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   1 .TH MHBUILD %manext1% "January 4, 2013" "%nmhversion%"
   2 .\"
   3 .\" %nmhwarning%
   4 .\"
   5 .SH NAME
   6 mhbuild \- translate MIME composition draft
   7 .SH SYNOPSIS
   8 .na
   9 .HP 5
  10 .B mhbuild
  11 .I file
  12 .RB [ \-list " | " \-nolist ]
  13 .RB [ \-realsize " | " \-norealsize ]
  14 .RB [ \-headers " | " \-noheaders ]
  15 .RB [ \-directives " | " \-nodirectives ]
  16 .RB [ \-rfc934mode " | " \-norfc934mode ]
  17 .RB [ \-contentid " | " \-nocontentid ]
  18 .RB [ \-verbose " | " \-noverbose ]
  19 .RB [ \-check " | " \-nocheck ]
  20 .RB [ \-version ]
  21 .RB [ \-help ]
  22 .ad
  23 .SH DESCRIPTION
  24 The
  25 .B mhbuild
  26 command will translate a MIME composition draft into
  27 a valid MIME message.
  28 .PP
  29 .B mhbuild
  30 creates multi-media messages as specified in RFC\-2045
  31 thru RFC\-2049.  Currently
  32 .B mhbuild
  33 only supports encodings in
  34 message bodies, and does not support the encoding of message headers as
  35 specified in RFC\-2047.
  36 .PP
  37 If you specify the name of the composition file as \*(lq-\*(rq,
  38 then
  39 .B mhbuild
  40 will accept the composition draft on the standard
  41 input.  If the translation of this input is successful,
  42 .B mhbuild
  43 will output the new MIME message to the standard output.  This argument
  44 must be the last argument on the command line.
  45 .PP
  46 Otherwise if the file argument to
  47 .B mhbuild
  48 is the name of a valid
  49 composition file, and the translation is successful,
  50 .B mhbuild
  51 will replace the original file with the new MIME message.  It will rename
  52 the original file to start with the \*(lq,\*(rq character and end with the
  53 string \*(lq.orig\*(rq, e.g., if you are editing the file \*(lqdraft\*(rq,
  54 it will be renamed to \*(lq,draft.orig\*(rq.  This allows you to easily
  55 recover the
  56 .B mhbuild
  57 input file.
  58 .SS "Listing the Contents"
  59 The
  60 .B \-list
  61 switch tells
  62 .B mhbuild
  63 to list the table of contents associated with the MIME message that is created.
  64 .PP
  65 The
  66 .B \-headers
  67 switch indicates
  68 that a one-line banner should be displayed above the listing.  The
  69 .B \-realsize
  70 switch tells
  71 .B mhbuild
  72 to evaluate the \*(lqnative\*(rq
  73 (decoded) format of each content prior to listing.  This provides an
  74 accurate count at the expense of a small delay.  If the
  75 .B \-verbose
  76 switch
  77 is present, then the listing will show any \*(lqextra\*(rq information
  78 that is present in the message, such as comments in the
  79 \*(lqContent-Type\*(rq header.
  80 .SS "Translating the Composition File"
  81 .B mhbuild
  82 is essentially a filter to aid in the composition of MIME
  83 messages.
  84 .B mhbuild
  85 will convert an
  86 .B mhbuild
  87 \*(lqcomposition file\*(rq
  88 into a valid MIME message.  A
  89 .B mhbuild
  90 \*(lqcomposition file\*(rq
  91 is just a file containing plain text that is interspersed
  92 with various
  93 .B mhbuild
  94 directives.  When this file is processed
  95 by
  96 .BR mhbuild ,
  97 the various directives will be expanded to the
  98 appropriate content, and will be encoded according to the MIME standards.
  99 The resulting MIME message can then be sent by electronic mail.
 100 .PP
 101 The formal syntax for a
 102 .B mhbuild
 103 composition file is defined at the
 104 end of this document, but the ideas behind this format are not complex.
