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WN Utility Programs

The main utility program used by WN is wndex which is used to produce the index.cache files from index.wn files. Its use is described in detail in the section on "Using the wndex Utility" in this guide. In this chapter we consider some other utilities, mostly perl programs, which are useful in maintaining your server.

13.1 wn_mkdigest

wn_mkdigest is a perl program which can be found in the bin directory of the distribution. This program is designed to work with the range feature of the WN server and with list searches. It produces a list of anchors or links to sections of a structured plain text document like an address list or a mail file.

Here is how it works. The wn_mkdigest utility is executed with three (or more) arguments. The first two arguments are regular expressions. The first regular expression should match the section separator of the structured file and the second should match the beginning of the line to be used as the section title. (More about this below.) The next argument is the name of a structured file, like a mail file, news digest or address list. Instead of a single structured file several files can be listed and wn_mkdigest will process their concatenation.

Now more about the regular expressions: Suppose our structured file is a mail file in its usual format with a number of messages. The first regular expression should match just the lines which are the beginning of each section (in this case each message). For a mail file a good choice would be "^From " which matches the word "From" followed by a space at the beginning of a line.

The second regular expression matches start of the line which you would like to be the title of the section. It is convenient to have the link text be everything after the occurrence of the matching pattern for this regular expression. So for the mail file we would choose "^Subject:" for this regular expression. Then the program will produce a list of links one for each message with the text in the anchor the contents of the message Subject line (minus the word "Subject:"). Each link when accessed will produce a plain text document containing just that mail message.

So if our mail file is named foo we should execute the command:

wn_mkdigest "^From " "^Subject:" foo

Note the quotation marks which are needed to get the space after "From". It produces a file named foo.index.html which consists primarily of an unordered list. Each item in the list is an anchor referring to a line range in foo -- the ranges being delimited by lines which match the first regular expression argument. In this case that means each range will start with a line beginning with "From " which is the marker in a mail file designating the start of a new message. The anchor label for each range is taken from the first line in the range which contains a match for the second regular expression and, in fact, as mentioned above, it will consist of everything on that line after the matched regular expression.

The first line of each range or section is a line which matches the first regular expression and the next matching line will begin the next section. Normally the search for the match for the anchor title regular expression begins with this first line. However, it is sometimes useful to skip this first line in the search for a title match. This can be done by starting the second regular expression with the character '$'. For example the command:

wn_mkdigest ^$ $^ foo

is a common one. It says to divide foo into sections (line ranges) which are separated by blank lines (the regular expression '^$' matches a blank line). To obtain an anchor title for each section the blank line is skipped (since the second regular expression starts with '$') and then everything on the next line is taken as the title (since '^' matches the beginning of the next line). The regular expressions of this example would be useful, for example, for an address list foo which consisted of multi-line records separated by blank lines with an individual's name on the first line of each record. The wn_mkdigest utility would then produce a foo.index.html file with an unordered list of anchors, one for each individual in the list. Selecting an anchor would present the record for that individual. Using a list search for this file would allow a form user to enter a name or regular expression and obtain a list of anchors for matching items.

The wn_mkdigest command can have any number of files listed after the regular expressions and it will produce a single file whose name is the name of the first file with ".index.html" appended. This file will contain a list of links to all the sections of all the files given on the command line.

When wn_mkdigest writes the index file (e.g., foo.index.html), it adds two HTML comments to mark the start and end of the lines containing links to the records in your structured document. The markers look like this, where VERSION is the current version of wn_mkdigest:

<!-- Range list generated by wn_mkdigest/VERSION -->

<!-- End of range list generated by wn_mkdigest/VERSION -->

The first time wn_mkdigest writes an index file, it writes a default leader and trailer before and after the link lines. If wn_mkdigest finds an existing index file when it runs, it uses the information preceding the first marker and following the second marker as the leader and trailer for the new index file. This means you can run wn_mkdigest to create the initial index file, then edit the beginning and/or end of the file to modify the leader and trailer. Subsequent invocations of wn_mkdigest will retain your modifications each time the index file is recreated.

If you add the -b argument when you use wn_mkdigest (i.e. run the command "wn_mkdigest -b regexp1 regexp2 foo" then it will produce a file foo.index.html which uses byte ranges rather than the default line ranges. This functions the same except the server will log the number of bytes actually sent when a request is served (the server won't bother to count the bytes in a line range request).

There are fancier tools than wn_mkdigest for displaying mail archives, but this utility has great flexibility for dealing with a wide variety of structured files.

13.2 wnpnuts

PNUTS (pronounced "peanuts") is an acronym for previous, next, up, top, search. wnpnuts is a perl program which takes as argument the name of a file describing the hierarchical structure of a group of HTML files constituting a single virtual document. The wnpnuts program then searches these files for lines which begin with optional whitespace followed by the string:

<!-- pnuts -->

which it replaces with this string followed by a sequence of anchors like:

[previous] [next] [up] [top] [search] [index]

with links to the relevant files in the virtual document. Actually it replaces this line with a single line starting with <!-- pnuts -->, followed by the anchors. That way the next time it is run, say after inserting a new chapter in your document, the <!-- pnuts --> line will be replaced by a new one with the appropriate links.

