archie/release/base/manpages/archie.n

.\" Copyright (c) 1994, 1996 Bunyip Information Systems Inc.
.\" All rights reserved.  
.\"	
.\" Archie 3.5
.\" August 1996
.\"	
.\"	@(#)archie.n
.\"
.TH ARCHIE N "August 1996"
.SH NAME
archie \- Internet archive server listing service
.SH SYNOPSIS
.B archie
.SH DESCRIPTION
This manual page describes Version 3 of the Archie system. This Internet
information service allows the user to query a catalog containing a list of
files which are available on hosts connected to the Internet. Software located
through this service can be obtained by means of
.IR ftp (1);
for hosts with access to BITNET/NetNorth/EARN,
it can be obtained by electronic mail through the Princeton
.BR bitftp (1L)
service. Send mail to
.sp
.in +2in
bitftp@pucc.princeton.edu
.in 0
.LP
Other Internet users who are not directly connected may use the services
of various ftp-by-mail servers including
.sp
.in +2in
ftpmail@decwrl.dec.com
.in 0
.LP
Some Archie systems track archive sites globally, others only track the
archive sites in their country, region or continent, in order to reduce the
load on trans-oceanic links. There are a number of Archie hosts serving
different continental user communities. The
.B servers
command will list the most
up-to-date information on
Archie servers worldwide.
.sp
.ta +3n; +25n
\fBarchie.au\fP	Australia
.br
\fBarchie.edvz.uni-linz.ac.at\fP	Austria
.br
\fBarchie.univie.ac.at\fP	Austria
.br
\fBarchie.cs.mcgill.ca\fP	Canada
.br
.br
\fBarchie.funet.fi\fP	Finland
.br
\fBarchie.univ-rennes1.fr\fP	France
.br
\fBarchie.th-darmstadt.de\fP	Germany
.br
\fBarchie.ac.il\fP	Israel
.br
\fBarchie.unipi.it\fP	Italy
.br
\fBarchie.wide.ad.jp\fP	Japan
.br
\fBarchie.hana.nm.kr\fP	Korea
.br
\fBarchie.sogang.ac.kr\fP	Korea
.br
\fBarchie.uninett.no\fP	Norway
.br
\fBarchie.rediris.es\fP	Spain
.br
\fBarchie.luth.se\fP	Sweden
.br
\fBarchie.switch.ch\fP	Switzerland
.br
\fBarchie.ncu.edu.tw\fP	Taiwan
.br
\fBarchie.doc.ic.ac.uk\fP	United Kingdom
.br
\fBarchie.hensa.ac.uk\fP	United Kingdom
.br
\fBarchie.unl.edu\fP	USA (NE)
.br
\fBarchie.internic.net\fP	USA (NJ)
.br
\fBarchie.rutgers.edu\fP	USA (NJ)
.br
\fBarchie.ans.net\fP	USA (NY)
.br
\fBarchie.sura.net\fP	USA (MD)
.ta
.br
.LP
Archie can be accessed interactively, via electronic mail or
through Archie client programs available widely on the Internet.
.sp
.SS "Using the Interactive (telnet) Interface"
.sp
In order to use the interactive system you should use the
following procedure:
.TP
1)
\fBtelnet\fP to the Archie system closest to you. Do not use \fBftp\fP
for this, it will not work.
.TP
2)
Login as user
.BR archie
(no capital letters); no password is required. The system should print a
banner message and status report before presenting you with the command
prompt.  Some newer operating systems will prompt for a password. Just hit the
return key and continue.
.TP
3)
Type \fBhelp\fP for complete information on the system.
.LP
For full details,
refer to the section entitled
.SM "ARCHIE COMMANDS"
which appears below.
.sp
.SS "Using the Electronic Mail Interface"
.sp
In order to use the email interface, send requests to:
.IP
\fCarchie@\fP\fI<archie_server>\fP
.LP
where \fI<archie_server>\fP is one of the hosts listed above, or one returned
by the \fBservers\fP command.  Send the word ``help'' in a message to obtain
a list of available commands and features.  This is a completely automated
interface, acting without human intervention.
.LP
For full details,
refer to the section entitled
.SM "ARCHIE COMMANDS"
which appears below.