 105 Basically, the body contains one or more contents.  A content consists of
 106 either a directive, indicated with a \*(lq#\*(rq as the first character
 107 of a line; or, plaintext (one or more lines of text).  The continuation
 108 character, \*(lq\\\*(lq, may be used to enter a single directive on more
 109 than one line, e.g.,
 110 .PP
 111 .RS 5
 112 .nf
 113 #image/png \\
 114     /home/foobar/junk/picture.png
 115 .fi
 116 .RE
 117 .PP
 118 There are five kinds of directives: \*(lqtype\*(rq directives, which
 119 name the type and subtype of the content; \*(lqexternal-type\*(rq
 120 directives, which also name the type and subtype of the content; the
 121 \*(lqmessage\*(rq directive (#forw), which is used to forward one or
 122 more messages; the \*(lqbegin\*(rq directive (#begin), which is
 123 used to create a multipart content; and the \*(lqon/off/pop\*(rq
 124 directives (#on, #off, #pop) which control whether any other
 125 directives are honored at all.
 126 .PP
 127 The
 128 .B \-directives
 129 switch allows control over whether mhbuild will honor any of the
 130 \*(lq#\*(rq-directives.  This can also be affected with the #on or
 131 #off directives, and #pop, which restores the state of processing to
 132 that preceding the most recent #on or #off.  (The #on, #off, and #pop
 133 directives are always honored, of course.) This allows inclusion of
 134 plain text which looks like mhbuild directives, without causing
 135 errors:
 136 .PP
 137 .RS 5
 138 .nf
 139 #off
 140 #include <stdio.h>
 141 printf("Hello, World!);
 142 #pop
 143 .fi
 144 .RE
 145 .PP
 146 Currently the stack depth for the #on/off/pop directives is 32.
 147 .PP
 148 The \*(lqtype\*(rq directive is used to directly specify the type and
 149 subtype of a content.  You may only specify discrete types in this manner
 150 (can't specify the types multipart or message with this directive).
 151 You may optionally specify the name of a file containing the contents
 152 in \*(lqnative\*(rq (decoded) format.  If this filename starts with the
 153 \*(lq|\*(rq character, then it represents a command to execute whose
 154 output is captured accordingly.
 155 For example,
 156 .PP
 157 .RS 5
 158 .nf
 159 #audio/basic |raw2audio -F < /usr/lib/sound/giggle.au
 160 .fi
 161 .RE
 162 .PP
 163 If a filename is not given,
 164 .B mhbuild
 165 will look for information in the
 166 user's profile to determine how the different contents should be composed.
 167 This is accomplished by consulting a composition string, and executing
 168 it under
 169 .BR /bin/sh ,
 170 with the standard output set to the content.
 171 If the
 172 .B \-verbose
 173 switch is given,
 174 .B mhbuild
 175 will echo any commands that are used to create contents in this way.
 176 .PP
 177 The composition string may contain the following escapes:
 178 .PP
 179 .RS 5
 180 .nf
 181 .ta \w'%P  'u
 182 %a      Insert parameters from directive
 183 %f      Insert filename containing content
 184 %F      %f, and stdout is not re-directed
 185 %s      Insert content subtype
 186 %%      Insert character %
 187 .fi
 188 .RE
 189 .PP
 190 First,
 191 .B mhbuild
 192 will look for an entry of the form:
 193 .PP
 194 .RS 5
 195 mhbuild-compose-<type>/<subtype>
 196 .RE
 197 .PP
 198 to determine the command to use to compose the content.  If this isn't
 199 found,
 200 .B mhbuild
 201 will look for an entry of the form:
 202 .PP
 203 .RS 5
 204 mhbuild-compose-<type>
 205 .RE
 206 .PP
 207 to determine the composition command. If this isn't found,
 208 .B mhbuild
 209 will complain.
 210 .PP
 211 An example entry might be:
 212 .PP
 213 .RS 5
 214 mhbuild-compose-audio/basic: record | raw2audio -F
 215 .RE
 216 .PP
 217 Because commands like these will vary, depending on the display
 218 environment used for login, composition strings for different
 219 contents should probably be put in the file specified by the
 220 .B $MHBUILD
 221 environment variable, instead of directly in your
 222 user profile.
