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Command-line Option



The resource MIMEFILTERS is used to hook in user specifed filters into MHonArc. The MIMEFILTERS resource can only be set via the MIMEFILTERS element. The syntax for each line of the the MIMEFILTERS element is as follows:


The definition of each semi-colon-separated value is as follows:


The MIME content-type the filter processes. An explicit content-type (base/subtype) or a base content-type (base/*) can be specified.


The actual routine name of the filter. The name should be fully qualified by the package it is defined in (e.g. "mypackage::filter").


The name of the file that defines routine-name. If the file is not a full pathname, MHonArc finds the file by looking in the standard include paths of Perl, and the paths specified by the PERLINC resource.

Whitespace is stripped out for each filter specification.

Default Filters

MHonArc provides an existing set of filters which should be sufficient for most of your needs. For information about the filters, see the Available Filters section below.

Writing Filters

If you want to write your own filter for use in MHonArc, you need to know the Perl programming language. The following information assumes you know Perl.


As of v2.5 of MHonArc, the API for filters is different from v2.4.x, and earlier. The following describes the v2.5 API for filters.

Function Interface of Filter

MHonArc interfaces with MIME filters by calling a routine with a specific set of arguments. The prototype of the interface routine is as follows:

sub filter {
    my($fields_hash_ref, $body_data_ref, $is_decoded, $filter_args) = @_;

    # Filter code here

    # The last statement should be the return value, unless an
    # explicit return is done. See the following for the format of the
    # return value.
Parameter Descriptions

A reference to hash of message/part header fields. Keys are field names in lowercase and values are array references containing the field values. For example, to obtain the content-type, if defined, you would do:


Values for a fields are stored in arrays since duplication of fields are possible. For example, the Received: header field is typically repeated multiple times. For fields that only occur once, the array for the field will only contain one item.

See Special Variables and Header Fields for more information about this parameter.


Reference to body data. The filter can safely modify referenced data.


Boolean flag if body data has been decoded. This is normally true unless some non-standard content-transfer-encoding is used. See MIMEDECODERS on how to register decoders for various content-transfer-encodings.


This is an optional argument string that may be used to modify the behavior of the filter. The format of this string is determined by the filter itself. The value of the string is set by the MIMEARGS resource.

Return Value

The return value is treated as a list. The first item of the list is a string representing the HTML markup to insert in the HTMLized message. An empty string, or undef may be returned to tell MHonArc that the routine was unable to filter data.

Any other list items are treated as names of any files that were generated by the filter. MHonArc needs to keep track if any extra files that a filter may generate in order for MHonArc to delete those files if the message gets removed from the archive.


If you want MHonArc to treat the data as filtered, but not have anything displayed on the page, just return a string with a single space character.


If the filter creates a subdirectory with files, the filter only needs to return the subdirectory in the return list. If the message gets removed, MHonArc will delete the entire directory.

Special Variables and Header Fields

The following global variables are made available to filters:


Index key of message. Various MHonArc data structures and utility routines require the index key of the message.


Message ID of message.


Message number. The format of the number will at least be five digits wide, with leading zero padding. For example, if the number for a message is 15, $mhonarc::$MHAmsgnum will be equal to 00015.


Pathname to archive directory. This variable is useful for filters that create derived files.

The $fields_hash_ref parameter will have special MHonArc-specific keys defined. Unlike regular header field values, the values are not arrays (unless noted). The following special keys are defined:

my $charset = $fields_hash_ref->{'x-mha-charset'}

Only defined for text entities, the value represents the character set encoding of the text entity.

If your filter will take character encoding into account, you should use this value vs what is specified in regular entity header fields because TEXTENCODE may be affect, so the effective character encoding of the data may be different from the original encoding specified in the message.

my $content_type = $fields_hash_ref->{'x-mha-content-type'}

The media type of the entity extracted from content-type entity header.

my $part_no      = $fields_hash_ref->{'x-mha-part-number'}
my $full_part_no = readmail::gen_full_part_number($fields_hash_ref);

The child number of the entity within a multipart entity. Numbering starts with 1, and if data is not part of a multipart entity, this key may not be defined.

my $parent_header = $fields_hash_ref->{'x-mha-parent-header'}

The header field hash for the parent entity, if applicable.