.SS "Using the Archie clients"
.sp
The source code as well as machine executables for a variety of Archie
client programs can be obtained via anonymous
.BR ftp (1)
from many of the Archie
server hosts listed above. They are usually stored in the 
.B archie/clients 
or 
.B pub/archie/clients
directories. These clients communicate, via the \fIProspero\fP distributed
file system protocol, with Archie servers, which perform the specified queries
and return the results to the user. Currently there are UNIX and VMS command
line, curses and X window clients as well as Mac and PC Windows versions. For
more information on \fIProspero\fP send your queries to
info-prospero-request@isi.edu
.sp
.SS "Communicating with the Database Administrators"
Mail to Archie administrators at a particular Archie server should be sent to
the address
.IP
\fCarchie\(emadmin@\fP\fI<archie_server>\fP
.LP
where \fI<archie_server>\fP is one of the hosts listed above.
.sp
To send mail to the implementors of the Archie system, please send mail to
.IP
\fCarchie\(emgroup@bunyip.com\fP
.LP
The Archie server system is a product of Bunyip Information Systems.
.sp
Requests for additions to the set of hosts surveyed for the catalog, or other
administrative matters, should be sent to:
.IP
\fCarchie\(emadmin@bunyip.com\fP
.SH "ARCHIE COMMANDS"
In version 3 of the Archie system the telnet and email clients accept a common
set of commands. Additionally, there are specialized commands specfic to the
particular interfaces. See
.SM "THE INTERACTIVE INTERFACE"
and 
.SM "THE EMAIL INTERFACE"
sections below for a list of these commands.
.sp
Note that some Archie server sites may disable some of the commands for
reasons particular to their site.  As well, some sites limit the number of
concurrent interactive (telnet) sessions to better utilize limited resources.
.SS "Commands"
Arguments to commands shown in square brackets (`[]') are optional; all others
are mandatory.
.TP
.BI find " <pattern>"
.TP
.BI prog " <pattern>"
This command produces a list of files matching the pattern \fI<pattern>\fP.
The \fI<pattern>\fP may be interpreted as a simple substring, a case sensitive
substring, an exact string or a regular expression, depending on the value of
the \fBsearch\fP variable.  The output normally contains such information as
the file name that was matched, the directory path leading to it, the site
containing it and the time at which that site was last updated.  The format of
the output can be selected through the \fBoutput_format\fP variable.  The
results are sorted according to the value of the \fBsortby\fP variable, and
are limited in number by the \fBmaxhits\fP variable.
.sp
\fBprog\fP is identical to
.BR find .
It is included for backward compatibility with older versions of the system.
.TP
.BR help \ [\fI<topic>\fP\ [\fI<subtopic>\fP]\ ...]
Invoke the help system and present help on the specified topic.  A list of
words is considered to be one topic, not a list of individual topics. Thus,
.RS
.IP
\fChelp set maxhits\fP
.RE
.IP
requests help on the subtopic \fImaxhits\fP of topic \fIset\fP, not on two
separate topics.  After help is presented, the user is placed in the help
system at the deepest level containing subtopics.
.sp
For example, after typing
.RS
.IP
\fChelp set maxhits\fP
.RE
.IP
and being shown the information for that topic, the user is placed at the
level \fIset\fP in the help hierarchy.
.TP
.BR list " [\fI<pattern>\fP]"
Produce a list of sites whose contents are contained in the Archie
catalog. With no argument all the sites are listed. If given, the
\fI<pattern>\fP argument is interpreted as a regular expression (see
.SM "REGULAR EXPRESSIONS"
below) against which to match site names: only those names matching are
printed. The format of the output can be selected through the
\fBoutput_format\fP variable.
.IP
Note that the numerical (IP) address associated with a site name was valid at
the last time the site was updated in the Archie catalog but may have been
changed subsequently.  Furthermore, the listed IP address is the primary
address as listed in the Domain Name System (secondary addresses are not
stored).  For example,
.RS
.IP
\fClist\fP
.RE
.IP
lists all sites in the catalog, while
.RS
.IP
\fClist \e.de$\fP
.RE
.IP
lists all German sites.
.TP
.BI mail " <address>"
Mail the result of the last command that produced output (e.g. \fBfind\fP,
\fBlist\fP) to \fI<address>\fP. This must be a vaid email address.