 223 .PP
 224 The \*(lqexternal-type\*(rq directives are used to provide a MIME
 225 reference to a content, rather than enclosing the contents itself
 226 (for instance, by specifying an ftp site).  Hence, instead of
 227 providing a filename as with the type directives, external-parameters
 228 are supplied.  These look like regular parameters, so they must be
 229 separated accordingly.  For example,
 230 .PP
 231 .RS 5
 232 .nf
 233 #@application/octet-stream; \\
 234     type=tar; \\
 235     conversions=compress \\
 236     [this is the nmh distribution] \\
 237     {application; filename="nmh.tar.gz"} \\
 238     name="nmh.tar.gz"; \\
 239     directory="/pub/nmh"; \\
 240     site="ftp.math.gatech.edu"; \\
 241     access-type=anon-ftp; \\
 242     mode="image"
 243 .fi
 244 .RE
 245 .PP
 246 You must give a description string to separate the content parameters
 247 from the external-parameters (although this string may be empty).
 248 This description string is specified by enclosing it within
 249 \*(lq[]\*(rq.  A disposition string, to appear in a
 250 \*(lqContent-Disposition\*(rq header, may appear in the optional
 251 \*(lq{}\*(rq.
 252 .PP
 253 These parameters are of the form:
 254 .PP
 255 .RS 5
 256 .nf
 257 .ta \w'access-type=  'u
 258 access-type=    usually \fIanon-ftp\fR or \fImail-server\fR
 259 name=   filename
 260 permission=     read-only or read-write
 261 site=   hostname
 262 directory=      directoryname (optional)
 263 mode=   usually \fIascii\fR or \fIimage\fR (optional)
 264 size=   number of octets
 265 server= mailbox
 266 subject=        subject to send
 267 body=   command to send for retrieval
 268 .fi
 269 .RE
 270 .PP
 271 The \*(lqmessage\*(rq directive (#forw) is used to specify a message or
 272 group of messages to include.  You may optionally specify the name of
 273 the folder and which messages are to be forwarded.  If a folder is not
 274 given, it defaults to the current folder.  Similarly, if a message is not
 275 given, it defaults to the current message.  Hence, the message directive
 276 is similar to the
 277 .B forw
 278 command, except that the former uses
 279 the MIME rules for encapsulation rather than those specified in RFC\-934.
 280 For example,
 281 .PP
 282 .RS 5
 283 .nf
 284 #forw +inbox 42 43 99
 285 .fi
 286 .RE
 287 .PP
 288 If you include a single message, it will be included directly as a content
 289 of type \*(lqmessage/rfc822\*(rq.  If you include more than one message,
 290 then
 291 .B mhbuild
 292 will add a content of type \*(lqmultipart/digest\*(rq
 293 and include each message as a subpart of this content.
 294 .PP
 295 If you are using this directive to include more than one message, you
 296 may use the
 297 .B \-rfc934mode
 298 switch.  This switch will indicate that
 299 .B mhbuild
 300 should attempt to utilize the MIME encapsulation rules
 301 in such a way that the \*(lqmultipart/digest\*(rq that is created
 302 is (mostly) compatible with the encapsulation specified in RFC\-934.
 303 If given, then RFC\-934 compliant user-agents should be able to burst the
 304 message on reception\0--\0providing that the messages being encapsulated
 305 do not contain encapsulated messages themselves.  The drawback of this
 306 approach is that the encapsulations are generated by placing an extra
 307 newline at the end of the body of each message.
 308 .PP
 309 The \*(lqbegin\*(rq directive is used to create a multipart content.
 310 When using the \*(lqbegin\*(rq directive, you must specify at least one
 311 content between the begin and end pairs.
 312 .PP
 313 .RS 5
 314 .nf
 315 #begin
 316 This will be a multipart with only one part.
 317 #end
 318 .fi
 319 .RE
 320 .PP
 321 If you use multiple directives in a composition draft,
 322 .B mhbuild
 323 will
 324 automatically encapsulate them inside a multipart content.  Therefore the
 325 \*(lqbegin\*(rq directive is only necessary if you wish to use nested
 326 multiparts, or create a multipart message containing only one part.
