE$" = "whois.ripe.net";
        default = "whois.arin.net";


@option{content-redirect} is a special block designed to parse the output returned by a Whois server looking for special regular expressions and then sending the same query to the Whois server gotten from the regular expression.

The key value is the name of the Whois server that this expression is applicable to. This is matched using regular expressions. The value is the regexp that is looked for in the output, with hostname and optional port number enclosed in so called subexpressions or groups.

content-redirect {
        ".*" = ".*Whois Server: \\(.*\\)";

Cache Functionality

JWHOIS implements support for maintaining a cache of Whois data received from Whois servers. This is NOT enabled by default but has to be compiled into the client specifically. The design is such that a central database is maintained by the client and because all users should have access to that database, the program must have the set-group-on-execution bit set and the database must be both read and writable by the group.

The configuration options available are CACHEFILE and CACHEEXPIRE which sets the database filename and the expire time for cached object. When an object expires from the cache, it is reloaded from the Whois server the next time it is requested. The expire time is measured in hours.

Reporting bugs

Email bug reports to bug-jwhois@gnu.org.

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