.TP
.BR manpage " [ roff | ascii ]"
Display the Archie manual page (this file). The optional arguments specify the
format of the returned document. `roff' specifies UNIX
.BR troff (1)
format, while `ascii' specifies plain, preformatted ASCII output. With
no arguments it defaults to `ascii'.
.TP
.B domains
Asks the current server for the list of the Archie \fIpseudo-domains\fP that
it supports. See the entry for the \fBmatch_domain\fP variable below. This
command takes no arguments.  For example,
.RS
.IP
\fCdomains\fP
.RE
.IP
requests the list of pseudo-domains from the server. The result looks (in
part) something like this:
.RS
.sp
.nf
africa               Africa               za
anzac                OZ & New Zealand     au:nz
asia                 Asia                 kr:hk:sg:jp:cn:my:tw:in
centralamerica       Central America      sv:gt:hn
easteurope           Eastern Europe       bg:hu:pl:cs:ro:si:hr
mideast              Middle East          eg:.il:kw:sa
northamerica         North America        usa:ca:mx
scandinavia          Scandinavia          no:dk:se:fi:ee:is
southamerica         South American       ar:bo:br:cl:co:cr:cu:ec:pe
usa                  United States        edu:com:mil:gov:us
westeurope           Western Europe       westeurope1:westeurope2
world                The World            world1:world2
.fi
.sp
.RE
.IP
The first column gives the names of pseduo-domains supported by the
server. The second gives the ``natural language'' description of the
pseudo-domain and the third column is the actual definitions of those
domains. Here, the "asia" domain is comprised of the Domain Name System
country codes for Korea (`kr'), Hong Kong (`hk'), Singapore (`sg'),
etc. Pseudo-domains may also be constructed from other pseudo-domains: thus
one component of the the `northamerica' domain is itself constructed from the
`usa' pseudo-domain.
.TP
.B motd
Re-display the `message of the day', which is normally printed when the user
initially logs on to the client (in the case of the interactive interface) or
at the start of the returned message (in the email interface).
.TP
.B servers
Display a list of all publicly accessible Archie servers worldwide. The names
of the hosts, their IP addresses and geographical locations are listed.
.TP
.BR set " \fI<variable-name>\fP [\fI<value>\fP]"
Set the specified variable.  Variables are used to control various aspects of
the way Archie operates; the interpretation of pattern arguments, the format
of output from various commands, etc.  See the section below on variables for
a description of each one, as well as the entries for
.B unset
and
.BR show .
.TP
.BR show " [\fI<variable-name>\fP ...]"
Without any argument, display the status of all the user-settable variables,
including such information as its type (boolean, numeric or string), whether
or not it is set, and its current value (if its type requires a value).
Otherwise, show the status of each of the specified arguments.
.IP
Example:
.RS
.IP
\fCshow maxhits\fP
.RE
.TP
.BI site " <sitename>"
This command is currently unimplemented under version 3 of the Archie system.
.TP
.BI unset " <variable>"
Remove any value associated with the specified variable.  This may cause
counter-intuitive behavior in some cases; for example, if \fBmaxhits\fP is not
defined by the user, the \fBfind\fP command will print the internal default
number of matches rather than an unlimited number of matches.
.TP
.B version
Print the current version of the client.
.SS "Variable Types"
The behavior of Archie can be modified by certain variables, the values of
which may be changed using the \fBset\fP command, or removed entirely by the
\fBunset\fP command.  There are three variable types:
.TP 15
.B boolean
(Set or unset)
.TP
.B numeric
(Integer within a defined range)
.TP
.B string
(String of characters which may or may not be restricted).
.sp
If the value of a string variable must contain leading or trailing spaces then
it should be quoted.  Two ways to quote text are to surround it with a pair of
double quotes (`"'), or to precede individual characters with a backslash (`\e').
(A double quote, or a backslash may itself be quoted by preceding it by a
backslash.)  The resulting value is that of the string with the quotes
stripped off.
