# mhbuild(1mh) - man - phpMan [MHBUILD(1mh)](https://www.chedong.com/phpMan.php/man/MHBUILD/1mh/markdown) [MHBUILD(1mh)](https://www.chedong.com/phpMan.php/man/MHBUILD/1mh/markdown) ## NAME mhbuild - translate MIME composition drafts for nmh messages ## SYNOPSIS **mhbuild** [**-help**] [**-version**] _file_ [**-auto** | **-noauto**] [**-list** | **-nolist**] [**-realsize** | **-norealsize**] [**-headers** | **-noheaders**] [**-directives** | **-nodirectives**] [**-rfc934mode** | **-norfc934mode**] [**-contentid** | **-nocontentid**] [**-verbose** | **-noverbose**] [**-disposition** | **-nodisposition**] [**-check** | **-nocheck**] [**-headerencoding** _encoding-algorithm_ | **-autoheaderencoding**] [**-max**‐‐ **unencoded** _line-length_] [**-dist**] ## DESCRIPTION The **mhbuild** command will translate a MIME composition draft into a valid MIME message. **mhbuild** creates multi-media messages as specified in RFCs 2045 through 2049. This includes the encoding of message headers as specified by RFC 2047, and, additionally, the encoding of MIME parameters as specified in RFC 2231. If you specify the name of the composition file as “-”, then **mhbuild** will accept the composi‐ tion draft on the standard input. If the translation of this input is successful, **mhbuild** will output the new MIME message to the standard output. This argument must be the last ar‐ gument on the command line. Otherwise, if the file argument to **mhbuild** is the name of a valid composition file, and the translation is successful, **mhbuild** will replace the original file with the new MIME message. It will rename the original file to start with the “,” character and end with the string “.orig”, e.g., if you are editing the file “draft”, it will be renamed to “,draft.orig”. This allows you to easily recover the **mhbuild** input file. ### Listing the Contents The **-list** switch tells **mhbuild** to list the table of contents associated with the MIME message that is created. The **-headers** switch indicates that a one-line banner should be displayed above the listing. The **-realsize** switch tells **mhbuild** to evaluate the “native” (decoded) format of each content prior to listing. This provides an accurate count at the expense of a small delay. If the ### -verbose present in the message, such as comments in the “Content-Type” header. If the **-disposition** switch is present, then the listing will show any relevant information from the “Content-Disposition” header. ### Simplified Attachment Interface For users who wish to simply attach files to text content, **mhbuild** will scan the composition file for “Attach” headers. An “Attach” header contains a filename that will be appended to the message using normal MIME encapsulation rules. One filename is allowed per “Attach” header, but multiple “Attach” headers are allowed per composition file. These files will be appended after any other MIME content, including any content specified by **mhbuild** directives (see below). See [_send_(1)](https://www.chedong.com/phpMan.php/man/send/1/markdown) for more details. By default, the Content-Disposition will be “attachment”. **mhbuild** looks for user profile and _mhn.defaults_ entries of the form **mhbuild-disposition-**_type_**/**_subtype_ or **mhbuild-disposition-**_type_ to supply the disposition value. The only supported values are “attachment” and “inline”. ### Convert Interface The convert interface is a powerful mechanism that supports replying to MIME messages. These placeholders are used in the following description: TYPE content type/subtype CONVERTER external program, and any fixed arguments, to convert content, such as from a request to a reply ARGSTRING arguments to pass from **repl** to _CONVERTER_ FILE full path of message being replied to The convert support is based on pseudoheaders of the form **Nmh-mhbuild-file-**_TYPE_**:** _FILE_ **Nmh-mhbuild-args-**_TYPE_**:** _ARGSTRING_ in the draft. For each such pseudoheader, mhbuild looks in the profile and _mhn.defaults_ for the corresponding _TYPE_ entry to find the converter that supports it: **mhbuild-convert-**_TYPE_**:** _CONVERTER_ It's a fatal error if no such entry is found for _TYPE_. An empty entry, e.g., **mhbuild-convert-text/html:** excludes parts of that _TYPE_ from the draft. The _mhn.defaults_ file contains default **mhbuild-convert-text/html** and **mhbuild-convert-** **text/plain** entries. Profile entries can be used to override corresponding _mhn.defaults_ en‐ tries, as usual. Text converters should limit text line lengths to a maximum of 78 charac‐ ters, and must limit them to a maximum of 998 characters, per RFC 5322 Sec. 2.1.1. For each _TYPE_ part in _FILE_, **mhbuild** runs _CONVERTER_ _ARGSTRING_ on the content of the part. Each part in _FILE_ that has no corresponding TYPE entry in the profile or _mhn.defaults_ is ex‐ cluded from the draft; the user can include them using mhbuild directives. **repl** inserts **Nmh-mhbuild-text/html:** and **Nmh-mhbuild-text/plain:** pseudoheaders in every