Provided by: glimpse_4.18.7-8build1_amd64 
NAME
glimpse - search quickly through entire file systems
OVERVIEW
Glimpse (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 agrep's options
(agrep is our powerful version of grep) 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 needle anywhere in your file
system, all you have to do is say glimpse needle and all lines containing needle will appear preceded by
the file name.
To use glimpse you first need to index your files with glimpseindex. For example, glimpseindex -o ~
will index everything at or below your home directory. See man glimpseindex for more details.
Glimpse is also available for web sites, as a set of tools called WebGlimpse. (The old glimpseHTTP is no
longer supported and is not recommended.) See http://webglimpse.net/ for more information.
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, glimpse -1
pattern file is the same as agrep -1 pattern file. 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.
Mail majordomo@webglimpse.net with SUBSCRIBE wgusers in the body to be added to the Webglimpse users
mailing list. This is now the location where glimpse questions are also discussed. Bugs can be reported
at http://webglimpse.net/bugzilla/ HTML version of these manual pages can be found in
http://webglimpse.net/docs/glimpsehelp.html Also, see the glimpse home pages in
http://webglimpse.net/glimpse
SYNOPSIS
glimpse - [almost all letters] pattern
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 pattern is as easy as saying
glimpse pattern
The output of glimpse is similar to that of agrep (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 glimpse 'Tucson;Arizona').
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.
Most of agrep (and other grep's) options are supported, including approximate matching. For example,
glimpse -1 'Tuson;Arezona'
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.
glimpse -w -i 'parent'
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".)
The -F option provides a pattern that must match the file name. For example,
glimpse -F '\.c$' needle
will find the pattern needle 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 should not be put at the end after the main pattern (e.g., "glimpse needle -F
hay" is incorrect).
A Detailed Description of All the Options of Glimpse
-# # 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.
-a prints attribute names. This option applies only to Harvest SOIF structured data (used with
glimpseindex -s). (See http://harvest.sourceforge.net/ for more information about the Harvest
project.)
-A used for glimpse internals.
-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.
-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).
-c Display only the count of matching records. Only files with count > 0 are displayed.
-C tells glimpse to send its queries to glimpseserver.
-d 'delim'
Define delim to be the separator between two records. The default value is '$', namely a record
is by default a line. delim can be a string of size at most 8 (with possible use of ^ and $), but
not a regular expression. Text between two delim's, before the first delim, and after the last
delim is considered as one record. For example, -d '$$' defines paragraphs as records and -d
'^From ' defines mail messages as records. glimpse matches each record separately. This option
does not currently work with regular expressions. 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, glimpse -F mail -d '^From ' 'glimpse;arizona;announcement' 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. Glimpse warning: 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 delim at the end of the record.) Performance Note: 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.
-Dk Set the cost of a deletion to k (k is a positive integer). This option does not currently work
with regular expressions.
-e pattern
Same as a simple pattern argument, but useful when the pattern begins with a `-'.
-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.
-f file_name
this option has a different meaning for agrep than for glimpse: In glimpse, only the files whose
names are listed in file_name 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.)
-F file_pattern
limits the search to those files whose name (including the whole path) matches file_pattern. This
option can be used in a variety of applications to provide limited search even for one large
index. If file_pattern 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.
file_pattern can be a regular expression and even a Boolean pattern. This option is implemented
by running agrep file_pattern 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,
glimpse -F 'src#\.c$' needle
will search for needle in all .c files with src somewhere along the path. The -F file_pattern
must appear before the search pattern (e.g., glimpse needle -F '\.c$' 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,
glimpse -F '-1 \.html' pattern
will allow one spelling error when matching .html to the file names (so ".htm" and ".shtml" will
match as well).
glimpse -F '-v \.c$' counter
will search for 'counter' in all files except for .c files.
-g prints the file number (its position in the .glimpse_filenames file) rather than its name.
-G Output the (whole) files that contain a match.
-h Do not display filenames.
-H directory_name
searches for the index and the other .glimpse files in directory_name. 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).
-i Case-insensitive search — e.g., "A" and "a" are considered equivalent. Glimpse's index stores all
patterns in lower case (see LIMITATIONS below). Performance Note: 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
alias glwi 'glimpse -w -i'
-Ik Set the cost of an insertion to k (k is a positive integer). This option does not currently work
with regular expressions.
-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.