 327 .PP
 328 For all of these directives, the user may include a brief description
 329 of the content between the \*(lq[\*(rq character and the \*(lq]\*(rq
 330 character.  This description will be copied into the
 331 \*(lqContent-Description\*(rq header when the directive is processed.
 332 .PP
 333 .RS 5
 334 .nf
 335 #forw [important mail from Bob] +bob 1 2 3 4 5
 336 .fi
 337 .RE
 338 .PP
 339 Similarly, a disposition string may optionally be provided between
 340 \*(lq{\*(rq and \*(lq}\*(rq characters; it will be copied into the
 341 \*(lqContent-Disposition\*(rq header when the directive is processed.
 342 If a disposition string is provided that does not contain a filename
 343 parameter, and a filename is provided in the directive, it will be
 344 added to the \*(lqContent-Disposition\*(rq header.  For example, the
 345 following directive:
 346 .PP
 347 .RS 5
 348 .nf
 349 #text/plain; charset=iso-8859-1 <>{attachment} /tmp/summary.txt
 350 .fi
 351 .RE
 352 .PP
 353 creates these message part headers:
 354 .PP
 355 .RS 5
 356 .nf
 357 Content-Type: text/plain; charset="iso-8859-1"
 358 Content-Disposition: attachment; filename="summary.txt"
 359 .fi
 360 .RE
 361 .PP
 362 By default,
 363 .B mhbuild
 364 will generate a unique \*(lqContent-ID:\*(rq for each directive,
 365 corresponding to each message part; however, the user may override
 366 this by defining the ID using the \*(lq<\*(rq and \*(lq>\*(rq
 367 characters.  The
 368 .B \-nocontentid
 369 switch suppresses creation of all \*(lqContent-ID:\*(rq headers,
 370 even in the top level of the message.
 371 .PP
 372 In addition to the various directives, plaintext can be present.
 373 Plaintext is gathered, until a directive is found or the draft is
 374 exhausted, and this is made to form a text content.  If the plaintext
 375 must contain a \*(lq#\*(rq at the beginning of a line, simply double it,
 376 e.g.,
 377 .PP
 378 .RS 5
 379 ##when sent, this line will start with only one #
 380 .RE
 381 .PP
 382 If you want to end the plaintext prior to a directive, e.g., to have two
 383 plaintext contents adjacent, simply insert a line containing a single
 384 \*(lq#\*(rq character, e.g.,
 385 .PP
 386 .RS 5
 387 .nf
 388 this is the first content
 389 #
 390 and this is the second
 391 .fi
 392 .RE
 393 .PP
 394 Finally, if the plaintext starts with a line of the form:
 395 .PP
 396 .RS 5
 397 Content-Description: text
 398 .RE
 399 .PP
 400 then this will be used to describe the plaintext content.
 401 You MUST follow this line with a blank line before starting
 402 your text.
 403 .PP
 404 By default, plaintext is captured as a text/plain content.  You can
 405 override this by starting the plaintext with \*(lq#<\*(rq followed by
 406 a content-type specification.  For example, e.g.,
 407 .PP
 408 .RS 5
 409 .nf
 410 #<text/enriched
 411 this content will be tagged as text/enriched
 412 #
 413 and this content will be tagged as text/plain
 414 #
 415 #<application/x-patch [this is a patch]
 416 and this content will be tagged as application/x-patch
 417 .fi
 418 .RE
 419 .PP
 420 Note that if you use the \*(lq#<\*(rq plaintext-form, then the
 421 content-description must be on the same line which identifies the content
 422 type of the plaintext.
 423 .PP
 424 When composing a text content, you may indicate the relevant character
 425 set by adding the \*(lqcharset\*(rq parameter to the directive.
 426 .PP
 427 .RS 5
 428 #<text/plain; charset=iso-8859-5
 429 .RE
 430 .PP
 431 If a text content contains any 8\-bit characters (characters with the
 432 high bit set) and the character set is not specified as above, then
 433 .B mhbuild
 434 will assume the character set is of the type given by the
 435 environment variable MM_CHARSET.  If this environment variable is not
 436 set, then the character set will be labeled as \*(lqx-unknown\*(rq.
 437 .PP
 438 If a text content contains only 7\-bit characters and the character set
 439 is not specified as above, then the character set will be labeled as
 440 \*(lqus-ascii\*(rq.
