.\" "@(#)invert.1 4.4 9/10/85";
.TH INVERT 1 "28 July 1983"
invert, lookup \(em create and access an inverted index
creates an inverted index to one or more files.
retrieves records from files for which an inverted index exists.
The inverted indices are intended for use with
creates one inverted index to all of its input files.
The index must be stored in the current directory and may not be moved.
Input files may be absolute path names or paths relative to the current
Each input file is viewed as a set of records;
each record consists of non-blank lines;
records are separated by blank lines.
retrieves records based on its input
Each line of input is a retrieval request.
All records that contain all of the keywords in the retrieval request
If there are no matching references, ``No references found.'' is sent to
first searches in the user's private index (default INDEX)
and then, if no references are found,
in the system index (/usr/dict/papers/INDEX).
The system index was produced using
with the default options;
in general, the user is advised to use the defaults.
Keywords are a sequence of non-white space characters
with non-alphanumeric characters removed.
Keywords must be at least two characters and are truncated
Some common words are ignored.
Some lines of input are ignored for the purpose of collecting keywords.
The following options are available for
File contains common words, one per line.
Common words are not used as keys.
(Default /usr/new/lib/bmac/common.)
Maximum number of keys kept per record. (Default 100)
Maximum length of keys. (Default 6)
File is the name of the private index file (output of
The index must be stored in the current directory.
(Be careful of the second form.
The shell will not know to expand the file name.
E.g. \-p~/index won't work; use \-p\ ~/index.)
Ignore lines that begin with %x
for explanation of field names.)
with the same meanings as
option can be followed by a list of comma separated index files.
These are searched in order from left to right until at least one reference
/usr/tmp/invertxxxxxx scratch file for invert
/usr/new/lib/bmac/common default list of common words
/usr/dict/papers/INDEX default system index
\fIA UNIX Bibliographic Database Facility\fP,
Timothy A. Budd and Gary M. Levin,
University of Arizona Technical Report 82-1, 1982.
Messages indicating trouble accessing files are sent on
There is an explicit message on
if no references are found.
produces a one line message of the form,
\*(oq%D\ documents\ \ \ %D distinct\ keys\ \ %D\ key\ occurrences\*(cq.
This can be suppressed with the \-s option.
The message \*(oqlocate: first key (%s) matched too many refs\*(cq
indicates that the first key matched more references than could be stored
The simple solution is to use a less frequently occurring key as the first
No attempt is made to check the compatibility between an index
The user must create a new index whenever
the files that are indexed are modified.
Attempting to invert a file containing unprintable characters can