Accessing Other Parts

For some media-types, a filter may need to access other entity parts to properly process a given part. For example, m2h_text_html::filter must access other entity parts when processing MHTML messages.

When MHonArc parses a multipart message, it fills the %readmail::Cid hash for each entity that defines either a Content-Id or Content-Location. The %readmail::Cid hash is mainly for use by media types, like multipart/related where message parts may reference other message parts.

The keys of the %readmail::Cid hash will be the Content-Ids and Content-Locations and each value will be a reference to an entity hash structure. Code example:

my $entity = $readmail::Cid{$content_id};

The hash structure defines the following fields:

my $entity_body_ref = $readmail::Cid{$content_id}->{'body'}

Scalar reference to the body of the entity.

my $entity_header_ref = $readmail::Cid{$content_id}->{'fields'}

Entity header fields hash reference. The format is the same as described for $fields_hash_ref.

my $is_filtered = $readmail::Cid{$content_id}->{'filtered'}

Boolean if part has already been filtered. This field should be set to a true value by filters that explicitly filters other entity parts. This tells MHonArc to not invoke a filter for the entity.

my $entity_uri = $readmail::Cid{$content_id}->{'uri'}

The URI to the filtered version of the entity. This field should be set by filters that explicitly filters other entity parts.

For a detailed example on how %readmail::Cid can be used, see the MHonArc library mhtxthtml.pl.

Utility Routines

See Utilities Routines in the appendix for various helper routines that can be used by your filter.

Filter Writing Tips

The following recommendations/tips are given to help you write filters:

Using C

If a MIME filter requires the utilization of a C program, or other non-Perl executable, a Perl wrapper must be written for the program in-order to interface with MHonArc. The wrapper must follow the conventions described in Writing Filters.

Available Filters

The following is the list of filters available in the standard MHonArc distribution:


The filters use a MIMEARGS argument style similiar to HTML attribute values. For example:

m2h_text_plain::filter; attachcheck fancyquote maxwidth=80

If writing your own filters, you are encouraged to use the same style for consistency.


The filter extracts the data into a separate file and puts a hyperlink to the file into the HTMLized message. The following is an example how the link is formatted:

Attachment: blueball.gif
Description: Blue ball GIF icon

The description text is retrieved from the Content-Disposition message header field, if defined. If not defined, a generic description will be provided based on the specified content-type of the data.

If the useicon filter argument has been specified for the filter, the following format will be used:

Attachment: blueball.gif
Description: Blue ball GIF icon

The actual icon used is based upon the ICONS resource.

By default, the filter ignores any filename specification given in the message when writing the data to disk. A unique filename with an extension based upon sub-type is generated.

m2h_external::filter can take the following MIMEARGS arguments:


A comma separated list of message specified filename extensions to exclude. I.e. If the filename extension matches an extension in excludeexts, the content will not be written. The return markup will contain the name of the attachment, but no link to the data. This option is best used with application/octet-stream to exclude unwanted data that is not tagged with the proper content-type.


Use ext as the filename extension. The filter already has a large list of extensions for various content-types. Use this argument if you process a content-type not recognized by the filter.


Force images to never be displayed inline, overriding any Content-Disposition setting.


Force images to be displayed inline, overriding any Content-Disposition setting.


Draw a border around the attachment link.


Use "url" as the url for the icon to use if the useicon option is set. This option will override any setting defined by the ICONS resource. The double quotes are required.


Inline image data by default if content-disposition not defined.


A comma separated list of message specified filename extensions to treat as possible inline data. Applicable when content-type is not image/* and usename or usenameext is in effect.


Use "description" as type description of the data. The double quotes are required. The filter already has a large list of descriptions for various content-types. Use this argument if you process a content-type not recognized by the filter.


Place derived file in a subdirectory of the archive. The subdirectory will be called "msgMSGNUM". This option may be useful if usename is specified to minimize security and name conflict problems.


Set the TARGET attribute of anchor link to file Default value is undefined (ie. no TARGET attribute will be written).


Include a content-type icon with the hyperlink to the derived file. The icon used is the value of the iconurl option or the icon defined by the ICONS resource.