-J host_name
used in conjunction with glimpseserver (-C) to connect to one particular server.
-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.)
-K port_number
used in conjunction with glimpseserver (-C) to connect to one particular server at the specified
TCP port number.
-l Output only the files names that contain a match. This option differs from the -N option in that
the files themselves are searched, but the matching lines are not shown.
-L x | x:y | x:y:z
if one number is given, it is a limit on the total number of matches. Glimpse outputs only the
first x matches. If -l is used (i.e., only file names are sought), then the limit is on the
number of files; otherwise, the limit is on the number of records. If two numbers are given
(x:y), then y is an added limit on the total number of files. If three numbers are given (x:y:z),
then z is an added limit on the number of matches per file. If any of the x, y, or z is set to 0,
it means to ignore it (in other words 0 = infinity in this case); for example, -L 0:10 will
output all matches to the first 10 files that contain a match. This option is particularly useful
for servers that needs to limit the amount of output provided to clients.
-m used for glimpse internals.
-M used for glimpse internals.
-n Each matching record (line) is prefixed by its record (line) number in the file. Performance
Note: To compute the record/line number, agrep needs to search for all record delimiters (or line
breaks), which can slow down the search.
-N searches only the index (so the search is faster). If -o or -b are used then the result is the
number of files that have a potential match plus a prompt to ask if you want to see the file
names. (If -y is used, then there is no prompt and the names of the files will be shown.) This
could be a way to get the matching file names without even having access to the files themselves.
However, because only the index is searched, some potential matches may not be real matches. In
other words, with -N you will not miss any file but you may get extra files. For example, since
the index stores everything in lower case, a case-sensitive query may match a file that has only a
case-insensitive match. Boolean queries may match a file that has all the keywords but not in the
same line (indexing with -b allows glimpse to figure out whether the keywords are close, but it
cannot figure out from the index whether they are exactly on the same line or in the same record
without looking at the file). If the index was not build with -o or -b, then this option outputs
the number of blocks matching the pattern. This is useful as an indication of how long the search
will take. All files are partitioned into usually 200-250 blocks. The file .glimpse_statistics
contains the total number of blocks (or glimpse -N a will give a pretty good estimate; only blocks
with no occurrences of 'a' will be missed).
-o the opposite of -t: the delimiter is not output at the tail, but at the beginning of the matched
record.
-O the file names are not printed before every matched record; instead, each filename is printed just
once, and all the matched records within it are printed after it.
-p (from version 4.0B1 only) Supports reading compressed set of filenames. The -p option allows you
to utilize compressed `neighborhoods' (sets of filenames) to limit your search, without
uncompressing them. Added mostly for WebGlimpse. The usage is:
"-p filename:X:Y:Z" where "filename" is the file with compressed neighborhoods, X is an offset
into that file (usually 0, must be a multiple of sizeof(int)), Y is the length glimpse must access
from that file (if 0, then whole file; must be a multiple of sizeof(int)), and Z must be 2 (it
indicates that "filename" has the sparse-set representation of compressed neighborhoods: the other
values are for internal use only). Note that any colon ":" in filename must be escaped using a
backslash .
-P used for glimpse internals.
-q prints the offsets of the beginning and end of each matched record. The difference between -q and
-b is that -b prints the offsets of the actual matched string, while -q prints the offsets of the
whole record where the match occurred. The output format is @x{y}, where x is the beginning
offset and y is the end offset.
-Q when used together with -N glimpse not only displays the filename where the match occurs, but the
exact occurrences (offsets) as seen in the index. This option is relevant only if the index was
built with -b; otherwise, the offsets are not available in the index. This option is ignored
when used not with -N.
-r This option is an agrep option and it will be ignored in glimpse, unless glimpse is used with a
file name at the end which makes it run as agrep. If the file name is a directory name, the -r
option will search (recursively) the whole directory and everything below it. (The glimpse index
will not be used.)
-R k defines the maximum size (in bytes) of a record. The maximum value (which is the default) is 48K.
Defining the maximum to be lower than the default may speed up some searches.
-s Work silently, that is, display nothing except error messages. This is useful for checking the
error status.
-Sk Set the cost of a substitution to k (k is a positive integer). This option does not currently
work with regular expressions.
-t Similar to the -d option, except that the delimiter is assumed to appear at the end of the record.
Glimpse will output the record starting from the end of delim to (and including) the next delim.