The wnpnuts program is run with a command like:

wnpnuts -s dosearch.html -i docindex.html foo.pnuts

The argument "-s dosearch.html" is optional and supplies a URL for the "[search]" anchor to be substituted. Thus if just "dosearch.html" is used this will be an anchor linking to a relative URL. Instead you could use a full URL like "http://hostname/dir/file". If there is no '-s' argument then there will be no search item in the list of items inserted by wnpnuts. The optional argument "-i docindex.html" is similar to the '-s' option except it provides the URL (relative or absolute) which should be anchored to "[index]". This URL typically points to an an HTML document created with wnindexmaker.

The file foo.pnuts contains the information by which wnpnuts knows which files to process and what the order of those files should be. It consists of a list of files relative to the current directory, one per line, in the order which should be reflected in the "[next] [previous]" links. If a file is hierarchically one level lower than the previous file this should be indicated by preceding its name with one more "<tab>" character than the preceding file. Here is an example:


If this list is supplied to wnpnuts it will insert anchors into all these files wherever <!-- pnuts --> occurs. All those named [top] will point to the file top.html. In firstsub.html and secondsub.html the [up] link will point to second.html. The [previous] and [next] links will reflect the order top.html, second.html, firstsub.html, subsub.html, secondsub.html, third.html.

13.3 wnindexmaker

This is a perl program whose function is to produce an index (in the usual sense not the WN sense) for a virtual document consisting of a number of HTML files in a single directory. The index to this guide is a good example of how an index produced by wnindexmaker works.

The wnindexmaker program is run with a command like:

wnindexmaker -d path -t "Index Title" -o outputfile words

Here the -d, -t and -o arguments are optional. The -t option supplies the title for the HTML document produced. If no -t argument is given then "Index" is used as the title. The -o option provides a name for the output HTML file -- the default being docindex.html.

The -d option should be the directory containing the files being indexed. It should either begin with a '/' and be relative to the WN root directory or not begin with a '/' and be relative to the directory which will contain the docindex.html file. If there is no -d option then the docindex.html file must reside in the same directory as the files being indexed. If this is done then it is a good idea to add an Attributes=nosearch to the docindex.html record in the index.wn file for the directory. Otherwise docindex.html will index itself in addition to the other files in the directory.

The final argument to wnindexmaker is the file words. It is a list of words or phrases, in alphabetical order, one per line, which you wish to appear in the index. One way to produce it is to use UNIX utilities to produce a list of all words in the files, then run UNIX sort(1) utility with the options -dfu on it and remove unsuitable words from the list.

What the wnindexmaker program does is produce a long list of anchors, one for each word in the words file. Each word is linked to a context search for itself.

13.4 wn_uncache

wn_uncache is a perl program which reverses the action of wndex. It will convert an index.cache file to an index.wn file. It read from its UNIX stdin(3) stream and writes to its UNIX stdout(3) stream.

Thus when invoked with:

wn_uncache <index.cache >index

it will create a file named "index.wn" (overwriting any other file of that name). This file may not be identical to the original index.wn file used to create index.cache, but when wndex is run on this new index.wn file it should produce an index.cache identical to the one used as input for wn_uncache.

13.5 wnv2c

The perl program wnv2c converts log files produced by the server in the verbose format to files in the common log format handled by most server statistics utilities. It also can extract the entries for each virtual host of a multi-homed server which uses different data roots for different IP addresses or different DNS names:

wnv2c [-v] [-i nickname] <verboselog >commonlog

By default this program reads from the UNIX stdin(3) stream a WN log file produced in the verbose format and writes a non-verbose one in the "common log format" to UNIX stdout(3) stream. With the "-i nickname" option it writes only those entries from the virtual host with specified nickname (e.g. if you have edited the file /wn/vhost.h to contain:

char *
vhostlist[][4] =
    { "realname.com" , "", ROOT_DIR, "nickname0" },
    { "virtual1.com" , "", "/var/data1", "nickname1" },
    { "virtual2.com" , "", "/var/data2", "nickname2" },
    { "another.ip.com", "", "/var/data3", "nickname3" },

then "wnv2c -i nickname2 <logfile >log2" will create log2, the file of log entries for the virtual host with DNS name virtual2.com. If you have used the empty string in place of nicknames in the file wn/vhost.h the virtual hosts are numbered consecutively in the order they are listed, starting with 0. So you would use "wnv2c -i 2 <logfile >log2" to get the log entries for the second virtual host.

Using the "-v" option along with the "-i" option gives the verbose form of log entries for specified virtual host.

13.6 wnredir

The perl program wnredir is a very simple Cache-Module for use with WN. It's function is to automatically redirect requests for documents in one directory to requests for other URL's. If you put:

Cache-module=redir http://host/dir/foo.html

in the index.wn file of a directory then every request for something in that directory will be redirected to a request for http://host/dir/foo.html.

If you put:

Cache-module=redir http://host/dir/

then a request for http://this_host/this_dir/whatever.html will be redirected to http://host/dir/whatever.html. These can be useful if you move the contents of an entire directory.

WN version 2.5.0
Copyright © 1998-2005 John Franks <john@math.northwestern.edu>
licensed under the GNU Free Documentation License
Last modified: Sat June 18 2005
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