| rev |
line source |
|
meillo@58
|
1 .H0 "Discussion
|
|
meillo@0
|
2 .P
|
|
meillo@58
|
3 This main chapter discusses the practical work done in the mmh project.
|
|
meillo@58
|
4 It is structured along the goals to achieve. The concrete work done
|
|
meillo@58
|
5 is described in the examples of how the general goals were achieved.
|
|
meillo@87
|
6 The discussion compares the current version of mmh with the state of
|
|
meillo@87
|
7 nmh just before the mmh project started, i.e. Fall 2011.
|
|
meillo@87
|
8 Current changes of nmh will be mentioned only as side notes.
|
|
meillo@87
|
9 .\" XXX where do I discuss the parallel development of nmh?
|
|
meillo@58
|
10
|
|
meillo@58
|
11
|
|
meillo@58
|
12
|
|
meillo@58
|
13 .H1 "Stream-lining
|
|
meillo@58
|
14
|
|
meillo@0
|
15 .P
|
|
meillo@58
|
16 MH had been considered an all-in-one system for mail handling.
|
|
meillo@58
|
17 The community around nmh has a similar understanding.
|
|
meillo@87
|
18 In fundamental difference, mmh shall be a MUA only.
|
|
meillo@87
|
19 I believe that the development of all-in-one mail systems is obsolete.
|
|
meillo@87
|
20 Today, email is too complex to be fully covered by single projects.
|
|
meillo@87
|
21 Such a project won't be able to excel in all aspects.
|
|
meillo@87
|
22 Instead, the aspects of email should be covered my multiple projects,
|
|
meillo@87
|
23 which then can be combined to form a complete system.
|
|
meillo@87
|
24 Excellent implementations for the various aspects of email exist already.
|
|
meillo@87
|
25 Just to name three examples: Postfix is a specialized MTA,
|
|
meillo@87
|
26 Procmail is a specialized MDA, and Fetchmail is a specialized MRA.
|
|
meillo@89
|
27 I believe that it is best to use such specialized tools instead of
|
|
meillo@87
|
28 providing the same function again as a side-component in the project.
|
|
meillo@58
|
29 .P
|
|
meillo@87
|
30 Doing something well, requires to focus on a small set of specific aspects.
|
|
meillo@87
|
31 Under the assumption that focused development produces better results
|
|
meillo@87
|
32 in the particular area, specialized projects will likely be superior
|
|
meillo@87
|
33 in their field of focus.
|
|
meillo@87
|
34 Hence, all-in-one mail system projects \(en no matter if monolithic
|
|
meillo@87
|
35 or modular \(en will never be the best choice in any of the fields.
|
|
meillo@87
|
36 Even in providing the best consistent all-in-one system they are likely
|
|
meillo@87
|
37 to be beaten by projects that focus only on integrating existing mail
|
|
meillo@89
|
38 components to a homogeneous system.
|
|
meillo@87
|
39 .P
|
|
meillo@87
|
40 The limiting resource in Free Software community development
|
|
meillo@87
|
41 is usually man power.
|
|
meillo@87
|
42 If the development power is spread over a large development area,
|
|
meillo@87
|
43 it becomes even more difficult to compete with the specialists in the
|
|
meillo@87
|
44 various fields.
|
|
meillo@87
|
45 The concrete situation for MH-based mail systems is even tougher,
|
|
meillo@87
|
46 given the small and aged community, including both developers and users,
|
|
meillo@87
|
47 it has.
|
|
meillo@87
|
48 .P
|
|
meillo@87
|
49 In consequence, I believe that the available development resources
|
|
meillo@87
|
50 should be focused on the point where MH is most unique.
|
|
meillo@87
|
51 This is clearly the user interface \(en the MUA.
|
|
meillo@87
|
52 Peripheral parts should be removed to stream-line mmh for the MUA task.
|
|
meillo@60
|
53
|
|
meillo@60
|
54
|
|
meillo@87
|
55 .H2 "Removal of the Mail Transfer Facilities
|
|
meillo@60
|
56 .P
|
|
meillo@60
|
57 In contrast to nmh, which also provides mail submission and mail retrieval
|
|
meillo@87
|
58 agents, mmh is a MUA only.
|
|
meillo@66
|
59 This general difference in the view on the character of nmh
|
|
meillo@76
|
60 initiated the development of mmh.
|
|
meillo@66
|
61 Removing the mail transfer facilities had been the first work task
|
|
meillo@76
|
62 in the mmh project.
|
|
meillo@60
|
63 .P
|
|
meillo@66
|
64 The MSA is called \fIMessage Transfer Service\fP (MTS) in nmh.
|
|
meillo@76
|
65 The facility established network connections and spoke SMTP to submit
|
|
meillo@60
|
66 messages for relay to the outside world.
|
|
meillo@76
|
67 This part was implemented by the
|
|
meillo@60
|
68 .Pn post
|
|
meillo@60
|
69 command.
|
|
meillo@96
|
70 The changes in email in the last years
|
|
meillo@87
|
71 demanded changes in this part of nmh too.
|
|
meillo@89
|
72 Encryption and authentication for network connections
|
|
meillo@87
|
73 needed to be supported, hence TLS and SASL were introduced into nmh.
|
|
meillo@87
|
74 This added complexity to nmh without improving it in its core functions.
|
|
meillo@87
|
75 Also, keeping up with recent developments in the field of
|
|
meillo@87
|
76 mail transfer requires development power and specialists.
