Blank lines, or lines consisting entirely of whitespace, are ignored.

Comments start with the CW# character and continue up to and including the end of the line. While leading whitespace is permitted, comments are treated as such only if they are on lines by themselves.

Variable definition lines are of the form: variable_name argument(s) where variable_name is a member of one of the types described in the remaining sections, and argument(s) are specific to every variable name. For variable_name, case is irrelevant.

Variables of this type take one argument that must be one of: CWf, CWfalse, CWn, CWno, CWoff, CWon, CWt, CWtrue, CWy, or CWyes. Case is irrelevant. Variables of this type are: AssociateMeta, ExtractFilter, FollowLinks, Incremental, RecurseSubdirs, SearchBackground, and StemWords.

Variables of this type are just like string variables (see below) except that the argument must be one of a set of pre-determined values. Case is irrelevant. Variables of this type are: ResultsFormat and SearchDaemon. ResultsFormat must be either: CWclassic or CWXML. SearchDaemon must be one of: CWnone, CWtcp, CWunix, or CWboth.

Variables of this type are of the form: pattern command where pattern is a shell pattern (regular expression) and command is the command-line to execute the filter.

Within a command, there are a few CW% substitutions that are done at run-time:

b

Basename of filename.

B

Basename minus last extension.

e

Extension of filename.

E

Second-to-last extension of filename.

f

Entire filename.

F

Filename minus last extension.

That is: the CW% and one character immediately after it are substituted as described in the above table. Substituted filenames are skipped past and not rescanned for more substitutions, but the remainder of the command is. To use a literal CW% or CW@, simply double it. (For more on filter variables, see FILTERS below.)

Variables of this type are: FilterAttachment and FilterFile.

Variables of this type take one numeric argument. A special string of CWinfinity is taken to mean ``the largest possible integer value.'' Case is irrelevant. Variables of this type are: FilesReserve, ResultsMax, SocketQueueSize, SocketTimeout, ThreadsMax, ThreadsMin, ThreadTimeout, TitleLines, Verbosity, WordFilesMax, WordPercentMax, and WordThreshold.

For WordThreshold, only the super-user can specify a value larger than the compiled-in default.

Variables of this type are like integer variables except that if an optional trailing percent sign (CW%) is present, the value is taken to be a percentage rather than an absolute number. Variables of this type are: FilesGrow.

Variables of this type take one argument that is the remainder of the line minus leading and trailing whitespace. To preserve whitespace, surround the argument in either single or double quotes. The quotes themselves are stripped from the argument, but only if they match. Variables of this type are: ExtractExtension, Group, IndexFile, PidFile, ResultSeparator, SocketFile, StopWordFile, TempDirectory, and User.

Variables of this type take one or more arguments separated by whitespace. Variables of this type are: ExcludeClass, ExcludeFile, ExtractFile, and ExcludeMeta.

Variables of this type are: IncludeFile, IncludeMeta, and SocketAddress.

An IncludeFile configuration file line is of the form: module_name pattern ... where module_name is the name of the module (case is irrelevant) to handle the indexing of the filename patterns that follow. Module names are: CWtext (plain text), CWHTML (HTML and XHTML), CWMail (mail and news messages), CWMan (Unix manual pages), and CWRTF (Rich Text Format).

An IncludeMeta configuration file line is of the form: name[=new_name] ... It is like a set variable except arguments may optionally be followed by reassignments. For example, a value of: adr=address says to include and index the words associated with the meta name CWadr, but to store the name as CWaddress in the generated index file so that queries would use CWaddress rather than CWadr.

A SocketAddress configuration file line is of the form: [ host : ] port that is: an optional host and colon followed by a port number. The host may be one of a host name, an IPv4 address (in dot-decimal notation), an IPv6 address (in colon notation) if supported by the operating system, or the CW* character meaning ``any IP address.'' Omitting the host and colon also means ``any IP address.''

Via the FilterFile configuration file variable, files matching patterns can be filtered prior to indexing or extraction. For example, to uncompress CWbzip2'd, CWgzip'd, and CWcompress'd files prior to indexing or extraction, the FilterFile variable lines in a configuration file would be: FilterFile *.bz2 bunzip2 -c %f > @%F FilterFile *.gz gunzip -c %f > @%F FilterFile *.Z uncompress -c %f > @%F Given that, a filename such as CWfoo.txt.gz would become CWfoo.txt. If files having CWtxt extensions should be indexed, then it will be. Note that the command on the FilterFile line must not simply be: gunzip @%f # WRONG! because CWgunzip will replace the compressed file with the uncompressed one.

Here's an example to convert PDF to plain text for indexing using the xpdf(1) package's CWpdftotext command: FilterFile *.pdf pdftotext %f @%F.txt A file can be filtered more than once prior to indexing or extraction, i.e., filters can be ``chained'' together. For example, if the uncompression and PDF examples shown above are used together, compressed PDF files will also be indexed or extracted, i.e., filenames ending with one of CW.pdf.bz2, CW.pdf.gz, or CW.pdf.Z double extensions.

Note, however, that just because a filename has an extension for which a filter has been specified does not mean that a file will be filtered and subsequently indexed or extracted. When index++ or extract++ encounters a file having an extension for which a filter has been specified, it performs the filename substitution(s) on it first to determine what the target filename would be. If the extension of that filename should be indexed or extracted (because it is among the set of extensions specified with either the -e or --pattern options or the IncludeFile variable or is not among the set specified with either the -E or --no-pattern options or the ExcludeFile variable), then the filter(s) are executed to create it.

Via the FilterAttachment configuration file variable, e-mail attachments whose MIME types match particular patterns can be filtered and thus indexed. An attachment is written to a temporary file by itself (after having been base-64 decoded, if necessary) and a filter command is called on that file.

For example, to convert a PDF attachment to plain text so it can be indexed, the FilterAttachment variable line in a configuration file would be: FilterAttachment application/pdf pdftotext %f @%F.txt MIME types must be specified entirely in lower case. Patterns can be useful for MIME types. For example: FilterAttachment application/*word extract++ -f %f > @%F.txt can be used regardless of whether the MIME type is CWapplication/msword (the official MIME type for Microsoft Word documents) or CWapplication/vnd.ms-word (an older version).

The MIME types that are built into index++(1) are: CWtext/plain, CWtext/enriched (but only if the RTF module is compiled in), CWtext/html (but only if the HTML module is compiled in), CWtext/*vcard, CWmessage/rfc822, CWmultipart/something (where something is one of: CWalternative, CWmixed, or CWparallel). FilterAttachment variable lines can override the handling of the built-in MIME types.

Unlike file filters, attachment filters must convert directly to plain text and can not be ``chained'' together. (This restriction exists because there is no way to know what any intermediate MIME types would be to apply more filters.)