.sp
.SS "Numeric Variables"
.TP
.B maxhits
Allow the \fBfind\fP command to generate at most the specified number of
matches.  The permissible range is from 0 to 1000, with a default value of
100.  For example, 
.RS
.IP
\fCset maxhits 100\fP
.RE
.IP
halts \fBfind\fP after a total of 100 matches have been found.
.TP
.B maxhitspm
Across all the anonymous FTP archives on the Internet (and even on one single
anonymous FTP archive) many files will have the same name. For example, if you
search for a very common filename like `README' you can get hundreds, even
thousands of matches. You can limit the number of files with the same name
through this variable. For example,
.RS
.IP
\fCset maxhitspm 100\fP
.RE
.IP
tells the system to list only 100 files with the same name. Note that the
overall maximum number of files returned is still controlled by the
\fBmaxhits\fP variable.
.TP
.B maxmatch
This variable will limit the number filenames returned. For example, if
maxmatch is set to 2 and you perform a substring search for the string `etc',
and the catalog contains filenames `etca', `betc' and `detc' only the
filenames `etca' and `betc' will be returned. However, depending on the values
of maxhitspm and maxhits you will get back a number of actual files with those
names.
.IP
Example:
.RS
.IP
\fCset maxmatch 20\fP
.RE
.IP
.TP
.B max_split_size
Approximate maximum size, in bytes, of a file to be mailed to the user.  Any
output larger than this will be split into pieces of about this size.  This
can be set by the user, in the range 1024 to ~2Gb, with a default of 51200
bytes.
.SS "String Variables"
.TP
.B compress
The kind of data compression the user can specify when mailing back output.
Currently allowed values are `none' and `compress' (standard UNIX
.BR compress (1),
with a default of `none'.
.TP
.B encode
The type of post-compression encoding the user can specify when mailing back
output.  Currently allowed values are `none' and `uuencode', with a
default of `none'. Note that this variable is ignored unless compression
is enabled (via the \fBcompress\fP variable).
.TP
.B language
Allows the user to specify the language in which help, etc. is presented.
Currently the default value is `english'.
.TP
.B mailto
If the \fBmail\fP command is issued with no arguments, mail the output of the
last command to the address specified by this string variable. Initially this
variable is unset.
.IP
Example:
.RS
.IP
\fCset mailto user@frobozz.com\fP
.RE
.IP
Conventional Internet addressing styles are understood.  BITNET sites should
use the convention:
.RS
.IP
\fCuser@sitename.bitnet\fP
.RE
.IP
UUCP addresses can be specified as
.RS
.IP
\fCuser@sitename.uucp\fP
.RE
.TP
.B match_domain
This variable allows users to restrict the scope of their search based upon
the Fully Qualified Domain Names (FQDN) of the anonymous FTP sites being
searched. In this way, the user can specify a colon-separated list of domain
names which all returned sites must match. Each component in the list is
taken as the \fIrightmost\fP part of the FQDN. For example,
.RS
.IP
\fCset match_domain ca:internic.net:harvard.edu\fP
.RE
.IP
means that the names of all returned sites must end in `ca' (Canada),
`internic.net' (sites in the Internet NIC) or `harvard.edu' (sites at
Harvard University).

While these are all real domain names, listing all possible combinations for
say, the USA, would quickly become tedious (and if you think that is bad, try
listing all the countries on the Internet in Europe). To aid in this problem,
the Archie system has the concept of \fIpseudo-domains\fP to allow users to
use a shorthand notation when using this facility. These pseudo-domains are
defined on a server-by-server basis, and you can use the \fIdomains\fP
command to query your current server for its list of predefined
pseudo-domains.

A pseudo-domain is a list of real DNS domain names and/or a list of other
pseudo-domains. For example, the Archie administrator on the server could
define the pseudo-domain
.RS
.IP
\fCusa\fP
.sp
to be
.sp
\fCedu:mil:com:gov:us\fP
.RE
.IP
If this definition existed on the server, then you could 
.RS
.IP
\fCset match_domain usa\fP
.RE
.IP
which would be the same as saying 
.RS
.IP
\fCset match_domain edu:mil:com:gov:us\fP
.RE
.IP
In addition, the server administrator may define
.RS
.IP
\fCnorthamerica\fP
.sp
to be 
.sp
\fCusa:ca:mx\fP
.RE
.IP
meaning that `northamerica' is composed of the pseudo-domain `usa' and
the real domains `ca' (Canada) and `mx' (Mexico). This process can be
repeated for 20 levels (more than sufficient for any naming scheme). By using
the \fBdomains\fP command you can determine which pseudo-domains your current
server supports.