|
|
meillo@87
|
77 In mmh this whole facility was simply cut off.
|
|
meillo@76
|
78 .Ci f6aa95b724fd8c791164abe7ee5468bf5c34f226
|
|
meillo@76
|
79 .Ci fecd5d34f65597a4dfa16aeabea7d74b191532c3
|
|
meillo@76
|
80 .Ci 156d35f6425bea4c1ed3c4c79783dc613379c65b
|
|
meillo@87
|
81 Instead, mmh depends on an external MSA.
|
|
meillo@60
|
82 The only outgoing interface available to mmh is the
|
|
meillo@60
|
83 .Pn sendmail
|
|
meillo@87
|
84 command, which almost any MSA provides.
|
|
meillo@87
|
85 If not, a wrapper program can be written.
|
|
meillo@87
|
86 It must read the message from the standard input, extract the
|
|
meillo@87
|
87 recipient addresses from the message header, and hand the message
|
|
meillo@87
|
88 over to the MSA.
|
|
meillo@87
|
89 For example, a wrapper script for qmail would be:
|
|
meillo@87
|
90 .VS
|
|
meillo@87
|
91 #!/bin/sh
|
|
meillo@87
|
92 # ignore command line arguments
|
|
meillo@87
|
93 exec qmail-inject
|
|
meillo@87
|
94 VE
|
|
meillo@87
|
95 The requirement to parse the recipient addresses out of the message header
|
|
meillo@87
|
96 is likely to be removed in the future.
|
|
meillo@87
|
97 Then mmh would give the recipient addresses as command line arguments.
|
|
meillo@87
|
98 This is clearly the better interface, but mmh does not provide it yet.
|
|
meillo@87
|
99 .\" XXX implement it
|
|
meillo@60
|
100 .P
|
|
meillo@60
|
101 To retrieve mail, the
|
|
meillo@60
|
102 .Pn inc
|
|
meillo@76
|
103 command established network connections
|
|
meillo@76
|
104 and spoke POP3 to retrieve mail from remote servers.
|
|
meillo@76
|
105 As with mail submission, the network connections required encryption and
|
|
meillo@87
|
106 authentication, thus TLS and SASL were added.
|
|
meillo@87
|
107 Support for message retrieval through IMAP will become necessary
|
|
meillo@87
|
108 to be added soon, too, and so on for any changes in mail transfer.
|
|
meillo@76
|
109 Mmh has dropped the support for retrieving mail from remote locations.
|
|
meillo@76
|
110 .Ci ab7b48411962d26439f92f35ed084d3d6275459c
|
|
meillo@76
|
111 Instead, it depends on an external tool to cover this task.
|
|
meillo@87
|
112 In mmh there exist two paths for messages to enter mmh's mail storage:
|
|
meillo@87
|
113 (1) Mail can be incorporate with
|
|
meillo@60
|
114 .Pn inc
|
|
meillo@87
|
115 from the system maildrop, or (2) with
|
|
meillo@60
|
116 .Pn rcvstore
|
|
meillo@87
|
117 by reading them, one at a time, from the standard input.
|
|
meillo@60
|
118 .P
|
|
meillo@60
|
119 With the removal of the MSA and MRA, mmh converted from an all-in-one
|
|
meillo@87
|
120 mail system to being a MUA only.
|
|
meillo@87
|
121 Following the Unix philosophy, it now focuses on one job and
|
|
meillo@76
|
122 tries to do that one well.
|
|
meillo@76
|
123 Not only the programs follow that tenet but also the project itself does so.
|
|
meillo@60
|
124 Now, of course, mmh depends on third-party software.
|
|
meillo@87
|
125 An external MSA is required to transfer mail to the outside world;
|
|
meillo@60
|
126 an external MRA is required to retrieve mail from remote machines.
|
|
meillo@60
|
127 There exist excellent implementations of such software,
|
|
meillo@76
|
128 which do this specific task likely better than the internal
|
|
meillo@87
|
129 versions had done it.
|
|
meillo@87
|
130 Also, the best suiting programs can be freely chosen.
|
|
meillo@60
|
131 .P
|
|
meillo@60
|
132 As it had already been possible to use an external MSA or MRA,
|
|
meillo@60
|
133 why not keep the internal version for convenience?
|
|
meillo@76
|
134 The question whether there is sense in having a fall-back pager in all
|
|
meillo@76
|
135 the command line tools, for the cases when
|
|
meillo@60
|
136 .Pn more
|
|
meillo@60
|
137 or
|
|
meillo@60
|
138 .Pn less
|
|
meillo@76
|
139 aren't available, appears to be ridiculous.
|
|
meillo@87
|
140 Now, an MSA or MRA is more complex than a text pager
|
|
meillo@87
|
141 and not necessarily available but still the concept of orthogonal
|
|
meillo@87
|
142 design holds: ``Write programs that do one thing and do it well.''
|
|
meillo@87
|
143 .[
|
|
meillo@87
|
144 mcilroy unix phil
|
|
meillo@87
|
145 p. 53
|
|
meillo@87
|
146 .]
|
|
meillo@87
|
147 .[
|
|
meillo@87
|
148 mcilroy bstj foreword
|
|
meillo@87
|
149 .]
|
|
meillo@87
|
150 Here, this part of the Unix philosophy was applied not only
|
|
meillo@87
|
151 to the programs but to the project itself.
|
|
meillo@87
|
152 In other words:
|
|
meillo@87
|
153 ``Develop projects that focus on one thing and do it well.''
|
|
meillo@87
|
154 Projects grown complex should be split for the same reasons programs grown
|
|
meillo@87
|
155 complex should be split.