draft. The user can prevent insertion of content parts of either of those types by putting corre‐ sponding empty entries in their profile. Only the highest precedence alternative with a supported _TYPE_ of a multipart/alternative part is used. mhn.defaults.sh selects the text/html-to-text/plain converter at install time. It includes **iconv** and **par**, or **fmt**, in the pipeline only if they are found. Some content types require the addition of parameters to the Content-Type header, such as “method=REPLY” for text/calendar. **mhbuild** looks for a Content-Type header, followed by a blank line, at the beginning of the converter output. If one is found, it is used for the corresponding part in the reply draft. The convert interface doesn't support different _ARGSTRING_s or different converters for dif‐ ferent parts of the same _TYPE_. That would require associating parts by part number with the _ARGSTRING_s or converters. Instead, that can be done (currently, without using the convert support), with **mhbuild** directives as described below, e.g., #text/html; charset=utf-8 *8bit | mhstore -noverbose -part 42.7 -outfile - | w3m -dump -cols 64 -T text/html -O utf-8 The only way to mix convert pseudoheaders and **mhbuild** directives is to insert the directives before **mhbuild** is run, which is typically done by entering _mime_ at the “What now?” prompt, or with an **-editor** **mhbuild** switch. These (optional) setup steps can make the convert support easier to use: 1) If the **par** program is installed on your system, it will be set by default (in _mhn.de__‐ _faults_) to filter the converter output. It helps to set the PARINIT environment vari‐ able, as described in [_par_(1)](https://www.chedong.com/phpMan.php/man/par/1/markdown). 2) Add this line to your profile: mhbuild-next: $EDITOR assuming that your EDITOR environment variable is set; if not, replace EDITOR with the name of your editor. Without that profile entry, a response of “e[dit]” at the What now? prompt will require specification of your editor if an **-editor** **mhbuild** switch is used. 3) If using **repl**, source the Bourne-shell compatible functions in _/usr/share/doc/nmh/con__‐ _trib/replaliases_. That script also sets the PARINIT environment variable if it was not set. ### Translating the Composition File **mhbuild** is essentially a filter to aid in the composition of MIME messages. **mhbuild** will convert an **mhbuild** “composition file” into a valid MIME message. An **mhbuild** “composition file” is just a file containing plain text that is interspersed with various **mhbuild** direc‐ tives. When this file is processed by **mhbuild**, the various directives will be expanded to the appropriate content, and will be encoded according to the MIME standards. The resulting MIME message can then be sent by electronic mail. The formal syntax for a **mhbuild** composition file is defined at the end of this document, but the ideas behind this format are not complex. Basically, the body contains one or more con‐ tents. A content consists of either a directive, indicated with a “#” as the first character of a line; or, plaintext (one or more lines of text). The continuation character, “\“, may be used to enter a single directive on more than one line, e.g., #image/png \ /home/foobar/junk/picture.png There are five kinds of directives: “type” directives, which name the type and subtype of the content; “external-type” directives, which also name the type and subtype of the content; the “message” directive (#forw), which is used to forward one or more messages; the “begin” di‐ rective (#begin), which is used to create a multipart content; and the “on/off/pop” direc‐ tives (#on, #off, #pop) which control whether any other directives are honored at all. The **-directives** switch allows control over whether mhbuild will honor any of the “#”-direc‐ tives. This can also be affected with the #on or #off directives, and #pop, which restores the state of processing to that preceding the most recent #on or #off. (The #on, #off, and #pop directives are always honored, of course.) This allows inclusion of plain text which looks like mhbuild directives, without causing errors: #off #include printf("Hello, World!"); #pop Currently the stack depth for the #on/off/pop directives is 32. The “type” directive is used to directly specify the type and subtype of a content. You may only specify discrete types in this manner (can't specify the types multipart or message with this directive). You may optionally specify the name of a file containing the contents in “native” (decoded) format. If this filename starts with the “|” character, then it repre‐ sents a command to execute whose output is captured accordingly. For example, #audio/basic |raw2audio -F < /usr/lib/sound/giggle.au If a filename is not given, **mhbuild** will look for information in the user's profile to deter‐ mine how the different contents should be composed. This is accomplished by consulting a composition string, and executing