(See warning for the -d option.)
-T directory
Use directory as a place where temporary files are built. (Glimpse produces some small temporary
files usually in /tmp.) This option is useful mainly in the context of structured queries for the
Harvest project, where the temporary files may be non-trivial, and the /tmp directory may not have
enough space for them.
-U (starting at version 4.0B1) Interprets an index created with the -X or the -U option in
glimpseindex. Useful mostly for WebGlimpse or similar web applications. When glimpse outputs
matches, it will display the filename, the URL, and the title automatically.
-v (This option is an agrep option and it will be ignored in glimpse, unless glimpse is used with a
file name at the end which makes it run as agrep.) Output all records/lines that do not contain a
match. (Glimpse does not support the NOT operator yet.)
-V prints the current version of glimpse.
-w Search for the pattern as a word — i.e., surrounded by non-alphanumeric characters. For example,
glimpse -w car will match car, but not characters and not car10. The non-alphanumeric must
surround the match; they cannot be counted as errors. This option does not work with regular
expressions. Performance Note: When -w is used together with the -i option, the search may become
much faster. The -w will not work with $, ^, and _ (see BUGS below). It is recommended to have
-i and -w as defaults, for example, through an alias. We use the following alias in our .cshrc
file
alias glwi 'glimpse -w -i'
-W The default for Boolean AND queries is that they cover one record (the default for a record is one
line) at a time. For example, glimpse 'good;bad' will output all lines containing both 'good' and
'bad'. The -W option changes the scope of Booleans to be the whole file. Within a file glimpse
will output all matches to any of the patterns. So, glimpse -W 'good;bad' will output all lines
containing 'good' or 'bad', but only in files that contain both patterns. The NOT operator '~'
can be used only with -W. It is described later on. The OR operator is essentially unaffected
(unless it is in combination with the other Boolean operations). For structured queries, the
scope is always the whole attribute or file.
-x The pattern must match the whole line. (This option is translated to -w when the index is
searched and it is used only when the actual text is searched. It is of limited use in glimpse.)
-X (from version 4.0B1 only) Output the names of files that contain a match even if these files have
been deleted since the index was built. Without this option glimpse will simply ignore these
files.
-y Do not prompt. Proceed with the match as if the answer to any prompt is y. Servers (or any other
scripts) using glimpse will probably want to use this option.
-Y k If the index was constructed with the -t option, then -Y x will output only matches to files that
were created or modified within the last x days. There are no major performance penalties for
this option.
-z Allow customizable filtering, using the file .glimpse_filters to perform the programs listed there
for each match. The best example is compress/decompress. If .glimpse_filters include the line
*.Z uncompress <
(separated by tabs) then before indexing any file that matches the pattern "*.Z" (same syntax as
the one for .glimpse_exclude) the command listed is executed first (assuming input is from stdin,
which is why uncompress needs <) and its output (assuming it goes to stdout) is indexed. The file
itself is not changed (i.e., it stays compressed). Then if glimpse -z is used, the same program
is used on these files on the fly. Any program can be used (we run 'exec'). For example, one can
filter out parts of files that should not be indexed. Glimpseindex tries to apply all filters in
.glimpse_filters in the order they are given. For example, if you want to uncompress a file and
then extract some part of it, put the compression command (the example above) first and then
another line that specifies the extraction. Note that this can slow down the search because the
filters need to be run before files are searched. (See also glimpseindex.)
-Z No op. (It's useful for glimpse's internals. Trust us.)
The characters `$', `^', `∗', `[', `]', `^', `|', `(', `)', `!', and `\' can cause unexpected results
when included in the pattern, as these characters are also meaningful to the shell. To avoid these
problems, enclose the entire pattern in single quotes, i.e., 'pattern'. Do not use double quotes (").
PATTERNS
glimpse supports a large variety of patterns, including simple strings, strings with classes of
characters, sets of strings, wild cards, and regular expressions (see LIMITATIONS).
Strings
Strings are any sequence of characters, including the special symbols `^' for beginning of line
and `$' for end of line. The following special characters ( `$', `^', `∗', `[', `^', `|', `(',
`)', `!', and `\' ) as well as the following meta characters special to glimpse (and agrep): `;',
`,', `#', `<', `>', `-', and `.', should be preceded by `\' if they are to be matched as regular
characters. For example, \^abc\\ corresponds to the string ^abc\, whereas ^abc corresponds to the
string abc at the beginning of a line.
