glimpse.1

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.TH GLIMPSE l "November 10, 1997"
.SH NAME
\fIglimpse 4.1\fP - search quickly through entire file systems
.SH OVERVIEW
\fIGlimpse\fP (which stands for GLobal IMPlicit SEarch)
is a very popular UNIX indexing and query system that allows 
you to search through a large set of files very quickly.
Glimpse supports most of \fIagrep\fP's options
(\fIagrep\fP is our powerful version of \fIgrep\fP)
including approximate matching (e.g., finding misspelled words),
Boolean queries, and even some limited forms of regular expressions.
It is used in the same way, except that you don't have to
specify file names.
So, if you are looking for a \fIneedle\fP
anywhere in your file system, all you have to do is say
\fIglimpse needle\fR
and all lines containing \fIneedle\fP will appear preceded
by the file name.
.LP
To use glimpse you first need to index your files with glimpseindex.
For example, \fIglimpseindex -o ~\fR  will index everything at or below
your home directory.  See man glimpseindex for more details.
.LP
Glimpse is also available for web sites, 
as a set of tools called \fIWebGlimpse\fP.
(The old glimpseHTTP is no longer supported and is not recommended.)
See http://glimpse.cs.arizona.edu/webglimpse/ for more
information.
.LP
Glimpse includes all of agrep and can be used instead of agrep
by giving a file name(s) at the end of the command.
This will cause glimpse to ignore the index and run agrep as usual.
For example, \fIglimpse -1 pattern file\fR is the same as \fIagrep -1
pattern file\fR.
Agrep is distributed as a self-contained package within glimpse,
and can be used separately.
We added a new option to agrep:  -r searches recursively the
directory and everything below it (see agrep options below);
it is used only when glimpse reverts to agrep.
.LP
Mail [e-mail] to be added to the glimpse mailing list.
Mail [e-mail] to report bugs, ask questions, discuss tricks
for using glimpse, etc. (this is a moderated mailing list with very little
traffic, mostly announcements).
HTML version of these manual pages
can be found in
http://glimpse.cs.arizona.edu/glimpsehelp.html
Also, see the glimpse home pages in
http://glimpse.cs.arizona.edu/
.SH SYNOPSIS
.B glimpse
\- [almost all letters]
.I pattern
.SH INTRODUCTION
We start with simple ways to use glimpse and describe all the
options in detail later on.
Once an index is built, using glimpseindex,
searching for \fIpattern\fP is as easy as saying
.LP
\fIglimpse pattern\fR
.LP
The output of glimpse is similar to that of \fIagrep\fP (or any other
grep).
The pattern can be any agrep legal pattern including a regular
expression or a Boolean query (e.g., searching for Tucson AND Arizona
is done by \fIglimpse 'Tucson;Arizona'\fR).
.LP
The speed of glimpse depends mainly on the number and sizes
of the files that
contain a match and only to a second degree on the total size of all
indexed files.  If the pattern is reasonably uncommon, then all
matches will be reported in a few seconds even if the indexed files
total 500MB or more.  Some information on how glimpse works and a
reference to a detailed article are given below.
.LP
Most of agrep (and other grep's) options are supported, including
approximate matching.  For example,
.LP
\fIglimpse -1 'Tuson;Arezona'\fR
.LP
will output all lines containing both patterns allowing
one spelling error in any of the patterns
(either insertion, deletion, or
substitution), which in this case is definitely needed.
.LP
\fIglimpse -w -i 'parent'\fR
.LP
specifies case insensitive (\-i) and match on complete words (\-w).
So 'Parent' and 'PARENT' will match, 'parent/child' will match,
but 'parenthesis' or 'parents' will not match.
(Starting at version 3.0, glimpse can be much faster when these
two options are specified, especially for very large indexes.
You may want to set an alias especially for "glimpse -w -i".)
.LP
The -F option provides a pattern that must match the file name.
For example,
.LP
\fIglimpse -F '\\.c$' needle\fR
.LP
will find the pattern \fIneedle\fP in all files whose name
ends with .c.