Use (file)name attribute for determining name of derived file.


Use this option with caution since it can lead to filename conflicts and security problems.


Use (file)name attribute for determining the extension of derived file.


Use this option with caution since it can lead to security problems.

All arguments should be separated by at least one space.

The following table shows the default list of content-types with the filename extension used and a short description that m2h_external::filter recognizes:

application/astound asd Astound presentation
application/envoy evy Envoy file
application/fastman lcc fastman file
application/fractals fif Fractal Image Format
application/iges iges IGES file
application/mac-binhex40 hqx Mac BinHex archive
application/mathematica ma Mathematica Notebook document
application/mbedlet mbd mbedlet file
application/ms-excel xls MS-Excel spreadsheet
application/ms-powerpoint ppt MS-Powerpoint presentation
application/ms-project mpp MS-Project file
application/msword doc MS-Word document
application/octet-stream bin Binary data
application/oda oda ODA file
application/pdf pdf Adobe PDF document
application/pgp pgp PGP message
application/pgp-signature pgp PGP signature
application/pkcs7-mime p7m S/MIME encrypted message
application/pkcs7-signature p7s S/MIME cryptographic signature
application/postscript ps PostScript document
application/rtf rtf RTF file
application/sgml sgml SGML document
application/studiom smp Studio M file
application/timbuktu tbt timbuktu file
application/vis5d v5d Vis5D dataset
application/vnd.framemaker fm FrameMaker document
application/vnd.hp-hpgl hpg HPGL file
application/vnd.lotus-1-2-3 123 Lotus 1-2-3
application/vnd.lotus-approach apr Lotus Approach
application/vnd.lotus-freelance prz Lotus Freelance
application/vnd.lotus-organizer org Lotus Organizer
application/vnd.lotus-screencam scm Lotus Screencam
application/vnd.lotus-wordpro lwp Lotus WordPro
application/vnd.mif mif Frame MIF document
application/vnd.ms-excel xls MS-Excel spreadsheet
application/vnd.ms-powerpoint ppt MS-Powerpoint presentation
application/vnd.ms-project mpp MS-Project file
application/vnd.stardivision.calc sdc StarCalc spreadsheet
application/vnd.stardivision.chart sds StarChart document
application/vnd.stardivision.draw sda StarDraw document
application/vnd.stardivision.impress sdd StarImpress presentation
application/vnd.stardivision.impress-packed sdp StarImpress packed file
application/vnd.stardivision.mail smd StarMail mail file
application/vnd.stardivision.math smf StarMath document
application/vnd.stardivision.writer sdw StarWriter document
application/vnd.stardivision.writer-global sgl StarWriter global document
application/vnd.sun.xml.calc sxc OpenOffice Calc spreadsheet
application/vnd.sun.xml.calc.template stc OpenOffice Calc template
application/vnd.sun.xml.draw sxd OpenOffice Draw document
application/vnd.sun.xml.draw.template std OpenOffice Draw Template
application/vnd.sun.xml.impress sxi OpenOffice Impress presentation
application/vnd.sun.xml.impress.template sti OpenOffice Impress template
application/vnd.sun.xml.math sxm OpenOffice Math documents
application/vnd.sun.xml.writer sxw OpenOffice Writer document
application/vnd.sun.xml.writer.global sxg OpenOffice Writer global document
application/vnd.sun.xml.writer.template stw OpenOffice Write template
application/winhlp hlp WinHelp document
application/wordperfect5.1 wp WordPerfect 5.1 document
application/x-asap asp asap file
application/x-bcpio bcpio BCPIO file
application/x-bzip2 bz2 BZip2 compressed data
application/x-compress Z Unix compressed data
application/x-cpio cpio CPIO file
application/x-csh csh C-Shell script
application/x-dot dot dot file
application/x-dvi dvi TeX dvi file
application/x-earthtime etc Earthtime file
application/x-envoy evy Envoy file
application/x-excel xls MS-Excel spreadsheet
application/x-gtar gtar GNU Unix tar archive
application/x-gzip gz GNU Zip compressed data
application/x-hdf hdf HDF file
application/x-javascript js JavaScript source
application/x-ksh ksh Korn Shell script
application/x-latex latex LaTeX document
application/x-maker fm FrameMaker document
application/x-mif mif Frame MIF document
application/x-mocha moc mocha file
application/x-msaccess mdb MS-Access database
application/x-mscardfile crd MS-CardFile
application/x-msclip clp MS-Clip file
application/x-msmediaview m14 MS-Media View file
application/x-msmetafile wmf MS-Metafile
application/x-msmoney mny MS-Money file
application/x-mspublisher pub MS-Publisher document