Classes of characters
a list of characters inside [] (in order) corresponds to any character from the list. For
example, [a-ho-z] is any character between a and h or between o and z. The symbol `^' inside []
complements the list. For example, [^i-n] denote any character in the character set except
character 'i' to 'n'. The symbol `^' thus has two meanings, but this is consistent with egrep.
The symbol `.' (don't care) stands for any symbol (except for the newline symbol).
Boolean operations
Glimpse supports an `AND' operation denoted by the symbol `;' an `OR' operation denoted by the
symbol `,', a limited version of a 'NOT' operation (starting at version 4.0B1) denoted by the
symbol `~', or any combination. For example, glimpse 'pizza;cheeseburger' will output all lines
containing both patterns. glimpse -F 'gnu;\.c$' 'define;DEFAULT' will output all lines containing
both 'define' and 'DEFAULT' (anywhere in the line, not necessarily in order) in files whose name
contains 'gnu' and ends with .c. glimpse '{political,computer};science' will match 'political
science' or 'science of computers'. The NOT operation works only together with the -W option and
it is generally applies only to the whole file rather to individual records. Its output may
sometimes seem counterintuitive. Use with care. glimpse -W 'fame;~glory' will output all lines
containing 'fame' in all files that contain 'fame' but do not contain 'glory'; This is the most
common use of NOT, and in this case it works as expected. glimpse -W '~{fame;glory}' will be
limited to files that do not contain both words, and will output all lines containing one of them.
Wild cards
The symbol '#' is used to denote a sequence of any number (including 0) of arbitrary characters
(see LIMITATIONS). The symbol # is equivalent to .* in egrep. In fact, .* will work too, because
it is a valid regular expression (see below), but unless this is part of an actual regular
expression, # will work faster. (Currently glimpse is experiencing some problems with #.)
Combination of exact and approximate matching
Any pattern inside angle brackets <> must match the text exactly even if the match is with errors.
For example, <mathemat>ics matches mathematical with one error (replacing the last s with an a),
but mathe<matics> does not match mathematical no matter how many errors are allowed. (This option
is buggy at the moment.)
Regular expressions
Since the index is word based, a regular expression must match words that appear in the index for
glimpse to find it. Glimpse first strips the regular expression from all non-alphabetic
characters, and searches the index for all remaining words. It then applies the regular
expression matching algorithm to the files found in the index. For example, glimpse 'abc.*xyz'
will search the index for all files that contain both 'abc' and 'xyz', and then search directly
for 'abc.*xyz' in those files. (If you use glimpse -w 'abc.*xyz', then 'abcxyz' will not be
found, because glimpse will think that abc and xyz need to be matches to whole words.) The syntax
of regular expressions in glimpse is in general the same as that for agrep. The union operation
`|', Kleene closure `*', and parentheses () are all supported. Currently '+' is not supported.
Regular expressions are currently limited to approximately 30 characters (generally excluding meta
characters). Some options (-d, -w, -t, -x, -D, -I, -S) do not currently work with regular
expressions. The maximal number of errors for regular expressions that use '*' or '|' is 4. (See
LIMITATIONS.)
structured queries
Glimpse supports some form of structured queries using Harvest's SOIF format. See STRUCTURED
QUERIES below for details.
EXAMPLES
(Run "glimpse '^glimpse' this-file" to get a list of all examples, some of which were given earlier.)
glimpse -F 'haystack.h$' needle
finds all needles in all haystack.h's files.
glimpse -2 -F html Anestesiology
outputs all occurrences of Anestesiology with two errors in files with html somewhere in their
full name.
glimpse -l -F '\.c$' variablename
lists the names of all .c files that contain variablename (the -l option lists file names rather
than output the matched lines).
glimpse -F 'mail;1993' 'windsurfing;Arizona'
finds all lines containing windsurfing and Arizona in all files having `mail' and '1993' somewhere
in their full name.
glimpse -F mail 't.j@#uk'
finds all mail addresses (search only files with mail somewhere in their name) from the uk, where
the login name ends with t.j, where the . stands for any one character. (This is very useful to
find a login name of someone whose middle name you don't know.)
glimpse -F mbox -h -G . > MBOX
concatenates all files whose name matches `mbox' into one big one.