it under **/bin/sh**, with the standard output set to the con‐ tent. If the **-verbose** switch is given, **mhbuild** will echo any commands that are used to cre‐ ate contents in this way. The composition string may contain the following escapes: %a Insert parameters from directive %f Insert filename containing content %F %f, and stdout is not re-directed %s Insert content subtype %% Insert character % First, **mhbuild** will look for an entry of the form: **mhbuild-compose-**_type_**/**_subtype_ to determine the command to use to compose the content. If this isn't found, **mhbuild** will look for an entry of the form: **mhbuild-compose-**_type_ to determine the composition command. If this isn't found, **mhbuild** will complain. An example entry might be: mhbuild-compose-audio/basic: record | raw2audio -F Because commands like these will vary, depending on the display environment used for login, composition strings for different contents should probably be put in the file specified by the MHBUILD environment variable, instead of directly in your user profile. The “external-type” directives are used to provide a MIME reference to a content, rather than enclosing the contents itself (for instance, by specifying an ftp site). Hence, instead of providing a filename as with the type directives, external-parameters are supplied. These look like regular parameters, so they must be separated accordingly. For example, #@application/octet-stream; \ type=tar; \ conversions=compress \ [this is the nmh distribution] \ {attachment; filename="nmh.tar.gz"} \ name="nmh.tar.gz"; \ directory="/pub/nmh"; \ site="ftp.math.gatech.edu"; \ access-type=anon-ftp; \ mode="image" You must give a description string to separate the content parameters from the external-pa‐ rameters (although this string may be empty). This description string is specified by en‐ closing it within “[]”. A disposition string, to appear in a “Content-Disposition” header, may appear in the optional “{}”. These parameters are of the form: access-type= usually “anon-ftp”, “mail-server”, or “url” name= filename permission= read-only or read-write site= hostname directory= directoryname (optional) mode= usually “ascii” or “image” (optional) size= number of octets server= mailbox subject= subject to send body= command to send for retrieval url= URL of content A minimum “external-type” directive for the **url** _access-type_ would be as follows: #@application/octet-stream [] access-type=url; \ url="" Any long URLs will be wrapped according to RFC 2231 rules. The “message” directive (#forw) is used to specify a message or group of messages to include. You may optionally specify the name of the folder and which messages are to be forwarded. If a folder is not given, it defaults to the current folder. Similarly, if a message is not given, it defaults to the current message. Hence, the message directive is similar to the **forw** command, except that the former uses the MIME rules for encapsulation rather than those specified in RFC 934. For example, #forw +inbox 42 43 99 If you include a single message, it will be included directly as a content of type “mes‐ sage/rfc822”. If you include more than one message, then **mhbuild** will add a content of type “multipart/digest” and include each message as a subpart of this content. If you are using this directive to include more than one message, you may use the **-rfc934mode** switch. This switch will indicate that **mhbuild** should attempt to utilize the MIME encapsula‐ tion rules in such a way that the “multipart/digest” that is created is (mostly) compatible with the encapsulation specified in RFC 934. If given, then RFC 934 compliant user-agents should be able to burst the message on reception -- providing that the messages being encap‐ sulated do not contain encapsulated messages themselves. The drawback of this approach is that the encapsulations are generated by placing an extra newline at the end of the body of each message. The “begin” directive is used to create a multipart content. When using the “begin” direc‐ tive, you must specify at least one content between the begin and end pairs. #begin This will be a multipart with only one part. #end If you use multiple directives in a composition draft, **mhbuild** will automatically encapsulate them inside a multipart content. Therefore the “begin” directive is only necessary if you wish to use nested multiparts, or create a multipart message containing only one part. For all of these directives, the user may include a brief description of the content between the “[” character and the “]” character. This description will be copied into the “Content- Description” header when the directive is processed. #forw [important mail from Bob] +bob 1 2 3 4 5 Similarly, a disposition string may optionally be provided between “{” and “}” characters; it will be copied into the “Content-Disposition” header when the directive is processed. If a disposition string is provided that does not contain a filename parameter, and