/ 
Mail-SpamAssassin-4.0.3-rc1-TRIAL
/ Mail::SpamAssassin::Plugin::ExtractText

NAME

ExtractText - extracts text from documenmts.

SYNOPSIS

loadplugin Mail::SpamAssassin::Plugin::ExtractText

ifplugin Mail::SpamAssassin::Plugin::ExtractText

extracttext_external  pdftotext  /usr/bin/pdftotext -nopgbrk -layout -enc UTF-8 {} -
extracttext_use       pdftotext  .pdf application/pdf

# http://docx2txt.sourceforge.net
extracttext_external  docx2txt   /usr/bin/docx2txt {} -
extracttext_use       docx2txt   .docx application/docx

extracttext_external  antiword   /usr/bin/antiword -t -w 0 -m UTF-8.txt {}
extracttext_use       antiword   .doc application/(?:vnd\.?)?ms-?word.*

extracttext_external  unrtf      /usr/bin/unrtf --nopict {}
extracttext_use       unrtf      .doc .rtf application/rtf text/rtf

extracttext_external  odt2txt    /usr/bin/odt2txt --encoding=UTF-8 {}
extracttext_use       odt2txt    .odt .ott application/.*?opendocument.*text
extracttext_use       odt2txt    .sdw .stw application/(?:x-)?soffice application/(?:x-)?starwriter

extracttext_external  tesseract  {OMP_THREAD_LIMIT=1} /usr/bin/tesseract -c page_separator= {} -
extracttext_use       tesseract  .jpg .png .bmp .tif .tiff image/(?:jpeg|png|x-ms-bmp|tiff)

# QR-code decoder
extracttext_external  zbar       /usr/bin/zbarimg -q -D {}
extracttext_use       zbar       .jpg .png .pdf image/(?:jpeg|png) application/pdf

add_header   all          ExtractText-Flags _EXTRACTTEXTFLAGS_
header       PDF_NO_TEXT  X-ExtractText-Flags =~ /\bpdftotext_NoText\b/
describe     PDF_NO_TEXT  PDF without text
score        PDF_NO_TEXT  0.001

header       DOC_NO_TEXT  X-ExtractText-Flags =~ /\b(?:antiword|openxml|unrtf|odt2txt)_NoText\b/
describe     DOC_NO_TEXT  Document without text
score        DOC_NO_TEXT  0.001

header       EXTRACTTEXT  exists:X-ExtractText-Flags
describe     EXTRACTTEXT  Email processed by extracttext plugin
score        EXTRACTTEXT  0.001

endif

DESCRIPTION

This module uses external tools to extract text from message parts, and then sets the text as the rendered part. External tool must output plain text, not HTML or other non-textual result.

How to extract text is completely configurable, and based on MIME part type and file name.

CONFIGURATION

All configuration lines in user_prefs files will be ignored.

extracttext_maxparts (default: 10)

Configure the maximum mime parts number to analyze, a value of 0 means all mime parts will be analyzed

extracttext_timeout (default: 5 10)

Configure the timeout in seconds of external tool checks, per attachment.

Second argument specifies maximum total time for all checks.

Tools

extracttext_use

Specifies what tool to use for what message parts.

The general syntax is

extracttext_use name specifiers

name

the internal name of a tool.

specifiers

File extension and regular expressions for file names and MIME types. The regular expressions are anchored to beginning and end.

Examples

extracttext_use  antiword  .doc application/(?:vnd\.?)?ms-?word.*
extracttext_use  openxml   .docx .dotx .dotm application/(?:vnd\.?)openxml.*?word.*
extracttext_use  openxml   .doc .dot application/(?:vnd\.?)?ms-?word.*
extracttext_use  unrtf     .doc .rtf application/rtf text/rtf
extracttext_external

Defines an external tool. The tool must read a document on standard input or from a file and write text to standard output.

The special keyword "{}" will be substituted at runtime with the temporary filename to be scanned by the external tool.

Environment variables can be defined with "{KEY=VALUE}", these strings will be removed from commandline.