|
|
meillo@87
|
156 If it is conceptionally more elegant to have the MSA and MRA
|
|
meillo@87
|
157 separate projects then they should be separated.
|
|
meillo@87
|
158 This is the case here, in my opinion.
|
|
meillo@87
|
159 The RFCs propose this separation by clearly distinguishing the different
|
|
meillo@87
|
160 mail handling tasks.
|
|
meillo@87
|
161 .[
|
|
meillo@87
|
162 rfc 821
|
|
meillo@87
|
163 .]
|
|
meillo@87
|
164 The small interfaces between the mail agents support the separation.
|
|
meillo@76
|
165 .P
|
|
meillo@87
|
166 In the beginning, email had been small and simple.
|
|
meillo@76
|
167 (\c
|
|
meillo@60
|
168 .Pn /bin/mail
|
|
meillo@76
|
169 had once covered anything there was to email and still had been small
|
|
meillo@76
|
170 and simple.)
|
|
meillo@76
|
171 Then the essential complexity of email increased.
|
|
meillo@87
|
172 (Essential complexity is the complexity defined by the problem itself.\0
|
|
meillo@87
|
173 .[[
|
|
meillo@87
|
174 brooks no silver bullet
|
|
meillo@87
|
175 .]])
|
|
meillo@87
|
176 Email systems reacted to this change: They grew.
|
|
meillo@87
|
177 RFCs started to introduce mail agents and separated the various tasks
|
|
meillo@87
|
178 because the existing tasks became more extensive and new tasks appeared.
|
|
meillo@87
|
179 Again, email systems grew, or they split parts off.
|
|
meillo@76
|
180 In nmh, for instance, the POP server, which the original MH had included,
|
|
meillo@76
|
181 was removed.
|
|
meillo@87
|
182 Now is the time to go one step further and remove the MSA and MRA, too.
|
|
meillo@87
|
183 Not only does this decrease the code size of the project,
|
|
meillo@87
|
184 but, more important, it unburdens mmh of the whole field of
|
|
meillo@87
|
185 message transfer with all its implications for the project.
|
|
meillo@87
|
186 There's no more need to concern with changes in network transfer.
|
|
meillo@76
|
187 This independence is received by depending on an external program
|
|
meillo@76
|
188 that covers the field.
|
|
meillo@76
|
189 Today, this is a reasonable exchange.
|
|
meillo@60
|
190 .P
|
|
meillo@87
|
191 Function can be added in three different ways:
|
|
meillo@87
|
192 .BU
|
|
meillo@87
|
193 Implementing the function originally in the project.
|
|
meillo@87
|
194 .BU
|
|
meillo@87
|
195 Depending on a library that provides the function.
|
|
meillo@87
|
196 .BU
|
|
meillo@87
|
197 Depending on a program that provides the function.
|
|
meillo@87
|
198 .P
|
|
meillo@87
|
199 Whereas adding the function originally to the project increases the
|
|
meillo@76
|
200 code size most and requires most maintenance and development work,
|
|
meillo@87
|
201 it makes the project most independent of other software.
|
|
meillo@87
|
202 Using libraries or external programs require less maintenance work
|
|
meillo@87
|
203 but introduces dependencies on external software.
|
|
meillo@87
|
204 Programs have the smallest interfaces and provide the best separation
|
|
meillo@87
|
205 but possibly limit the information exchange.
|
|
meillo@87
|
206 External libraries are stronger connected than external programs,
|
|
meillo@87
|
207 thus information can be exchanged more flexible.
|
|
meillo@87
|
208 Adding code to a project increases maintenance work.
|
|
meillo@87
|
209 .\" XXX ref
|
|
meillo@87
|
210 Implementing complex functions originally in the project will add
|
|
meillo@87
|
211 a lot of code.
|
|
meillo@87
|
212 This should be avoided if possible.
|
|
meillo@66
|
213 Hence, the dependencies only change in kind, not in their existence.
|
|
meillo@66
|
214 In mmh, library dependencies on
|
|
meillo@66
|
215 .Pn libsasl2
|
|
meillo@66
|
216 and
|
|
meillo@66
|
217 .Pn libcrypto /\c
|
|
meillo@66
|
218 .Pn libssl
|
|
meillo@66
|
219 were treated against program dependencies on an MSA and an MRA.
|
|
meillo@87
|
220 This also meant treating build-time dependencies against run-time
|
|
meillo@87
|
221 dependencies.
|
|
meillo@66
|
222 Besides program dependencies providing the stronger separation
|
|
meillo@66
|
223 and being more flexible, they also allowed
|
|
meillo@66
|
224 over 6\|000 lines of code to be removed from mmh.
|
|
meillo@66
|
225 This made mmh's code base about 12\|% smaller.
|
|
meillo@87
|
226 Reducing the project's code size by such an amount without actually
|
|
meillo@87
|
227 losing functionality is a convincing argument.
|
|
meillo@87
|
228 Actually, as external MSAs and MRAs are likely superior to the
|
|
meillo@87
|
229 project's internal versions, the common user even gains functionality.
|
|
meillo@66
|
230 .P
|
|
meillo@76
|
231 Users of MH should not have problems to set up an external MSA and MRA.
|
|
meillo@60
|
232 Also, the popular MSAs and MRAs have large communities and a lot
|
|
meillo@60
|
233 of documentation available.