a filename is provided in the directive, it will be added to the “Content-Disposition” header. For exam‐ ple, the following directive: #text/plain; charset=iso-8859-1 <>{attachment} /tmp/summary.txt creates these message part headers: Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: attachment; filename="summary.txt" By default, **mhbuild** will generate a unique “Content-ID:” for each directive, corresponding to each message part; however, the user may override this by defining the ID using the “<” and “>” characters. The **-nocontentid** switch suppresses creation of all “Content-ID:” headers, even in the top level of the message. Normally **mhbuild** will choose an appropriate Content-Transfer-Encoding based on the content and the MIME Content-Type. However, you can override that in an **mhbuild** directive by speci‐ fying “*” and the encoding. Acceptable encoding values are “8bit”, “qp” (for quoted-print‐ able), and “b64” (for base64 encoding). It should be noted that undesired results may occur if 8bit or quoted-printable is selected for binary content, due to the translation between Unix line endings and the line endings use by the mail transport system. In addition to the various directives, plaintext can be present. Plaintext is gathered, un‐ til a directive is found or the draft is exhausted, and this is made to form a text content. If the plaintext must contain a “#” at the beginning of a line, simply double it, e.g., ##when sent, this line will start with only one # If you want to end the plaintext prior to a directive, e.g., to have two plaintext contents adjacent, simply insert a line containing a single “#” character, e.g., this is the first content # and this is the second Finally, if the plaintext starts with a line of the form: Content-Description: text then this will be used to describe the plaintext content. You MUST follow this line with a blank line before starting your text. By default, plaintext is captured as a text/plain content. You can override this by starting the plaintext with “#<” followed by a content-type specification. For example, e.g., # cc: Subject: Look and listen to me! -------- The first part will be text/plain #" ] [ "[" description "]" ] [ "{" disposition "}" ] [ "*8bit" | "*qp" | "*b64" ] [ filename ] EOL | "#@" type "/" subtype 0*(";" attribute "=" value) [ "(" comment ")" ] [ "<" id ">" ] [ "[" description "]" ] [ "{" disposition "}" ] [ "*8bit" | "*qp" | "*b64" ] external-parameters EOL | "#forw" [ "<" id ">" ] [ "[" description "]" ] [ "{" disposition "}" ] [ "+"folder ] [ 0*msg ] EOL | "#begin" [ "<" id ">" ] [ "[" description "]" ] [ "{" disposition "}" ] [ "alternative" | "parallel" | something-else ] EOL 1*body "#end" EOL plaintext ::= [ "Content-Description:" description EOL EOL ] 1*line [ "#" EOL ] | "#<" type "/" subtype 0*(";" attribute "=" value) [ "(" comment ")" ] [ "[" description "]" ] [ "{" disposition "}" ] [ "*8bit" | "*qp" | "*b64" ] EOL 1*line [ "#" EOL ] line ::= "##" text EOL -- interpreted as "#"text EOL | text EOL ## FILES **mhbuild** looks for additional user profile files and _mhn.defaults_ in multiple locations: abso‐ lute pathnames are accessed directly, tilde expansion is done on usernames, and files are searched for in the user's _Mail_ directory as specified in their profile. If not found there, the directory “_/etc/nmh_” is checked. $HOME/.mh_profile The user's profile. $MHBUILD Additional profile entries. /etc/nmh/mhn.defaults System default MIME profile entries. ## PROFILE COMPONENTS Path: To determine the user's nmh directory. Current-Folder: To find the default current folder. mhbuild-compose-_type*_: Template for composing contents. ## SEE ALSO [_mhlist_(1)](https://www.chedong.com/phpMan.php/man/mhlist/1/markdown), [_mhshow_(1)](https://www.chedong.com/phpMan.php/man/mhshow/1/markdown), [_mhstore_(1)](https://www.chedong.com/phpMan.php/man/mhstore/1/markdown) _Multipurpose_ _Internet_ _Mail_ _Extensions_ _(MIME)_ _Part_ _One:_ _Format_ _of_ _Internet_ _Message_ _Bodies_ (RFC 2045) _Multipurpose_ _Internet_ _Mail_ _Extensions_ _(MIME)_ _Part_ _Two:_ _Media_ _Types_ (RFC 2046) _Multipurpose_ _Internet_ _Mail_ _Extensions_ _(MIME)_ _Part_ _Three:_ _Message_ _Header_ _Extensions_ _for_ _Non-_ _ASCII_ _Text_ (RFC 2047) _Internet_ _Message_ _Format_ (RFC 5322) _MIME_ _Parameter_ _Value_ _and_ _Encoded_ _Word_ _Extensions:_ _Character_ _Sets,_ _Languages,_ _and_ _Continua__‐ _tions_ (RFC 2231) _Proposed_ _Standard_ _for_ _Message_ _Encapsulation_ (RFC 934) _The_ _Content-MD5_ _Header_ _Field_ (RFC 1864) _Definition_ _of_ _the_ _URL_ _MIME_ _External-Body_ _Access-Type_ (RFC 2017) _Overview_ _and_ _Framework_ _for_ _Internationalized_ _Email_ (RFC 6530) _SMTP_ _Extension_ _for_ _Internationalized_ _Email_ (RFC 6531) ## DEFAULTS ### -autoheaderencoding ### -contentid ### -headers -maxunencoded 78 ### -nocheck ### -nodisposition ### -norfc934mode ### -noverbose ### -realsize nmh-1.7.1 2016-10-15 [MHBUILD(1mh)](https://www.chedong.com/phpMan.php/man/MHBUILD/1mh/markdown)