---
name: "archer"
section: "1"
platform: "linux"
package: "libbow"
version: "20020213-10"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/archer"
---

# archer(1)

AltaVista-style document retrieval front-end using libbow

## NAME

archer -  AltaVista-style document retrieval front-end using libbow

## SYNOPSIS

**archer** \[*OPTION*...\] \[*ARG*...\]

## DESCRIPTION

**Archer** is a standalone program that does document retrieval with AltaVista-type queries, using +, -, "", etc.  The commands in the **arrow** examples in the manpage also work for archer.

## OPTIONS

-

  For building data structures from text files:

- **-i**, **--index**=*DIRNAME*

  Tokenize training documents found under DIRNAME, and save them to disk

- **--index-lines**=*FILENAME* Like **--index**, except index each line of FILENAME

  as if it were a separate document.  Documents are named after sequential line numbers.

-

  For doing document retreival using the data structures built with **-i**:

- **-n**, **--num-hits-to-show**=*N*

  Show the N documents that are most similar to the query text (default N=1)

- **-q**, **--query**=*WORDS*

  tokenize input from stdin \[or FILE\], then print document most like it

- **--query-forking-server**=*PORTNUM*

  Run archer in socket server mode, forking a new process with every connection.  Allows multiple simultaneous connections.

**--query-server**=*PORTNUM* Run archer in socket server mode.

- **--score-is-raw-count**

  Instead of using a weighted sum of logs, the score of a document will be simply the number of terms in both the query and the document.

-

  Diagnostics

- **-p**, **--print-all**

  Print, in unsorted order, all the document indices, positions and words

- **-s**, **--print-word-stats**

  Print the number of times each word occurs.

-

  General options

- **--annotations**=*FILE*

  The sarray file containing annotations for the files in the index

- **-b**, **--no-backspaces**

  Don't use backspace when verbosifying progress (good for use in emacs)

- **-d**, **--data-dir**=*DIR*

  Set the directory in which to read/write word-vector data (default=~/.\<program\_name\>).

- **--random-seed**=*NUM*

  The non-negative integer to use for seeding the random number generator

- **--score-precision**=*NUM*

  The number of decimal digits to print when displaying document scores

- **-v**, **--verbosity**=*LEVEL*

  Set amount of info printed while running; (0=silent, 1=quiet, 2=show-progess,...5=max)

-

  Lexing options

- **--append-stoplist-file**=*FILE*

  Add words in FILE to the stoplist.

- **--exclude-filename**=*FILENAME*

  When scanning directories for text files, skip files with name matching FILENAME.

- **-g**, **--gram-size**=*N*

  Create tokens for all 1-grams,... N-grams.

- **-h**, **--skip-header**

  Avoid lexing news/mail headers by scanning forward until two newlines.

- **--istext-avoid-uuencode**

  Check for uuencoded blocks before saying that the file is text, and say no if there are many lines of the same length.

- **--lex-pipe-command**=*SHELLCMD*

  Pipe files through this shell command before lexing them.

- **--max-num-words-per-document**=*N*

  Only tokenize the first N words in each document.

- **--no-stemming**

  Do not modify lexed words with a stemming function. (usually the default, depending on lexer)

- **--no-stoplist**

  Do not toss lexed words that appear in the stoplist.

- **--replace-stoplist-file**=*FILE*

  Empty the default stoplist, and add space-delimited words from FILE.

- **--shortest-word**=*LENGTH* Toss lexed words that are shorter than LENGTH.

  Default is usually 2.

- **-S**, **--use-stemming**

  Modify lexed words with the \`Porter' stemming function.

- **--use-stoplist**

  Toss lexed words that appear in the stoplist. (usually the default SMART stoplist, depending on lexer)

- **--use-unknown-word**

  When used in conjunction with **-O** or **-D**, captures all words with occurrence counts below threshold as the \`\<unknown\>' token

- **--xxx-words-only**

  Only tokenize words with \`xxx' in them

-

  Mutually exclusive choice of lexers

- **--flex-mail**

  Use a mail-specific flex lexer

- **--flex-tagged**

  Use a tagged flex lexer

- **-H**, **--skip-html**

  Skip HTML tokens when lexing.

- **--lex-alphanum**

  Use a special lexer that includes digits in tokens, delimiting tokens only by non-alphanumeric characters.

- **--lex-infix-string**=*ARG* Use only the characters after ARG in each word for

  stoplisting and stemming.  If a word does not contain ARG, the entire word is used.

- **--lex-suffixing**

  Use a special lexer that adds suffixes depending on Email-style headers.

- **--lex-white**

  Use a special lexer that delimits tokens by whitespace only, and does not change the contents of the token at all---no downcasing, no stemming, no stoplist, nothing.  Ideal for use with an externally-written lexer interfaced to rainbow with **--lex-pipe-cmd**.

-

  Feature-selection options

- **-D**, **--prune-vocab-by-doc-count**=*N*

  Remove words that occur in N or fewer documents.

- **-O**, **--prune-vocab-by-occur-count**=*N*

  Remove words that occur less than N times.

- **-T**, **--prune-vocab-by-infogain**=*N*

  Remove all but the top N words by selecting words with highest information gain.

-

  Weight-vector setting/scoring method options

- **--binary-word-counts**

  Instead of using integer occurrence counts of words to set weights, use binary absence/presence.

- **--event-document-then-word-document-length**=*NUM*

  Set the normalized length of documents when **--event-model**=*document-then-word*

- **--event-model**=*EVENTNAME*

  Set what objects will be considered the \`events' of the probabilistic model.  EVENTNAME can be one of: word, document, document-then-word.

-

  Default is \`word'.

- **--infogain-event-model**=*EVENTNAME*

  Set what objects will be considered the \`events' when information gain is calculated.  EVENTNAME can be one of: word, document, document-then-word.

-

  Default is \`document'.

- **-m**, **--method**=*METHOD*

  Set the word weight-setting method; METHOD may be one of:

- **--print-word-scores**

  During scoring, print the contribution of each word to each class.

- **--smoothing-dirichlet-filename**=*FILE*

  The file containing the alphas for the dirichlet smoothing.

- **--smoothing-dirichlet-weight**=*NUM*

  The weighting factor by which to muliply the alphas for dirichlet smoothing.

- **--smoothing-goodturing-k**=*NUM*

  Smooth word probabilities for words that occur NUM or less times. The default is 7.

- **--smoothing-method**=*METHOD*

  Set the method for smoothing word probabilities to avoid zeros; METHOD may be one of: goodturing, laplace, mestimate, wittenbell

- **--uniform-class-priors** When setting weights, calculating infogain and

  scoring, use equal prior probabilities on classes.

- \-?, **--help**

  Give this help list

- **--usage**

  Give a short usage message

- **-V**, **--version**

  Print program version

Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

## REPORTING BUGS

Please report bugs related to this program to Andrew McCallum \<mccallum@cs.cmu.edu\>. If the bugs are related to the Debian package send bugs to submit@bugs.debian.org

## SEE ALSO

[**rainbow**(1)](/rainbow/1.md), [**arrow**(1)](/arrow/1.md), [**crossbow**(1)](/crossbow/1.md).

The full documentation for **arrow** will be provided as a Texinfo manual.  If the **info** and **arrow** programs are properly installed at your site, the command

-

  **info arrow**

should give you access to the complete manual.

You can also find documentation and updates for **libbow** at http://www.cs.cmu.edu/~mccallum/bow