|
|
meillo@87
|
234 Choices for MSAs range from full-featured MTAs like
|
|
meillo@60
|
235 .I Postfix
|
|
meillo@87
|
236 over mid-size MTAs like
|
|
meillo@60
|
237 .I masqmail
|
|
meillo@60
|
238 and
|
|
meillo@60
|
239 .I dma
|
|
meillo@60
|
240 to small forwarders like
|
|
meillo@60
|
241 .I ssmtp
|
|
meillo@60
|
242 and
|
|
meillo@60
|
243 .I nullmailer .
|
|
meillo@60
|
244 Choices for MRAs include
|
|
meillo@60
|
245 .I fetchmail ,
|
|
meillo@60
|
246 .I getmail ,
|
|
meillo@60
|
247 .I mpop
|
|
meillo@60
|
248 and
|
|
meillo@60
|
249 .I fdm .
|
|
meillo@60
|
250
|
|
meillo@60
|
251
|
|
meillo@60
|
252 .H2 "Removal of non-MUA Tools
|
|
meillo@60
|
253 .P
|
|
meillo@87
|
254 One goal of mmh is to remove the tools that are not part of the MUA's task.
|
|
meillo@89
|
255 Further more, any tools that don't improve the MUA's job significantly
|
|
meillo@87
|
256 should be removed.
|
|
meillo@87
|
257 Loosely related and rarely used tools distract from the lean appearance.
|
|
meillo@87
|
258 They require maintenance work without adding much to the core task.
|
|
meillo@87
|
259 On removing these tools, the project shall become more stream-lined
|
|
meillo@87
|
260 and focused.
|
|
meillo@76
|
261 In mmh the following tools are not available anymore:
|
|
meillo@62
|
262 .BU
|
|
meillo@58
|
263 .Pn conflict
|
|
meillo@87
|
264 was removed
|
|
meillo@76
|
265 .Ci 8b235097cbd11d728c07b966cf131aa7133ce5a9
|
|
meillo@87
|
266 because it is a mail system maintenance tool that is not MUA-related.
|
|
meillo@87
|
267 It even checked
|
|
meillo@58
|
268 .Fn /etc/passwd
|
|
meillo@58
|
269 and
|
|
meillo@58
|
270 .Fn /etc/group
|
|
meillo@87
|
271 for consistency, which is completely unrelated to email.
|
|
meillo@87
|
272 A tool like
|
|
meillo@87
|
273 .Pn conflict
|
|
meillo@87
|
274 is surely useful, but it should not be shipped with mmh.
|
|
meillo@76
|
275 .\" XXX historic reasons?
|
|
meillo@62
|
276 .BU
|
|
meillo@58
|
277 .Pn rcvtty
|
|
meillo@87
|
278 was removed
|
|
meillo@87
|
279 .Ci 14767c94b3827be7c867196467ed7aea5f6f49b0
|
|
meillo@89
|
280 because its use case of writing to the user's terminal
|
|
meillo@76
|
281 on receiving of mail is obsolete.
|
|
meillo@87
|
282 If users like to be informed of new mail, the shell's
|
|
meillo@58
|
283 .Ev MAILPATH
|
|
meillo@87
|
284 variable or graphical notifications are technically more appealing.
|
|
meillo@62
|
285 Writing directly to a terminals is hardly ever wanted today.
|
|
meillo@62
|
286 If though one wants to have it this way, the standard tool
|
|
meillo@58
|
287 .Pn write
|
|
meillo@58
|
288 can be used in a way similar to:
|
|
meillo@82
|
289 .VS
|
|
meillo@58
|
290 scan -file - | write `id -un`
|
|
meillo@82
|
291 VE
|
|
meillo@62
|
292 .BU
|
|
meillo@58
|
293 .Pn viamail
|
|
meillo@87
|
294 was removed
|
|
meillo@87
|
295 .Ci eda72d6a7a7c20ff123043fb7f19c509ea01f932
|
|
meillo@87
|
296 when the new attachment system was activated, because
|
|
meillo@58
|
297 .Pn forw
|
|
meillo@76
|
298 could then cover the task itself.
|
|
meillo@62
|
299 The program
|
|
meillo@58
|
300 .Pn sendfiles
|
|
meillo@62
|
301 was rewritten as a shell script wrapper around
|
|
meillo@58
|
302 .Pn forw .
|
|
meillo@76
|
303 .Ci 0e82199cf3c991a173e0ac8aa776efdb3ded61e6
|
|
meillo@62
|
304 .BU
|
|
meillo@58
|
305 .Pn msgchk
|
|
meillo@87
|
306 was removed
|
|
meillo@87
|
307 .Ci bb9360ead7eb7a3fedcce2eeedfc660014e41dbe ,
|
|
meillo@87
|
308 because it lost its use case when POP support was removed.
|
|
meillo@76
|
309 A call to
|
|
meillo@58
|
310 .Pn msgchk
|
|
meillo@87
|
311 provided hardly more information than:
|
|
meillo@82
|
312 .VS
|
|
meillo@58
|
313 ls -l /var/mail/meillo
|
|
meillo@82
|
314 VE
|
|
meillo@87
|
315 It did distinguished between old and new mail, but
|
|
meillo@87
|
316 this detail information and can be retrieved with
|
|
meillo@76
|
317 .Pn stat (1),
|
|
meillo@62
|
318 too.
|
|
meillo@62
|
319 A very small shell script could be written to output the information
|
|
meillo@76
|
320 in a similar way, if truly necessary.