It is required that commandline used outputs result directly to STDOUT.

The general syntax is

extracttext_external name command parameters

name

The internal name of this tool.

command

The full path to the external command to run.

parameters

Parameters for the external command. The temporary file name containing the document will be automatically added as last parameter.

Examples

extracttext_external  antiword  /usr/bin/antiword -t -w 0 -m UTF-8.txt {} -
extracttext_external  unrtf     /usr/bin/unrtf --nopict {}
extracttext_external  odt2txt   /usr/bin/odt2txt --encoding=UTF-8 {}

Metadata

The plugin adds some pseudo headers to the message. These headers are seen by the bayes system, and can be used in normal SpamAssassin rules.

The headers are also available as template tags as noted below.

Example

The fictional example headers below are based on a message containing this:

1 A perfectly normal PDF.
2 An OpenXML document with a word document inside. Neither Office document contains text.

Headers

X-ExtractText-Chars

Tag: _EXTRACTTEXTCHARS_

Contains a count of characters that were extracted.

X-ExtractText-Chars: 10970

X-ExtractText-Words

Tag: _EXTRACTTEXTWORDS_

Contains a count of "words" that were extracted.

X-ExtractText-Chars: 1599

X-ExtractText-Tools

Tag: _EXTRACTTEXTTOOLS_

Contains chains of tools used for extraction.

X-ExtractText-Tools: pdftotext openxml_antiword

X-ExtractText-Types

Tag: _EXTRACTTEXTTYPES_

Contains chains of MIME types for parts found during extraction.

X-ExtractText-Types: application/pdf; application/vnd.openxmlformats-officedocument.wordprocessingml.document, application/ms-word

X-ExtractText-Extensions

Tag: _EXTRACTTEXTEXTENSIONS_

Contains chains of canonicalized file extensions for parts found during extraction.

X-ExtractText-Extensions: pdf docx

X-ExtractText-Flags

Tag: _EXTRACTTEXTFLAGS_

Contains notes from the plugin.

X-ExtractText-Flags: openxml_NoText

X-ExtractText-Uris

Tag: _EXTRACTTEXTURIS_

Contains uris extracted from the plugin.

X-ExtractText-Uris: https://spamassassin.apache.org

Rules

Example:

header    PDF_NO_TEXT  X-ExtractText-Flags =~ /\bpdftotext_Notext\b/
describe  PDF_NO_TEXT  PDF without text

ADMINISTRATOR SETTINGS

extracttext_cache_type (default: none)

The cache type that is being utilized. Currently only supported value is dbi that implies extracttext_cache_dsn is a DBI connect string. DBI module is required.

Example: extracttext_cache_type dbi

extracttext_cache_dsn (default: none)

The DBI dsn of the database to use.

For SQLite, the database will be created automatically if it does not already exist, the supplied path and file must be read/writable by the user running spamassassin or spamd.

For MySQL/MariaDB or PostgreSQL, see sql-directory for database table creation clauses.

You will need to have the proper DBI module for your database. For example DBD::SQLite, DBD::mysql, DBD::MariaDB or DBD::Pg.

Minimum required SQLite version is 3.24.0 (available from DBD::SQLite 1.59_01).

Examples:

extracttext_cache_dsn dbi:SQLite:dbname=/var/lib/spamassassin/ExtractText.db
extracttext_cache_username (default: none)

The username that should be used to connect to the database. Not used for SQLite.

extracttext_cache_password (default: none)

The password that should be used to connect to the database. Not used for SQLite.

extracttext_cache_ttl (default: 86400)

The length of time a cache entry will be valid for in seconds. Default is 86400 (1 day).

See extracttext_cache_autoclean for database cleaning.

extracttext_cache_autoclean (default: 1000)

Automatically purge old entries from database. Value describes a random run chance of 1/x. The default value of 1000 means that cleaning is run approximately once for every 1000 messages processed. Value of 1 would mean database is cleaned every time a message is processed.

Set 0 to disable automatic cleaning and to do it manually.