.TP
.B match_path
Sometimes you only would like your search (using the \fBfind\fP command) to
look for files or directories with a certain set of names in their full path.

For example, many anonymous FTP site administrators will put software packages
for the MacIntosh in a path containing the name `mac' or `macintosh'. Another
example is when a document exists in several formats and you are only looking
for the PostScript version. You can guess that the file may end in `.ps' or it
may be in a directory called `ps' or `PostScript'.

This is usually guesswork, but is is useful to have the Archie system only
look for files or directories with particular components in their path name.

This variable allows you to do this. The arguments are a colon-separated list
of possible path name components. In the last example above, saying
.RS
.IP
\fCset match_path ps:postscript\fP
.RE
.IP
will restrict the search only to match those files or directories which have
the strings `ps' or `postscript' in their path.

The comparison is \fIalways\fP case-insensitive (regardless of the value of
the \fBmatch\fP variable) and there is a logical OR connecting the components
so that the above statement says: ``find only files which have `ps' OR
`postscript' in their path''. If either component matches then the condition
is satisfied.
.TP
.B output_format
Select the way the output of find and list is displayed.  It is user settable,
with valid values of `machine' (machine readable format), `terse' and
`verbose', with a default of `verbose'.
.TP
.B search
The type of search done by the \fBfind\fP (or \fBprog\fP) command.  It is user
settable with a range of `exact', `regex', `sub', `subcase',
`exact_regex', `exact_sub' and `exact_subcase', with a default of
`sub'.  (The `exact_\fI<x>\fP' types cause it to try `exact' first, then
fall back to type \fI<x>\fP if no matches are found).  The values have the
following meanings:
.RS
.TP
.B exact
Exact match (the fastest method).  A match occurs if the file (or directory)
name in the catalog corresponds \fIexactly\fP to the user-specified substring
(including case).
.IP
For example, this type of search could be used to locate all files called
`xlock.tar.Z'.
.TP
.B regex
Allow user-specified (search) strings to take the form of
.BR ed (1)
regular expressions.
.IP
Note: unless specifically anchored to the beginning (with `^') or end
(with `$') of a line,
.BR ed (1)
regular expressions (effectively) have `.*' prepended and appended to them.
For example, it is not necessary to type
.RS
.IP
\fCfind .*xnlock.*\fP
.RE
.IP
because
.RS
.IP
\fCfind xnlock\fP
.RE
.IP
suffices.  In this instance, the
.B regex
match is equivalent to a simple substring match.  Those unfamiliar with
regular expressions should refer to the section entitled
.SM "REGULAR EXPRESSIONS"
which appears below.
.TP
.B sub
Substring (case insensitive).  A match occurs if the file (or directory) name
in the catalog contains the user-specified substring, without regard to case.
For example, the pattern
.RS
.IP
\fCis\fP
.RE
.IP
matches any of the following:
.RS
.IP
\fCislington
.br
this
.br
poison\fP
.RE
.TP
.B subcase
Substring (case sensitive).  As above, but case is significant.  For example,
the pattern
.RS
.IP
\fCTeX\fP
.RE
.IP
will match
.RS
.IP
\fCLaTeX\fP
.RE
.IP
but neither of the following:
.RS
.IP
\fCLatex
.br
TExTroff\fP
.RE
.TP
.B server
the Prospero server to which the client connects when \fBfind\fP or \fBlist\fP
commands are invoked.  It is user settable, with a default value of
`localhost'.
.TP
.B sortby
Set the method of sorting to be applied to output from the \fBfind\fP command.