|
|
meillo@76
|
321 As mmh's
|
|
meillo@76
|
322 .Pn inc
|
|
meillo@87
|
323 only incorporates mail from the user's local maildrop,
|
|
meillo@62
|
324 and thus no data transfers over slow networks are involved,
|
|
meillo@76
|
325 there's hardly any need to check for new mail before incorporating it.
|
|
meillo@62
|
326 .BU
|
|
meillo@58
|
327 .Pn msh
|
|
meillo@87
|
328 was removed
|
|
meillo@76
|
329 .Ci 916690191222433a6923a4be54b0d8f6ac01bd02
|
|
meillo@87
|
330 because the tool was in conflict with the philosophy of MH.
|
|
meillo@76
|
331 It provided an interactive shell to access the features of MH,
|
|
meillo@76
|
332 but it wasn't just a shell, tailored to the needs of mail handling.
|
|
meillo@76
|
333 Instead it was one large program that had several MH tools built in.
|
|
meillo@76
|
334 This conflicts with the major feature of MH of being a tool chest.
|
|
meillo@76
|
335 .Pn msh 's
|
|
meillo@76
|
336 main use case had been accessing Bulletin Boards, which have seized to
|
|
meillo@62
|
337 be popular.
|
|
meillo@62
|
338 .P
|
|
meillo@62
|
339 Removing
|
|
meillo@58
|
340 .Pn msh ,
|
|
meillo@76
|
341 together with the truly archaic code relicts
|
|
meillo@58
|
342 .Pn vmh
|
|
meillo@58
|
343 and
|
|
meillo@58
|
344 .Pn wmh ,
|
|
meillo@62
|
345 saved more than 7\|000 lines of C code \(en
|
|
meillo@66
|
346 about 15\|% of the project's original source code amount.
|
|
meillo@76
|
347 .P
|
|
meillo@76
|
348 Having less code (with equal readability, of course)
|
|
meillo@76
|
349 for the same functionality is an advantage.
|
|
meillo@63
|
350 Less code means less bugs and less maintenance work.
|
|
meillo@76
|
351 As
|
|
meillo@63
|
352 .Pn rcvtty
|
|
meillo@63
|
353 and
|
|
meillo@63
|
354 .Pn msgchk
|
|
meillo@87
|
355 are assumed to be rarely used and can be implemented in different ways,
|
|
meillo@87
|
356 why should one keep them?
|
|
meillo@76
|
357 Removing them stream-lines mmh.
|
|
meillo@63
|
358 .Pn viamail 's
|
|
meillo@63
|
359 use case is now partly obsolete and partly covered by
|
|
meillo@63
|
360 .Pn forw ,
|
|
meillo@76
|
361 hence there's no reason to still maintain it.
|
|
meillo@63
|
362 .Pn conflict
|
|
meillo@76
|
363 is not related to the mail client, and
|
|
meillo@63
|
364 .Pn msh
|
|
meillo@63
|
365 conflicts with the basic concept of MH.
|
|
meillo@76
|
366 Theses two tools might still be useful, but they should not be part of mmh.
|
|
meillo@63
|
367 .P
|
|
meillo@76
|
368 Finally, there's
|
|
meillo@76
|
369 .Pn slocal .
|
|
meillo@76
|
370 .Pn slocal
|
|
meillo@76
|
371 is an MDA and thus not directly MUA-related.
|
|
meillo@78
|
372 It should be removed, because including it is a violation
|
|
meillo@78
|
373 of the idea that mmh is a MUA only.
|
|
meillo@78
|
374 It should become a separate project.
|
|
meillo@87
|
375 However,
|
|
meillo@76
|
376 .Pn slocal
|
|
meillo@76
|
377 provides rule-based processing of messages, like filing them into
|
|
meillo@76
|
378 different folders, which is otherwise not available in mmh.
|
|
meillo@87
|
379 Although
|
|
meillo@76
|
380 .Pn slocal
|
|
meillo@87
|
381 does neither pull in dependencies nor does it include a separate
|
|
meillo@87
|
382 technical area (cf. Sec. XXX),
|
|
meillo@87
|
383 still it accounts for about 1\|000 lines of code that need to be maintained.
|
|
meillo@76
|
384 As
|
|
meillo@76
|
385 .Pn slocal
|
|
meillo@76
|
386 is almost self-standing, it should be split off into a separate project.
|
|
meillo@76
|
387 This would cut the strong connection between the MUA mmh and the MDA
|
|
meillo@76
|
388 .Pn slocal .
|
|
meillo@87
|
389 For anyone not using MH,
|
|
meillo@87
|
390 .Pn slocal
|
|
meillo@87
|
391 would become yet another independent MDA, like
|
|
meillo@87
|
392 .I procmail .
|
|
meillo@87
|
393 The need to install a complete MH system to have
|
|
meillo@87
|
394 .Pn slocal
|
|
meillo@87
|
395 would be gone.
|
|
meillo@76
|
396 Likewise, mmh users could decide to use
|
|
meillo@76
|
397 .I procmail
|
|
meillo@87
|
398 without having a second, unused MDA,
|
|
meillo@87
|
399 .Pn slocal ,
|
|
meillo@76
|
400 installed.
|
|
meillo@76
|
401 That's conceptionally the best solution.
|
|
meillo@76
|
402 Yet,
|
|
meillo@76
|
403 .Pn slocal
|
|
meillo@87
|
404 is not split off.
|
|
meillo@87
|
405 I feel unsure with removing it from mmh.
|
|
meillo@87
|
406 Hence, I defer the decision over
|
|
meillo@87
|
407 .Pn slocal .