application/x-msschedule scd MS-Schedule file
application/x-msterminal trm MS-Terminal
application/x-mswrite wri MS-Write document
application/x-net-install ins Net Install file
application/x-netcdf cdf Cdf file
application/x-ns-proxy-autoconfig proxy Netscape Proxy Auto Config
application/x-patch patch Source code patch
application/x-perl pl Perl program
application/x-pointplus css pointplus file
application/x-salsa slc salsa file
application/x-script script A script file
application/x-sh sh Bourne shell script
application/x-shar shar Unix shell archive
application/x-sprite spr sprite file
application/x-stuffit sit Macintosh archive
application/x-sv4cpio sv4cpio SV4Cpio file
application/x-sv4crc sv4crc SV4Crc file
application/x-tar tar Unix tar archive
application/x-tcl tcl Tcl script
application/x-tex tex TeX document
application/x-texinfo texinfo TeXInfo document
application/x-timbuktu tbp timbuktu file
application/x-tkined tki tkined file
application/x-troff roff Troff document
application/x-troff-man man Unix manual page
application/x-troff-me me Troff ME-macros document
application/x-troff-ms ms Troff MS-macros document
application/x-ustar ustar UStar file
application/x-wais-source src WAIS Source
application/x-zip-compressed zip Zip compressed data
application/xml xml XML document
application/zip zip Zip archive
audio/basic snd Basic audio
audio/echospeech es Echospeech audio
audio/microsoft-wav wav Wave audio
audio/midi midi MIDI audio
audio/wav wav Wave audio
audio/x-aiff aif AIF audio
audio/x-epac pae epac audio
audio/x-midi midi MIDI audio
audio/x-mpeg mp2 MPEG audio
audio/x-pac pac pac audio
audio/x-pn-realaudio ra PN Realaudio
audio/x-wav wav Wave audio
chemical/chem3d c3d Chem3d chemical test
chemical/chemdraw chm Chemdraw chemical test
chemical/cif cif CIF chemical test
chemical/cml cml CML chemical test
chemical/cmsl cml Chemical Structure Markup
chemical/cxf cxf Chemical Exhange Format file
chemical/daylight-smiles smi SMILES format file
chemical/embl-dl-nucleotide emb EMBL nucleotide format file
chemical/gaussian gau Gaussian data
chemical/gaussian-input gau Gaussian input data
chemical/gaussian-log gal Gaussian log
chemical/gcg8-sequence gcg GCG format file
chemical/genbank gen GENbank data
chemical/jcamp-dx jdx Jcamp chemical spectra test
chemical/kinemage kin Kinemage
chemical/macromodel-input mmd Macromodel chemical test
chemical/mdl-molfile mol MOL mdl chemical test
chemical/mdl-rdf rdf RDF chemical test
chemical/mdl-rxn rxn RXN chemical test
chemical/mdl-sdf sdf SDF chemical test
chemical/mdl-tgf tgf TGF chemical test
chemical/mif mif MIF chemical test
chemical/mmd mmd Macromodel data
chemical/mopac-input mop MOPAC data
chemical/ncbi-asn1 asn NCBI data
chemical/ncbi-asn1-binary val NCBI data
chemical/pdb pdb Protein Databank data
chemical/rosdal ros Rosdal data
chemical/xyz xyz Xmol XYZ data
image/bmp bmp Windows bitmap
image/cgm cgm Computer Graphics Metafile
image/fif fif Fractal Image Format image
image/g3fax g3f Group III FAX image
image/gif gif GIF image
image/ief ief IEF image
image/ifs ifs IFS image
image/jpeg jpg JPEG image
image/pbm pbm Portable bitmap
image/pgm pgm Portable graymap
image/png png PNG image
image/tiff tif TIFF image
image/vnd dwg VND image
image/wavelet wi Wavelet image
image/x-cmu-raster ras CMU raster
image/x-pbm pbm Portable bitmap
image/x-pcx pcx PCX image
image/x-pgm pgm Portable graymap
image/x-pict pict Mac PICT image
image/x-pnm pnm Portable anymap
image/x-portable-anymap pnm Portable anymap
image/x-portable-bitmap pbm Portable bitmap
image/x-portable-graymap pgm Portable graymap
image/x-portable-pixmap ppm Portable pixmap
image/x-ppm ppm Portable pixmap
image/x-rgb rgb RGB image
image/x-xbitmap xbm X bitmap
image/x-xbm xbm X bitmap
image/x-xpixmap xpm X pixmap
image/x-xpm xpm X pixmap
image/xwd xwd X window dump
image/xwindowdump xwd X window dump
message/news 822 News post
message/rfc822 822 Mail message
model/iges iges IGES model
model/mesh mesh Mesh model
model/vrml wrl VRML model
text/enriched rtx Text-enriched document
text/html html HTML document
text/plain txt Text document
text/richtext rtx Richtext document
text/setext stx Setext document
text/sgml sgml SGML document
text/tab-separated-values tsv Tab separated values
text/x-speech talk Speech document
text/x-vcard vcf Vcard
text/xml xml XML document
video/isivideo fvi isi video
video/mpeg mpg MPEG movie
video/msvideo avi MS Video
video/quicktime mov QuickTime movie
video/vivo viv vivo video
video/wavelet wv Wavelet video
video/x-sgi-movie movie SGI movie