SEARCHING IN COMPRESSED FILES
Glimpse includes an optional new compression program, called cast, which allows glimpse (and agrep) to
search the compressed files without having to decompress them. The search is actually significantly
faster when the files are compressed. However, we have not tested cast as thoroughly as we would have
liked, and a mishap in a compression algorithm can cause loss of data, so we recommend at this point to
use cast very carefully. We do not support or maintain cast. (Unless you specifically use cast, the
default is to ignore it.)
GLIMPSEINDEX FILES
All files used by glimpse are located at the directory(ies) where the index(es) is (are) stored and have
.glimpse_ as a prefix. The first two files (.glimpse_exclude and .glimpse_include) are optionally
supplied by the user. The other files are built and read by glimpse.
.glimpse_exclude
contains a list of files that glimpseindex is explicitly told to ignore. In general, the syntax
of .glimpse_exclude/include is the same as that of agrep (or any other grep). The lines in the
.glimpse_exclude file are matched to the file names, and if they match, the files are excluded.
Notice that agrep matches to parts of the string! e.g., agrep /ftp/pub will match /home/ftp/pub
and /ftp/pub/whatever. So, if you want to exclude /ftp/pub/core, you just list it, as is, in the
.glimpse_exclude file. If you put "/home/ftp/pub/cdrom" in .glimpse_exclude, every file name that
matches that string will be excluded, meaning all files below it. You can use ^ to indicate the
beginning of a file name, and $ to indicate the end of one, and you can use * and ? in the usual
way. For example /ftp/*html will exclude /ftp/pub/foo.html, but will also exclude
/home/ftp/pub/html/whatever; if you want to exclude files that start with /ftp and end with html
use ^/ftp*html$ Notice that putting a * at the beginning or at the end is redundant (in fact, in
this case glimpseindex will remove the * when it does the indexing). No other meta characters are
allowed in .glimpse_exclude (e.g., don't use .* or # or |). Lines with * or ? must have no more
than 30 characters. Notice that, although the index itself will not be indexed, the list of file
names (.glimpse_filenames) will be indexed unless it is explicitly listed in .glimpse_exclude.
.glimpse_filters
See the description above for the -z option.
.glimpse_include
contains a list of files that glimpseindex is explicitly told to include in the index even though
they may look like non-text files. Symbolic links are followed by glimpseindex only if they are
specifically included here. If a file is in both .glimpse_exclude and .glimpse_include it will be
excluded.
.glimpse_filenames
contains the list of all indexed file names, one per line. This is an ASCII file that can also be
used with agrep to search for a file name leading to a fast find command. For example,
glimpse 'count#\.c$' ~/.glimpse_filenames
will output the names of all (indexed) .c files that have 'count' in their name (including
anywhere on the path from the index). Setting the following alias in the .login file may be
useful:
alias findfile 'glimpse -h :1 ~/.glimpse_filenames'
.glimpse_index
contains the index. The index consists of lines, each starting with a word followed by a list of
block numbers (unless the -o or -b options are used, in which case each word is followed by an
offset into the file .glimpse_partitions where all pointers are kept). The block/file numbers are
stored in binary form, so this is not an ASCII file.
.glimpse_messages
contains the output of the -w option (see above).
.glimpse_partitions
contains the partition of the indexed space into blocks and, when the index is built with the -o
or -b options, some part of the index. This file is used internally by glimpse and it is a non-
ASCII file.
.glimpse_statistics
contains some statistics about the makeup of the index. Useful for some advanced applications and
customization of glimpse.
.glimpse_turbo
An added data structure (used under glimpseindex -o or -b only) that helps to speed up queries
significantly for large indexes. Its size is 0.25MB. Glimpse will work without it if needed.
STRUCTURED QUERIES
Glimpse can search for Boolean combinations of "attribute=value" terms by using the Harvest SOIF parser
library (in glimpse/libtemplate). To search this way, the index must be made by using the -s option of
glimpseindex (this can be used in conjunction with other glimpseindex options). For glimpse and
glimpseindex to recognize "structured" files, they must be in SOIF format. In this format, each value is
prefixed by an attribute-name with the size of the value (in bytes) present in "{}" after the name of the
attribute. For example, The following lines are part of an SOIF file:
type{17}: Directory-Listing
md5{32}: 3858c73d68616df0ed58a44d306b12ba
Any string can serve as an attribute name. Glimpse "pattern;type=Directory-Listing" will search for
"pattern" only in files whose type is "Directory-Listing". The file itself is considered to be one
"object" and its name/url appears as the first attribute with an "@" prefix; e.g., @FILE { http://xxx...