|
|
meillo@87
|
408 In the meanwhile
|
|
meillo@78
|
409 .Pn slocal
|
|
meillo@87
|
410 does not hurt because it is unrelated to the rest of mmh.
|
|
meillo@0
|
411
|
|
meillo@58
|
412
|
|
meillo@76
|
413 .H2 "\fLshow\fP and \fPmhshow\fP
|
|
meillo@58
|
414 .P
|
|
meillo@69
|
415 Since the very beginning \(en already in the first concept paper \(en
|
|
meillo@58
|
416 .Pn show
|
|
meillo@62
|
417 had been MH's message display program.
|
|
meillo@58
|
418 .Pn show
|
|
meillo@76
|
419 mapped message numbers and sequences to files and invoked
|
|
meillo@58
|
420 .Pn mhl
|
|
meillo@89
|
421 to have the files formatted.
|
|
meillo@88
|
422 With MIME, this approach wasn't sufficient anymore.
|
|
meillo@58
|
423 MIME messages can consist of multiple parts, some of which aren't
|
|
meillo@88
|
424 directly displayable, further more text content might be encoded in
|
|
meillo@58
|
425 foreign charsets.
|
|
meillo@58
|
426 .Pn show 's
|
|
meillo@76
|
427 understanding of messages and
|
|
meillo@58
|
428 .Pn mhl 's
|
|
meillo@88
|
429 display capabilities couldn't cope with the task any longer.
|
|
meillo@62
|
430 .P
|
|
meillo@88
|
431 Instead of extending these tools, additional tools were written from
|
|
meillo@88
|
432 scratch and added to the MH tool chest.
|
|
meillo@88
|
433 Doing so is encouraged by the tool chest approach.
|
|
meillo@88
|
434 Modular design is a great advantage for extending a system,
|
|
meillo@88
|
435 as new tools can be added without interfering with existing ones.
|
|
meillo@62
|
436 First, the new MIME features were added in form of the single program
|
|
meillo@58
|
437 .Pn mhn .
|
|
meillo@58
|
438 The command
|
|
meillo@82
|
439 .Cl "mhn -show 42
|
|
meillo@58
|
440 would show the MIME message numbered 42.
|
|
meillo@58
|
441 With the 1.0 release of nmh in February 1999, Richard Coleman finished
|
|
meillo@58
|
442 the split of
|
|
meillo@58
|
443 .Pn mhn
|
|
meillo@88
|
444 into a set of specialized tools, which together covered the
|
|
meillo@88
|
445 multiple aspects of MIME.
|
|
meillo@88
|
446 One of them was
|
|
meillo@69
|
447 .Pn mhshow ,
|
|
meillo@88
|
448 which replaced
|
|
meillo@88
|
449 .Cl "mhn -show" .
|
|
meillo@88
|
450 It was capable of displaying MIME messages appropriately.
|
|
meillo@62
|
451 .P
|
|
meillo@88
|
452 From then on, two message display tools were part of nmh,
|
|
meillo@76
|
453 .Pn show
|
|
meillo@76
|
454 and
|
|
meillo@76
|
455 .Pn mhshow .
|
|
meillo@88
|
456 To ease the life of users,
|
|
meillo@69
|
457 .Pn show
|
|
meillo@69
|
458 was extended to automatically hand the job over to
|
|
meillo@69
|
459 .Pn mhshow
|
|
meillo@69
|
460 if displaying the message would be beyond
|
|
meillo@69
|
461 .Pn show 's
|
|
meillo@69
|
462 abilities.
|
|
meillo@88
|
463 In consequence, the user would simply invoke
|
|
meillo@69
|
464 .Pn show
|
|
meillo@69
|
465 (possibly through
|
|
meillo@69
|
466 .Pn next
|
|
meillo@69
|
467 or
|
|
meillo@69
|
468 .Pn prev )
|
|
meillo@69
|
469 and get the message printed with either
|
|
meillo@69
|
470 .Pn show
|
|
meillo@69
|
471 or
|
|
meillo@69
|
472 .Pn mhshow ,
|
|
meillo@69
|
473 whatever was more appropriate.
|
|
meillo@69
|
474 .P
|
|
meillo@69
|
475 Having two similar tools for essentially the same task is redundant.
|
|
meillo@88
|
476 Usually,
|
|
meillo@88
|
477 users wouldn't distinguish between
|
|
meillo@88
|
478 .Pn show
|
|
meillo@88
|
479 and
|
|
meillo@88
|
480 .Pn mhshow
|
|
meillo@88
|
481 in their daily mail reading.
|
|
meillo@88
|
482 Having two separate display programs was therefore mainly unnecessary
|
|
meillo@88
|
483 from a user's point of view.
|
|
meillo@88
|
484 Besides, the development of both programs needed to be in sync,
|
|
meillo@76
|
485 to ensure that the programs behaved in a similar way,
|
|
meillo@76
|
486 because they were used like a single tool.
|
|
meillo@76
|
487 Different behavior would have surprised the user.
|
|
meillo@69
|
488 .P
|
|
meillo@69
|
489 Today, non-MIME messages are rather seen to be a special case of
|
|
meillo@88
|
490 MIME messages, although it's the other way round.
|
|
meillo@69
|
491 As
|
|
meillo@69
|
492 .Pn mhshow
|
|
meillo@88
|
493 had already be able to display non-MIME messages, it appeared natural
|
|
meillo@69
|
494 to drop
|
|
meillo@69
|
495 .Pn show
|
|
meillo@69
|
496 in favor of using
|
|
meillo@69
|
497 .Pn mhshow
|
|
meillo@69
|
498 exclusively.