 441 .PP
 442 Putting this all together,
 443 here is an example of a more complicated message draft.  The
 444 following draft will expand into a multipart/mixed message
 445 containing five parts:
 446 .PP
 447 .RS 5
 448 .nf
 449 To: nobody@nowhere.org
 450 cc:
 451 Subject: Look and listen to me!
 452 --------
 453 The first part will be text/plain
 454 #<text/enriched
 455 The second part will be text/enriched
 456 #
 457 This third part will be text/plain
 458 #audio/basic [silly giggle]  \\
 459     |raw2audio -F < /usr/lib/sounds/giggle.au
 460 #image/gif   [photo of foobar] \\
 461                     /home/foobar/lib/picture.gif
 462 .fi
 463 .RE
 464 .SS "Integrity Check"
 465 If
 466 .B mhbuild
 467 is given the
 468 .B \-check
 469 switch, then it will also associate an integrity check with each
 470 \*(lqleaf\*(rq content.  This will add a Content-MD5 header field to
 471 the content, along with the md5 sum of the unencoded contents, per RFC
 472 1864.  This may be used by the receiver of the message to verify that
 473 the contents of the message were not changed in transport.
 474 .SS "Transfer Encodings"
 475 After
 476 .B mhbuild
 477 constructs the new MIME message by parsing directives,
 478 including files, etc., it scans the contents of the message to determine
 479 which transfer encoding to use.  It will check for 8bit data, long lines,
 480 spaces at the end of lines, and clashes with multipart boundaries.  It will
 481 then choose a transfer encoding appropriate for each content type.
 482 .PP
 483 If an integrity check is being associated with each content by using
 484 the
 485 .B \-check
 486 switch, then
 487 .B mhbuild
 488 will encode each content with
 489 a transfer encoding, even it the content contains only 7\-bit data.  This
 490 is to increase the likelihood that the content is not changed while in
 491 transport.
 492 .SS "Invoking mhbuild"
 493 Typically,
 494 .B mhbuild
 495 is invoked by the
 496 .B whatnow
 497 program.  This
 498 command will expect the body of the draft to be formatted as an
 499 .B mhbuild
 500 composition file.  Once you have composed this input file
 501 using a command such as
 502 .BR comp ,
 503 .BR repl ,
 504 or
 505 .BR forw ,
 506 you invoke
 507 .B mhbuild
 508 at the \*(lqWhat now\*(rq prompt with
 509 .PP
 510 .RS 5
 511 What now? mime
 512 .RE
 513 .PP
 514 prior to sending the draft.  This will cause
 515 .B whatnow
 516 to execute
 517 .B mhbuild
 518 to translate the composition file into MIME format.
 519 .PP
 520 It is also possible to have the
 521 .B whatnow
 522 program invoke
 523 .B mhbuild
 524 automatically when a message is sent.  To do this, you must add the line
 525 .PP
 526 .RS 5
 527 automimeproc: 1
 528 .RE
 529 .PP
 530 to your
 531 .I \&.mh\(ruprofile
 532 file.
 533 .PP
 534 Finally, you should consider adding this line to your profile:
 535 .PP
 536 .RS 5
 537 lproc: show
 538 .RE
 539 .PP
 540 This way, if you decide to
 541 .B list
 542 after invoking
 543 .BR mime ,
 544 the command
 545 .PP
 546 .RS 5
 547 What now? list
 548 .RE
 549 .PP
 550 will work as you expect.
 551 .SS "User Environment"
 552 Because the environment in which
 553 .B mhbuild
 554 operates may vary for a
 555 user,
 556 .B mhbuild
 557 will look for the environment variable
 558 .BR $MHBUILD .
 559 If present, this specifies the name of an additional user profile which
 560 should be read.  Hence, when a user logs in on a particular machine,
 561 this environment variable should be set to refer to a file containing
 562 definitions useful for that machine.
 563 .PP
 564 Finally,
 565 .B mhbuild
 566 will attempt to consult a global
 567 .B mhbuild
 568 user profile, e.g.,
 569 .PP
 570 .RS 5
 571 %etcdir%/mhn.defaults
 572 .RE
 573 .PP
 574 if it exists.