This filter is designed to process message/external-body data. The filter attempts to translate the external-body paramaters into a linked URL with some descriptive information, if provided. The following access-types are supported: ANON-FTP, FTP, TFTP, HTTP, LOCAL-FILE, and URL. Note, LOCAL-FILE is only supported if the local-file option is specified.

m2h_msg_extbody::filter can take the following MIMEARGS arguments:


Support LOCAL-FILE access-type. This option is best used for internal local mail archives where it is known that readers will have direct access to the file.


This filter is designed to process text/enriched, or text/richtext, data. The following table summarizes the translation of text/enriched commands to HTML tags:

Text/Enriched CommandHTML Translation
<Bold> <b>
<Italic> <i>
<Underline> <u>
<Fixed> <tt>
<Smaller> <small>
<Bigger> <big>
<FontFamily><Param>family</Param> <font face="family">
<Color><Param>color</Param> <font color="color">
<Center> <p align="center">
<FlushLeft> <p align="left">
<FlushRight> <p align="right">
<FlushBoth> <p align="justify">
<ParaIndent> <blockquote>
<Excerpt> <blockquote>
<Lang><Param>lang</Param> <div lang="lang">

Character data will be translated as specified by the CHARSETCONVERTERS resources.



For security reasons, it is highly recommended to disable support of HTML messages in your mail archives. There is no guarantee this filter is robust enough to eliminate all possible exploits that can occur with HTML data. See the following FAQ questions for more information:

This filter is designed to process text/html, or text/x-html, data. The following modifications are done to HTML documents when processed by MHonArc:

m2h_text_html::filter can take the following MIMEARGS arguments:


Preserve any comment declarations. By default, comment declarations are munged to protect against potential exploits, but this option will disable that behavior.


Using this option can open up security vulnerabilies, including the accessing of server resources. If you have server-side includes enabled for your site, you SHOULD NOT use this option.


Preserve URL-based attributes that are not cid: URLs. By default, any URL-based attribute -- href, src, background, classid, data, longdesc -- will be stripped if it is not a cid URL. This prevents malicious URLs from verifying mail addresses, secretly setting cookies, or gathering statistical data with the use of elements that cause browsers to automatically fetch data without user interaction: IMG, BODY, IFRAME, FRAME, OBJECT, SCRIPT, INPUT.


Href attributes for anchor, <A>, elements are preserved, even if allownoncidurls is not specified. This is so regular hyperlinks will function. Javascript URLs will still be munged (unless the allowscript option is specified).