Typing the keyboard interrupt character (generally Cntl-C on UNIX hosts)
aborts a search. This will also dequeue the request from the server.  Unlike
previous versions of the Archie system, version 3 does not allow partial
results.  The output phase may be aborted by typing the abort character a
second time.  The five permitted methods (and their associated reverse orders)
are:
.RS
.TP
.B none
Unsorted (default; no reverse order, although
.B rnone
is accepted)
.TP
.B filename
Sort files and directories by name, using lexical order (reverse order:
.BR rfilename )
.TP
.B hostname
Sort on the archive host name, in lexical order (reverse order:
.BR rhostname )
.TP
.B size
Sort by size, largest files and directories first (reverse order:
.BR rsize )
.TP
.B time
Sort by modification time, with the most recent file and directory names first
(reverse order:
.BR rtime )
.RE
.SH "THE INTERACTIVE (TELNET) INTERFACE"
The interactive interface accepts the following commands and variables in
addtion to those listed above.
.SS Commands
.TP
.BR stty " [[\fI<option>\fP \fI<character>\fP] ...]"
This command allows the user to change the interpretation of specified
characters, in order to match their particular terminal type.  At the moment
only `erase' is recognized as an \fI<option>\fP.  (Typically,
\fI<character>\fP is a control character and may be specified as a pair of
characters (e.g. control-h as `^' followed by `h'), the character
itself (literal), or as a quoted pair or literal.
.sp
Without any arguments the command displays the current values of the
recognized options.
.TP
.BR mail " [\fI<address>\fP]"
The output of the previous successful command (i.e. an invocation of
\fBfind\fP or \fBlist\fP that produced output) is mailed to the specified
electronic mail address. If no \fI<address>\fP is given the contents of the
\fBmailto\fP variable are used. If this variable is not set then an error
occurs, and nothing is mailed, although the output is still available to be
mailed.
.IP
Example:
.RS
.IP
\fCmail user1@hello.edu\fP
.RE
.IP
Conventional Internet addressing styles are understood.  BITNET sites should
use the convention:
.RS
.IP
\fCuser@sitename.bitnet\fP
.RE
.IP
UUCP addresses can be specified as
.RS
.IP
\fCuser@sitename.uucp\fP
.RE
.TP
.B pager
This command is included only for backward compatibility.  It has the same
effect as `set pager'.  Its use is discouraged and it will be removed in a
future release.
.TP
.B nopager
This command is included only for backward compatibility.  It has the same
effect as `unset pager'.  Its use is discouraged and it will be removed in
a future release.
.SS Variables
.TP
.B autologout
Set the length of idle time (in minutes) allowed before automatic logout.  The
permissible range is between 1 and 300.  The default value is 60.  For example,
.RS
.IP
\fCset autologout 45\fP
.RE
.IP
logs the user out after 45 minutes of idle time.
.TP
.B pager
Filter all output through the default pager.  By default this variable is
unset.  When using the pager you may also want to set the \fBterm\fP variable
to your terminal type (see the \fBterm\fP variable).
.IP
Example:
.RS
.IP
\fCset pager\fP
.RE
.TP
.B status
When set, this variable will cause the system to report the position in the
queue of your request on the server. In addition, it will display the
\fIestimated\fP time to completion of your request. This estimate is based in
an average of the amount of times similar queries have taken in the past
several minutes. The variable also controls the display of a \fIspinner\fP
during the catalog search, which indicates that we are awaiting results from
the Prospero server.  This variable is set by default.
.TP
.B term
Specify the type of terminal in use (and optionally, its size in rows and
columns).  This information is used by the pager.
.IP
The usage is:
.RS
.IP
\fCset term \fI<terminal-type>\fP [\fI<#rows>\fP [\fI<#columns>\fP]]\fP
.RE
.IP
The terminal type is mandatory, but the number of rows and columns is
optional; specify either rows only, or both rows and columns.  The default
value for this variable is `dumb', with 24 rows and 80 columns. However it
may be set automatically through the \fBtelnet\fP protocol negotiation.
.IP
Examples:
.RS
.IP
\fCset term vt100
.br
set term xterm 60
.br
set term xterm 24 100\fP
.SH "THE EMAIL INTERFACE"
The Archie email interface currently accepts the following commands in
addition to those listed in the
.SM COMMANDS
section above.
.PP 
.BI path " <address>"
is an alias for
.IP
\fCset mailto\fP \fI<address>\fP
.TP
.B quit
Ignore any further lines past this point in the mail. This is generally not
needed, but can be used to prevent the system from interpreting extra text,
such as signatures, as Archie commands.