} The scope of Boolean operations changes from records (lines) to whole files when structured queries are
used in glimpse (since individual query terms can look at different attributes and they may not be
"covered" by the record/line). Note that glimpse can only search for patterns in the value parts of the
SOIF file: there are some attributes (like the TTL, MD5, etc.) that are interpreted by Harvest's internal
routines. See RFC 2655 for more detailed information of the SOIF format.
REFERENCES
1. U. Manber and S. Wu, "GLIMPSE: A Tool to Search Through Entire File Systems," Usenix Winter 1994
Technical Conference (best paper award), San Francisco (January 1994), pp. 23-32. Also, Technical
Report #TR 93-34, Dept. of Computer Science, University of Arizona, October 1993 (a postscript
file is available by anonymous ftp at ftp://webglimpse.net/pub/glimpse/TR93-34.ps).
2. S. Wu and U. Manber, "Fast Text Searching Allowing Errors," Communications of the ACM 35 (October
1992), pp. 83-91.
SEE ALSO
agrep(1), ed(1), ex(1), glimpseindex(1), glimpseserver(1), grep(1), sh(1), csh(1).
LIMITATIONS
The index of glimpse is word based. A pattern that contains more than one word cannot be found in the
index. The way glimpse overcomes this weakness is by splitting any multi-word pattern into its set of
words and looking for all of them in the index. For example, glimpse 'linear programming' will first
consult the index to find all files containing both linear and programming, and then apply agrep to find
the combined pattern. This is usually an effective solution, but it can be slow for cases where both
words are very common, but their combination is not.
As was mentioned in the section on PATTERNS above, some characters serve as meta characters for glimpse
and need to be preceded by '\' to search for them. The most common examples are the characters '.'
(which stands for a wild card), and '*' (the Kleene closure). So, "glimpse ab.de" will match abcde, but
"glimpse ab\.de" will not, and "glimpse ab*de" will not match ab*de, but "glimpse ab\*de" will. The meta
character - is translated automatically to a hyphen unless it appears between [] (in which case it
denotes a range of characters).
The index of glimpse stores all patterns in lower case. When glimpse searches the index it first
converts all patterns to lower case, finds the appropriate files, and then searches the actual files
using the original patterns. So, for example, glimpse ABCXYZ will first find all files containing abcxyz
in any combination of lower and upper cases, and then searches these files directly, so only the right
cases will be found. One problem with this approach is discovering misspellings that are caused by wrong
cases. For example, glimpse -B abcXYZ will first search the index for the best match to abcxyz (because
the pattern is converted to lower case); it will find that there are matches with no errors, and will go
to those files to search them directly, this time with the original upper cases. If the closest match
is, say AbcXYZ, glimpse may miss it, because it doesn't expect an error. Another problem is speed. If
you search for "ATT", it will look at the index for "att". Unless you use -w to match the whole word,
glimpse may have to search all files containing, for example, "Seattle" which has "att" in it.
There is no size limit for simple patterns and simple patterns within Boolean expressions. More
complicated patterns, such as regular expressions, are currently limited to approximately 30 characters.
Lines are limited to 1024 characters. Records are limited to 48K, and may be truncated if they are
larger than that. The limit of record length can be changed by modifying the parameter Max_record in
agrep.h.
Glimpseindex does not index words of size > 64.
BUGS
In some rare cases, regular expressions using * or # may not match correctly.
A query that contains no alphanumeric characters is not recommended (unless glimpse is used as agrep and
the file names are provided). This is an understatement.
The notion of "match to the whole word" (the -w option) can be tricky sometimes. For example, glimpse -w
'word$' will not match 'word' appearing at the end of a line, because the extra '$' makes the pattern
more than just one simple word. The same thing can happen with ^ and with _. To be on the safe side,
use the -w option only when the patterns are actual words.
Please send bug reports or comments to gvelez@webglimpse.net.
DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
AUTHORS
Udi Manber and Burra Gopal, Department of Computer Science, University of Arizona, and Sun Wu, the
National Chung-Cheng University, Taiwan. Now maintained by Golda Velez at Internet WorkShop (Email:
gvelez@webglimpse.net)
November 10, 1997 GLIMPSE(1)