Preserve any markup associated with scripting. This includes elements and attributes related to scripting.


Use of this option can open up your archives to cross-site scripting (XSS) attacks. It is highly recommended to NOT use this option, especially for publicly accessible archives.


Honor attachment disposition. By default, all text/html data is displayed inline on the message page. If attachcheck is specified and Content-Disposition specifies the data as an attachment, the data is saved to a file with a link to it from the message page.


If attachcheck is specified, the HTML data is saved "as-is". For example, no stripping of scripting-based markup is performed and no resolution of cid URLs are performed, allowing your archive to be used for cross-site scripting (XSS) exploits. This option SHOULD NOT BE USED for archives unless all mail from all senders can be trusted.


Disable processing of related parts processing: cid URLs will not be resolved.


Remove font tags and styles, including CSS styles.


Do not print extracted title at the beginning of converted output. By default, the title is printed before the document body. The notitle argument disables this behavior.


Place attachment files in a subdirectory of the archive. This option is used for MHTML messages that include inline images are other referenced data.


This filter is designed to process text/plain messages and messages with no MIME information. The filter is also used to process text messages of an unknown subtype.

The default behavior of the filter is to wrap the data in the HTML PRE element and escape special characters. It also converts text that looks like a URL into a hyperlink. Character data will be translated as specified by the CHARSETCONVERTERS resources.

This filter supports text data donoted with flowed sematics as defined by RFC 2646. Quoted text will be wrapped in HTML BLOCKQUOTE tags with inline CSS styles to highlight quoted text with a vertical bar in the left margin:

This is some quoted text. This is some quoted text. This is some quoted text. This is some quoted text. This is some quoted text.

CSS style customization can be done by using the quoteclass argument described below.

m2h_text_plain::filter can take the following MIMEARGS arguments:


Colon separated lists of charsets to leave as-is. Only HTML special characters will be converted into entities.


The asis option is deprecated. It is recommended to use the CHARSETCONVERTERS resource to control how character data is converted.


Honor attachment disposition. By default, all text/plain data is displayed inline on the message page. If attachcheck is specified and Content-Disposition specifies the data as an attachment, the data is saved to a file with a link to it from the message page.


Flowed sematics will be ignored for text denoted with flowed formatting.


The effects of fancyquote and quote will still occur if either option is specified.


Highlight quoted message text. Quoted text will be wrapped in HTML BLOCKQUOTE elements. By default, inline CSS style settings are generated to render a vertical bar in the left margin. The inline styles are suppressed if the quoteclass option is set.

This option generates similiar rendering of quoted text as is done for flowed text data, but without the flowed text wrapping sematics.


If message text is denoted as flowed text by message headers, the text will always be rendered with flowed sematics unless the disableflowed option is specified.


Check if message is actually an HTML message (to get around abhorrent MUAs). The message is treated as HTML if the first non-whitespace data looks like the start of an HTML document.

If the data looks like HTML, the HTML filter will be invoked on it.


A comma separated list of message specified filename extensions to treat as inline data. Applicable only when uudecode and usename are specified.


Preserve all spaces if the nonfixed option is specified. All spaces and tabs will be translated to the equivalent number of &nbsp; entity references.


A comma separated list of URL schemes denoting which URLs to convert into hyperlinks. By default, all URLs will be converted into hyperlinks. This option allows you to restrict the set of URLs converted.

Compare this argument with nolink.


Force the maximum width of lines to be # characters in length. Any lines longer than # characters will be wrapped.


A line that contains no whitespace and is longer than maxwidth, will not be wrapped.


A comma separated list of URL schemes denoting which URLs to not convert into hyperlinks. By default, all URLs will be converted into hyperlinks. This option allows you to specify URLs that should never be converted.

Compare this argument with link.


Do not wrap message text in the HTML PRE element. This will cause text to be rendered in the default font (which is normally proportionally spaced). Each line of the message will have a <br> appended in order to preserve the line representation of the message.


Do not hyperlink URLs. This option overrides link and nolink.


Italicize quoted message text. Any quoted lines in the message will be wrapped in the HTML I element. Compare this option with the fancyquote option.