.RE
.sp
The `Subject:' line in incoming mail is processed as if it were part of the
main message body.
.sp
A message not containing a valid request will be treated as a \fBhelp\fP
request.
.SH "REGULAR EXPRESSIONS"
Regular expressions follow the conventions of the
.BR ed (1)
command, allowing sophisticated pattern matching.  In the following
discussion, the string containing a regular expression will be called the
\fIpattern\fP, and the string against which it is to be matched is called the
\fIreference string\fP.  Regular expressions imbue certain characters with
special meaning, providing a quoting mechanism to remove this special meaning
when required.
.LP
The rules governing regular expression are:
.TP
.B c
A character
.B c
matches itself unless it has been assigned a special meaning as listed below.
A special character loses its special meaning when preceded by the backslash
character (`\e').  The exception to this rule is the opening brace
(`{'), which \fIis\fP special when preceded by a backslash.  Thus,
although `*' normally has special meaning, the string `\e*'
matches itself.  For example, the pattern
.RS
.IP
\fCacdef\fP
.RE
.IP
matches any of the following:
.RS
.IP
\fCs83acdeffff
.br
acdefsecs
.br
acdefsecs\fP
.RE
.IP
but neither of the following:
.RS
.IP
\fCaccdef
.br
aacde1f\fP
.RE
.IP
Example:
.IP
Normally the characters `*'  and `$' are special, but the pattern
.RS
.IP
\fCa\\*bse\\$\fP
.RE
.IP
acts as above.  Any reference string containing
.RS
.IP
\fCa*bse$\fP
.RE
.IP
as a substring will be flagged as a match.
.TP
.B \&.
A period (known as a \fIwildcard\fP character) matches any character except
the newline.  For example, the pattern
.RS
.IP
\&\fC....\fP
.RE
.IP
will match any 4 characters in the reference string, except a newline
character.
.TP
.B ^
A caret (`^') appearing at the beginning of a pattern requires that the
reference string must \fIstart\fP with the specified pattern (an escaped
caret, or a caret appearing elsewhere in the pattern, is treated as a
non-special character).  For example, the pattern
.RS
.IP
\fC^efghi\fP
.RE
.IP
The pattern will match only those reference strings starting with `efghi';
thus, it will match either of the following:
.RS
.IP
\fCefghi\fP
.br
\fCefghijlk\fP
.RE
.IP
but not
.RS
.IP
\fCabcefghi\fP
.RE
.TP
.B $
A dollar sign (`$') appearing at the end of a pattern requires that the
pattern appear at the end of a reference string.  An escaped dollar sign, or a
dollar sign appearing elsewhere, is treated as a regular character.  For
example, the pattern
.RS
.IP
\fCefghi$\fP
.RE
.IP
will match either of the following:
.RS
.IP
\fCefghi\fP
\fCabcdefghi\fP
.RE
.IP
but not
.RS
.IP
\fCefghijkl\fP
.RE
.TP
.RI [ <string> ]
Match any single character within the brackets.  The caret (`^') has a
special meaning if it is the first character in the series: the pattern will
match any character \fIother\fP than one in the list.  For example, the
pattern
.RS
.IP
\fC[^abc]\fP
.RE
.IP
will match any character \fIexcept\fP one of
.RS
.IP
\fCa
.br
b
.br
c\fP
.RE
.IP
To match a right bracket (`]') in the list, put it first, as in
.RS
.IP
\fC[]ab01]\fP
.RE
.IP
A caret appearing anywhere but the in first position is treated as a regular
character.
.IP
The dash (`\(em') character is special within square brackets.  It is used
to define a range of ASCII characters to be matched.  For example, the
pattern
.RS
.IP
\fC[a\(emz]\fP
.RE
.IP
matches any lower case letter.  The dash can be made non-special by placing it
first or last within the square brackets.  The characters `$', `*' and `.' are
not special within square brackets.  For example, the pattern
.RS
.IP
\fC[ab01]\fP
.RE
.IP
matches a single occurrence of a character from the set
.RS
.IP
\fCa
.br
b
.br
0
.br
1\fP
.RE
.IP
Example:
.IP
The pattern
.RS
.IP
\fC[^ab01]\fP
.RE
.IP
will match any single character other than one from the set
.RS
.IP
\fCa
.br
b
.br
0
.br
1\fP
.RE
.IP
Example:
.IP
The pattern
.RS
.IP
\fC[a0\(em9b]\fP
.RE
.IP
matches one of the characters
.RS
.IP
\fCa
.br
b\fP
.RE
.IP
or a digit between `0' and `9', inclusive.