(Glimpse will first check its index to determine which files may
contain the pattern and then run agrep on the file names to further
limit the search.)
The -F option \fIshould not\fR be put at the end after the main pattern
(e.g., "glimpse needle -F hay" is incorrect).
.SH "A Detailed Description of All the Options of Glimpse"
.TP
.B \-\fI#\fP
\fI#\fP is an integer between 1 and 8
specifying the maximum number of errors
permitted in finding the approximate matches (the default is zero).
Generally, each insertion, deletion, or substitution counts as one error.
It is possible to adjust the relative cost of insertions,
deletions and substitutions (see -I -D and -S options).
Since the index stores only lower case characters, errors of
substituting upper case with lower case may be missed
(see LIMITATIONS).
Allowing errors in the match requires more time and can slow down
the match by a factor of 2-4.
Be very careful when specifying more than one error, as the number
of matches tend to grow very quickly.
.TP
.B \-a
prints attribute names.  This option applies only to Harvest SOIF structured
data (used with glimpseindex -s).
(See http://harvest.transarc.com for more information
about the Harvest project.)
.TP
.B \-A
used for glimpse internals.
.TP
.B \-b
prints the byte offset (from the beginning of the file)
of the end of each match.
The first character in a file has offset 0.
.TP
.B \-B
Best match mode.  (Warning: -B sometimes misses matches.  It is safer
to specify the number of errors explicitly.)
When \-B is specified and no exact matches are found, glimpse
will continue to search until the closest matches (i.e., the ones
with minimum number of errors)
are found, at which point the following message will be shown:
"the best match contains x errors, there are y matches, output them? (y/n)"
This message refers to the number of matches found in the index.
There may be many more matches in the actual text (or there may be none
if -F is used to filter files).
When the \-#, \-c, or \-l options are specified, the \-B option is ignored.
In general, \-B may be slower than \-#, but not by very much.
Since the index stores only lower case characters, errors of
substituting upper case with lower case may be missed
(see LIMITATIONS).
.TP
.B \-c
Display only the count of matching records.  Only files with count > 0
are displayed.
.TP
.B \-C
tells glimpse to send its queries to \fIglimpseserver\fP.
.TP
.B \-d "'\fIdelim\fP'"
Define \fIdelim\fP to be the separator between two records.
The default value is '$', namely a record is by default
a line.
\fIdelim\fP can be a string of size at most 8
(with possible use of ^ and $), but not
a regular expression.
Text between two \fIdelim\fP's, before the first \fIdelim\fP,
and after the last \fIdelim\fP is considered as one record.
For example, -d '$$' defines paragraphs as records and -d '^From\ '
defines mail messages as records.
\fIglimpse\fP matches each record separately.
\fBThis option does not currently work with regular expressions.\fP
The -d option is especially useful for Boolean AND queries,
because the patterns need not appear in the same line but in the
same record. 
For example, 
\fIglimpse -F mail -d '^From\ ' 'glimpse;arizona;announcement'\fR
will output all mail messages (in their entirety) that have
the 3 patterns anywhere in the message (or the header),
assuming that files with 'mail' in their name contain mail
messages.
If you want the scope of the record to be the whole file,
use the -W option.
\fBGlimpse warning\fP:
Use this option with care.  If the delimiter is set to
match mail messages, for example, and glimpse finds the pattern 
in a regular file, it may not find the delimiter and will 
therefore output the whole file.
(The -t option - see below - can be used to put the \fIdelim\fP at
the end of the record.)
\fBPerformance Note:\fP
Agrep (and glimpse) resorts to more complex search when the \-d
option is used.  The search is slower and unfortunately no more than
32 characters can be used in the pattern.
.TP
.B \-D\fIk\fP
Set the cost of a deletion to \fIk\fP (\fIk\fP is a positive integer).
This option does not currently work with regular expressions.
.TP
.BI \-e " pattern"
Same as a simple
.I pattern
argument, but useful when the
.I pattern
begins with a
.RB ` \- '.
.TP
.B \-E
prints the lines in the index (as they appear in the index)
which match the pattern.  Used mostly for debugging and 
maintenance of the index.