|
|
meillo@88
|
499 .Ci 4c1efddfd499300c7e74263e57d8aa137e84c853
|
|
meillo@88
|
500 Removing
|
|
meillo@88
|
501 .Pn show
|
|
meillo@88
|
502 is no loss in function, because functionally
|
|
meillo@88
|
503 .Pn mhshow
|
|
meillo@88
|
504 covers it completely.
|
|
meillo@88
|
505 The old behavior of
|
|
meillo@88
|
506 .Pn show
|
|
meillo@88
|
507 can still be emulated with the simple command line:
|
|
meillo@88
|
508 .VS
|
|
meillo@88
|
509 mhl `mhpath c`
|
|
meillo@88
|
510 VE
|
|
meillo@88
|
511 .P
|
|
meillo@76
|
512 For convenience,
|
|
meillo@76
|
513 .Pn mhshow
|
|
meillo@88
|
514 was renamed to
|
|
meillo@88
|
515 .Pn show
|
|
meillo@88
|
516 after
|
|
meillo@88
|
517 .Pn show
|
|
meillo@88
|
518 was gone.
|
|
meillo@88
|
519 It is clear that such a rename may confuse future developers when
|
|
meillo@88
|
520 trying to understand the history.
|
|
meillo@88
|
521 Nevertheless, I consider the convenience on the user's side,
|
|
meillo@88
|
522 to call
|
|
meillo@88
|
523 .Pn show
|
|
meillo@88
|
524 when they want a message to be displayed, to outweigh the inconvenience
|
|
meillo@88
|
525 on the developer's side when understanding the project history.
|
|
meillo@69
|
526 .P
|
|
meillo@88
|
527 To prepare for the transition,
|
|
meillo@69
|
528 .Pn mhshow
|
|
meillo@69
|
529 was reworked to behave more like
|
|
meillo@69
|
530 .Pn show
|
|
meillo@69
|
531 first.
|
|
meillo@88
|
532 (cf. Sec. XXX)
|
|
meillo@88
|
533 Once the tools behaved more alike, the replacing appeared to be
|
|
meillo@88
|
534 even more natural.
|
|
meillo@88
|
535 Today, mmh's new
|
|
meillo@69
|
536 .Pn show
|
|
meillo@88
|
537 became the one single message display program again, with the difference
|
|
meillo@88
|
538 that today it handles MIME messages as well as non-MIME messages.
|
|
meillo@88
|
539 The outcome of the transition is one program less to maintain,
|
|
meillo@88
|
540 no second display program for users to deal with,
|
|
meillo@88
|
541 and less system complexity.
|
|
meillo@69
|
542 .P
|
|
meillo@88
|
543 Still, removing the old
|
|
meillo@69
|
544 .Pn show
|
|
meillo@88
|
545 hurts in one regard: It had been such a simple program.
|
|
meillo@88
|
546 Its lean elegance is missing to the new
|
|
meillo@69
|
547 .Pn show .
|
|
meillo@88
|
548 But there is no chance;
|
|
meillo@88
|
549 supporting MIME demands for higher essential complexity.
|
|
meillo@58
|
550
|
|
meillo@58
|
551
|
|
meillo@58
|
552 .H2 "Removal of Configure Options
|
|
meillo@58
|
553 .P
|
|
meillo@76
|
554 Customization is a double-edged sword.
|
|
meillo@76
|
555 It allows better suiting setups, but not for free.
|
|
meillo@76
|
556 There is the cost of code complexity to be able to customize.
|
|
meillo@76
|
557 There is the cost of less tested setups, because there are
|
|
meillo@72
|
558 more possible setups and especially corner-cases.
|
|
meillo@76
|
559 And, there is the cost of choice itself.
|
|
meillo@76
|
560 The code complexity directly affects the developers.
|
|
meillo@72
|
561 Less tested code affects both, users and developers.
|
|
meillo@76
|
562 The problem of choice affects the users, for once by having to
|
|
meillo@76
|
563 choose, but also by complexer interfaces that require more documentation.
|
|
meillo@72
|
564 Whenever options add little advantages, they should be considered for
|
|
meillo@72
|
565 removal.
|
|
meillo@72
|
566 I have reduced the number of project-specific configure options from
|
|
meillo@72
|
567 fifteen to three.
|
|
meillo@74
|
568
|
|
meillo@76
|
569 .U3 "Mail Transfer Facilities
|
|
meillo@74
|
570 .P
|
|
meillo@85
|
571 With the removal of the mail transfer facilities five configure
|
|
meillo@85
|
572 options vanished:
|
|
meillo@85
|
573 .P
|
|
meillo@85
|
574 The switches
|
|
meillo@85
|
575 .Sw --with-tls
|
|
meillo@85
|
576 and
|
|
meillo@85
|
577 .Sw --with-cyrus-sasl
|
|
meillo@89
|
578 had activated the support for transfer encryption and authentication.
|
|
meillo@85
|
579 This is not needed anymore.
|
|
meillo@85
|
580 .Ci fecd5d34f65597a4dfa16aeabea7d74b191532c3
|
|
meillo@85
|
581 .Ci 156d35f6425bea4c1ed3c4c79783dc613379c65b
|
|
meillo@85
|
582 .P
|
|
meillo@85
|
583 The configure switch
|
|
meillo@85
|
584 .Sw --enable-pop
|
|
meillo@85
|
585 activated the message retrieval facility.