CSS classname to use for quoted text. This option applies only for flowed text data or if fancyquote is specified. The classname will be the value of the CLASS attbribute for the BLOCKQUOTE elements, and this option suppresses the generation of inline styles.

This option is useful if a master stylesheet controls the appearance of archives. By using this option, the master stylesheet can be used to control the rendering of quoted text.


Place attachment files in a subdirectory of the archive. This option is only applicable if uudecode is specified.


Set the TARGET attribute of anchors generated from hyperlinking URLs.


When decoding uuencoded data, use the full filename specified in the message instead of the filename extension.


Use this option with caution since it can lead to filename conflicts and security problems. If you plan on using usename, consider using the subdir option with it.


Decode any embedded uuencoded data. Including uuencoded data within messages was a way to transmit binary data via email before MIME was developed. The inclusion of uuencoded data is deprecated within email, but is still common in the USENET (binary) newsgroups.

Uuencoded data is treated as application/octet-stream for data exclusion purposes: MIMEEXCS. If application/octet-stream data is listed in MIMEEXCS, uuencoded data will be excluded.


Specifying uudecode adds extra overhead in the processing of text messages, including messages without any uuencoded data.


This filter converts text/tab-separated-values to HTML. The tabular data will be converted into an HTML table.


This filter can be used to exclude message content from archives. You can register this filter to any content-type you do not want to store in your archives. For example, the following resource setting excludes all images:

image/*; m2h_null::filter; mhnull.pl

The markup returned by this filter displays the one line description of what was excluded. Examples:

<<attachment: HelloWorld.jpg>>
<<inline: image/jpg>>

If the disposition is available, it will be shown. If a filename was specified, it will be shown. If there was no filename, the content-type is shown.


The sematics of using the MIMEEXCS resource vs this filter are different. When using this filter, MHonArc considers the data successfully converted. But with MIMEEXCS, MHonArc does not consider the data converted. This is relevant when MHonArc determines which alternative part to use for an multipart/alternative entity.

Default Setting


It is important to have an explicit entry for application/octet-stream for handling unknown media-types.

application/octet-stream;  m2h_external::filter;	mhexternal.pl
application/*;		   m2h_external::filter;	mhexternal.pl
application/x-patch;	   m2h_text_plain::filter;	mhtxtplain.pl
audio/*;		   m2h_external::filter;	mhexternal.pl
chemical/*;		   m2h_external::filter;	mhexternal.pl
model/*;		   m2h_external::filter;	mhexternal.pl
image/*;		   m2h_external::filter;	mhexternal.pl
message/delivery-status;   m2h_text_plain::filter;	mhtxtplain.pl
message/external-body;     m2h_msg_extbody::filter;	mhmsgextbody.pl
message/partial;	   m2h_text_plain::filter;	mhtxtplain.pl
text/*;			   m2h_text_plain::filter;	mhtxtplain.pl
text/enriched;		   m2h_text_enriched::filter;	mhtxtenrich.pl
text/html;		   m2h_text_html::filter;	mhtxthtml.pl
text/plain;		   m2h_text_plain::filter;	mhtxtplain.pl
text/richtext;		   m2h_text_enriched::filter;	mhtxtenrich.pl
text/tab-separated-values; m2h_text_tsv::filter;	mhtxttsv.pl
text/x-html;		   m2h_text_html::filter;	mhtxthtml.pl
video/*;		   m2h_external::filter;	mhexternal.pl
x-sun-attachment;	   m2h_text_plain::filter;	mhtxtplain.pl

Resource Variables



The following code is an example filter for converting text/tab-separated-values into an HTML table:

package m2h_text_tsv;

sub filter {
    my($fields, $data, $isdecode, $args) = @_;
    my($field, $line, $ret);

    $$data =~ s/^\s+//;
    $ret  = "<table border=1>\n";
    foreach $line (split(/\r?\n/, $$data)) {
	$ret .= "<tr>";
	foreach $field (split(/\t/, $line)) {
	    $ret .= '<td>' . mhonarc::htmlize($field) . '</td>';
	$ret .= "</tr>\n";
    $ret .= "</table>\n";




See Also


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$Date: 2010/12/31 20:33:59 $
Copyright © 1997-2005 Earl Hood, mhonarc@mhonarc.org