.IP
Example:
.IP
The pattern
.RS
.IP
\fC[^a0\(em9b.$]\fP
.RE
.IP
matches any single character which is not in the set
.RS
.IP
\fCa
.br
b
.br
\&.
.br
$\fP
.RE
.IP
or a digit between `0' and `9', inclusive.
.TP
.B *
Match zero or more occurrences of the immediately preceding regular
expression.  For example, the pattern
.RS
.IP
\fCa*\fP
.RE
.IP
matches zero or more occurrences of the character
.RS
.IP
\fCa\fP
.RE
.IP
Example:
.IP
The pattern
.RS
.IP
\fC[A\(emZ]*\fP
.RE
.IP
matches zero or more occurrences of a capital letter.
.TP
.BI \e{ m \e}
Match exactly \fIm\fP occurrences of a preceding regular expression, where
\fIm\fP is a non-negative integer between 0 and 255 (inclusive).  For example,
the pattern
.RS
.IP
\fCab\\{3\\}\fP
.RE
.IP
matches any substring in the reference string consisting of the character
`a' followed by exactly three `b' characters.
.TP
.BI \e{ m ,\e}
Match at least \fIm\fP occurrences of the preceding regular expression.  For
example, the pattern
.RS
.IP
\fCab\\{3,\\}\fP
.RE
.IP
matches any substring, in the reference string, of the character `a'
followed by at least three `b' characters.
.TP
.BI \e{ m , n \e}
Match between \fIm\fP and \fIn\fP occurrences of the preceding regular
expression (where \fIn\fP is a non-negative integer between 0 and 255, and
.IR n > m ).
For example, the pattern
.RS
.IP
\fCab\\{3,5\\}\fP
.RE
.IP
matches any substring, in the reference string, consisting of the character
`a' followed by at least three, but at most five, `b' characters.
.SS "Tips for Using Regular Expressions"
.TP
1)
When matching a substring it is not necessary to use the wildcard character
to match the part of the reference string preceding and following the
substring.  For example, the pattern
.RS
.IP
\fCabcd\fP
.RE
.IP
will match any reference string containing this pattern.  It is not necessary
to use
.RS
.IP
\fC\&.*abcd.*\fP
.RE
.IP
as the pattern.
.TP
2)
In order to constrain a pattern to the entire reference string, use the
construction
.RS
.IP
\fC^\fI<pattern>\fP$\fP
.RE
.TP
3)
The `[]' operator provides an easy mechanism to obtain case
insensitivity.  For example, to match the word
.RS
.IP
\fChello\fP
.RE
.IP
regardless of case, use the pattern
.RS
.IP
\fC[Hh][Ee][Ll][Ll][Oo]\fP
.RE
.SH "THE ARCHIE DATABASE"
The Archie catalog subsystem maintains a list of about 1200 Internet anonymous
.BR ftp (1)
archive sites of approximately 2.5 million \fIunique\fP filenames, themselves
containing 200 Gigabytes (that is, 200,000,000,000 bytes) of information. The
current catalog requires about 400 MB of disk storage.
.SH "SEE ALSO"
bitftp (1L),
ftp(1),
telnet(1),
archie(1),
xarchie(1)
.SH AUTHORS
Bunyip Information Systems.
.br
Montr\o"\'e"al, Qu\o"\'e"bec, Canada
.br
archie-group@bunyip.com
.sp
Archie is a registered trademark of Bunyip Information Systems Inc., Canada,
1990.
.sp
Original manual page by R. P. C. Rodgers,
UCSF School of Pharmacy, San Francisco,
California 94143 (rodgers@maxwell.mmwb.ucsf.edu),
Nelson H. F. Beebe (beebe@math.utah.edu),
and Alan Emtage (bajan@bunyip.com).
Partial funding contributed by Trevor Hales (hales@mel.dit.cicsiro.au)
.\" end of file