 575 .SS "Syntax of Composition Files"
 576 The following is the formal syntax of a
 577 .B mhbuild
 578 \*(lqcomposition file\*(rq.
 579 .PP
 580 .RS 5
 581 .nf
 582 body         ::=     1*(content | EOL)
 583
 584 content      ::=     directive | plaintext
 585
 586 directive    ::=     "#" type "/" subtype
 587                          0*(";" attribute "=" value)
 588                          [ "(" comment ")" ]
 589                          [ "<" id ">" ]
 590                          [ "[" description "]" ]
 591                          [ "{" disposition "}" ]
 592                          [ filename ]
 593                          EOL
 594
 595                    | "#@" type "/" subtype
 596                          0*(";" attribute "=" value)
 597                          [ "(" comment ")" ]
 598                          [ "<" id ">" ]
 599                          [ "[" description "]" ]
 600                          [ "{" disposition "}" ]
 601                          external-parameters
 602                          EOL
 603
 604                    | "#forw"
 605                          [ "<" id ">" ]
 606                          [ "[" description "]" ]
 607                          [ "{" disposition "}" ]
 608                          [ "+"folder ] [ 0*msg ]
 609                          EOL
 610
 611                    | "#begin"
 612                            [ "<" id ">" ]
 613                            [ "[" description "]" ]
 614                            [ "{" disposition "}" ]
 615                            [   "alternative"
 616                              | "parallel"
 617                              | something-else    ]
 618                            EOL
 619                          1*body
 620                      "#end" EOL
 621
 622 plaintext    ::=     [ "Content-Description:"
 623                            description EOL EOL ]
 624                          1*line
 625                      [ "#" EOL ]
 626
 627                    | "#<" type "/" subtype
 628                          0*(";" attribute "=" value)
 629                          [ "(" comment ")" ]
 630                          [ "[" description "]" ]
 631                          [ "{" disposition "}" ]
 632                          EOL
 633                          1*line
 634                      [ "#" EOL ]
 635
 636 line         ::=     "##" text EOL
 637                      -- interpreted as "#"text EOL
 638                    | text EOL
 639 .fi
 640 .RE
 641 .SH FILES
 642 .fc ^ ~
 643 .nf
 644 .ta \w'%etcdir%/ExtraBigFileName  'u
 645 ^$HOME/\&.mh\(ruprofile~^The user profile
 646 ^$MHBUILD~^Additional profile entries
 647 ^%etcdir%/mhn.defaults~^System default MIME profile entries
 648 .fi
 649 .SH "PROFILE COMPONENTS"
 650 .fc ^ ~
 651 .nf
 652 .ta 2.4i
 653 .ta \w'ExtraBigProfileName  'u
 654 ^Path:~^To determine the user's nmh directory
 655 ^Current\-Folder:~^To find the default current folder
 656 ^mhbuild-compose-<type>*~^Template for composing contents
 657 .fi
 658 .SH "SEE ALSO"
 659 .IR mhlist (1),
 660 .IR mhshow (1),
 661 .IR mhstore (1)
 662 .PP
 663 .I "Proposed Standard for Message Encapsulation"
 664 (RFC\-934),
 665 .PP
 666 .I "The Content-MD5 Header Field"
 667 (RFC\-1864),
 668 .PP
 669 .I "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies"
 670 (RFC\-2045),
 671 .PP
 672 .I "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types"
 673 (RFC\-2046),
 674 .PP
 675 .I "Multipurpose Internet Mail Extensions (MIME) Part Three: Message Header Extensions for Non-ASCII Text"
 676 (RFC\-2047),
 677 .PP
 678 .I "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures"
 679 (RFC\-2048),
 680 .PP
 681 .I "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples"
 682 (RFC\-2049)
 683 .SH DEFAULTS
 684 .nf
 685 .RB ` \-headers '
 686 .RB ` \-realsize '
 687 .RB ` \-norfc934mode '
 688 .RB ` \-contentid '
 689 .RB ` \-nocheck '
 690 .RB ` \-noverbose '
 691 .fi