This is not an option that a user needs to know about.
.TP
.B \-f  \fIfile_name\fR
this option has a different meaning for agrep than for glimpse:
In glimpse, only the files whose names are
listed in \fIfile_name\fP are matched.
(The file names have to appear as in .glimpse_filenames.)
In agrep, the file_name contains the list of the patterns that are searched.
(Starting at version 3.6, this option for glimpse is much faster
for large files.)
.TP
.B \-F  \fIfile_pattern\fR
limits the search to those files whose name (including the whole
path) matches \fIfile_pattern\fP.
This option can be used in a variety of applications to provide
limited search even for one large index.
If \fIfile_pattern\fP matches a directory, then all files with this directory on
their path will be considered.  To limit the search to actual file
names, use $ at the end of the pattern.  \fIfile_pattern\fP can be a
regular expression and even a Boolean pattern.
This option is implemented by running agrep \fIfile_pattern\fP on the 
list of file names obtained from the index.  Therefore, searching the
index itself takes the same amount of time, but limiting the
second phase of the search to only a few files can speed up the
search significantly.
For example,
.sp 1
glimpse -F 'src#\\.c$' needle
.sp 1
will search for needle in all .c files with src somewhere along the
path.
The -F \fIfile_pattern\fP must appear before the search pattern
(e.g., glimpse needle -F '\\.c$' will not work).
It is possible to use some of agrep's options when 
matching file names.  In this case all options as well as the
file_pattern should be in quotes.  (-B and -v do not work very well
as part of a file_pattern.)
For example,
.sp 
glimpse -F '-1 \\.html' pattern
.sp
will allow one spelling error when matching .html to the file names
(so ".htm" and ".shtml" will match as well).
.sp
glimpse -F '-v \\.c$' counter
.sp
will search for 'counter' in all files \fIexcept\fP for .c files.
.TP
.B \-g
prints the file number (its position in the .glimpse_filenames
file) rather than its name.
.TP
.B \-G
Output the (whole) files that contain a match.
.TP
.B \-h
Do not display filenames.
.TP
.B \-H  \fIdirectory_name\fR
searches for the index and the other .glimpse files in
\fIdirectory_name\fP.  The default is the home directory.
This option is useful, for example, if several different indexes are 
maintained for different archives (e.g., one for mail messages, one
for source code, one for articles).
.TP
.B \-i
Case-insensitive search \(em e.g., "A" and "a" are considered equivalent.
Glimpse's index stores all patterns in lower case (see LIMITATIONS below).
\fBPerformance Note:\fP
When \-i is used together with the \-w option, 
the search may become much faster.
It is recommended to have \-i and \-w as defaults, for example,
through an alias.  We use the following alias in our .cshrc file
.br
alias glwi 'glimpse -w -i'
.TP
.B \-I\fIk\fP
Set the cost of an insertion to \fIk\fP (\fIk\fP is a positive integer).
This option does not currently work with regular expressions.
.TP
.B \-j 
If the index was constructed with the -t option, then \-j 
will output the files last modification dates in addition to
everything else.
There are no major performance penalties for this option.
.TP
.B \-J \fIhost_name\fP
used in conjunction with glimpseserver (\-C) to connect to 
one particular server.
.TP
.B \-k
No symbol in the pattern is treated as a meta character. 
For example, glimpse -k 'a(b|c)*d' will find  
the occurrences of a(b|c)*d whereas glimpse 'a(b|c)*d' 
will find substrings that match the regular expression 'a(b|c)*d'.
(The only exception is ^ at the beginning of the pattern and $ at the
end of the pattern, which are still interpreted in the usual way.  
Use \\^ or \\$ if you need them verbatim.)
.TP
.B \-K \fIport_number\fP
used in conjunction with glimpseserver (\-C) to connect to 
one particular server at the specified TCP port number.
.TP
.B \-l
Output only the files names that contain a match.
This option differs from the \-N option in that the files
themselves \fIare\fP searched, but the matching lines are
not shown.