|
|
meillo@85
|
586 The code area that would be conditionally compiled in for TLS and SASL
|
|
meillo@85
|
587 support had been small.
|
|
meillo@85
|
588 The conditionally compiled code area for POP support had been much larger.
|
|
meillo@85
|
589 Whereas the code base changes would only slightly change on toggling
|
|
meillo@85
|
590 TLS or SASL support, it changed much on toggling POP support.
|
|
meillo@85
|
591 The changes in the code base could hardly be overviewed.
|
|
meillo@85
|
592 By having POP support togglable a second code base had been created,
|
|
meillo@85
|
593 one that needed to be tested.
|
|
meillo@85
|
594 This situation is basically similar for the conditional TLS and SASL
|
|
meillo@85
|
595 code, but there the changes are minor and can yet be overviewed.
|
|
meillo@85
|
596 Still, conditional compilation of a code base creates variations
|
|
meillo@85
|
597 of the original program.
|
|
meillo@85
|
598 More variations require more testing and maintenance work.
|
|
meillo@85
|
599 .P
|
|
meillo@85
|
600 Two other options only specified default configuration values:
|
|
meillo@85
|
601 .Sw --with-mts=[smtp|sendmail]
|
|
meillo@85
|
602 defined the default transport service.
|
|
meillo@85
|
603 In mmh this fixed to
|
|
meillo@85
|
604 .Ar sendmail .
|
|
meillo@85
|
605 .Ci f6aa95b724fd8c791164abe7ee5468bf5c34f226
|
|
meillo@85
|
606 With
|
|
meillo@85
|
607 .Sw --with-smtpservers=[server1...]
|
|
meillo@85
|
608 default SMTP servers for the
|
|
meillo@85
|
609 .Ar smtp
|
|
meillo@85
|
610 transport service could be specified.
|
|
meillo@72
|
611 .Ci 128545e06224233b7e91fc4c83f8830252fe16c9
|
|
meillo@85
|
612 Both of them became irrelevant.
|
|
meillo@72
|
613
|
|
meillo@74
|
614 .U3 "Backup Prefix
|
|
meillo@74
|
615 .P
|
|
meillo@76
|
616 The backup prefix is the string that was prepended to message
|
|
meillo@76
|
617 filenames to tag them as deleted.
|
|
meillo@76
|
618 By default it had been the comma character `\f(CW,\fP'.
|
|
meillo@78
|
619 In July 2000, Kimmo Suominen introduced
|
|
meillo@78
|
620 the configure option
|
|
meillo@78
|
621 .Sw --with-hash-backup
|
|
meillo@78
|
622 to change the default to the hash symbol `\f(CW#\fP'.
|
|
meillo@78
|
623 The choice was probably personal preference, because first, the
|
|
meillo@78
|
624 option was named
|
|
meillo@78
|
625 .Sw --with-backup-prefix.
|
|
meillo@78
|
626 and had the prefix symbol as argument.
|
|
meillo@78
|
627 Because giving the hash symbol as argument caused to many problems
|
|
meillo@78
|
628 for configure,
|
|
meillo@78
|
629 the option was limited to use the hash symbol as the default prefix.
|
|
meillo@78
|
630 This makes me believe, that the choice for the hash was personal preference.
|
|
meillo@78
|
631 Being it related or not, words that start with the hash symbol
|
|
meillo@78
|
632 introduce a comment in the Unix shell.
|
|
meillo@72
|
633 Thus, the command line
|
|
meillo@72
|
634 .Cl "rm #13 #15
|
|
meillo@72
|
635 calls
|
|
meillo@72
|
636 .Pn rm
|
|
meillo@72
|
637 without arguments because the first hash symbol starts the comment
|
|
meillo@72
|
638 that reaches until the end of the line.
|
|
meillo@72
|
639 To delete the backup files,
|
|
meillo@72
|
640 .Cl "rm ./#13 ./#15"
|
|
meillo@72
|
641 needs to be used.
|
|
meillo@78
|
642 Using the hash as backup prefix can be seen as a precaution agains
|
|
meillo@78
|
643 data loss.
|
|
meillo@78
|
644 .P
|
|
meillo@72
|
645 I removed the configure option but added the profile entry
|
|
meillo@72
|
646 .Pe backup-prefix ,
|
|
meillo@72
|
647 which allows to specify an arbitrary string as backup prefix.
|
|
meillo@72
|
648 .Ci 6c40d481d661d532dd527eaf34cebb6d3f8ed086
|
|
meillo@76
|
649 Profile entries are the common method to change mmh's behavior.
|
|
meillo@76
|
650 This change did not remove the choice but moved it to a location where
|
|
meillo@72
|
651 it suited better.
|
|
meillo@76
|
652 .P
|
|
meillo@78
|
653 Eventually, however, the new trash folder concept
|
|
meillo@78
|
654 .Cf "Sec. XXX
|
|
meillo@78
|
655 obsoleted the concept of the backup prefix completely.
|
|
meillo@78
|
656 .Ci 8edc5aaf86f9f77124664f6801bc6c6cdf258173
|
|
meillo@72
|
657 (Well, there still are corner-cases to remove until the backup
|
|
meillo@89
|
658 prefix can be laid to rest, eventually.)
|
|
meillo@72
|
659 .\" FIXME: Do this work in the code!
|
|
meillo@76
|
660
|
|
meillo@76
|
661 .U3 "Editor and Pager
|
|
meillo@74
|
662 .P
|
|
meillo@74
|
663 The two configure options
|
|
meillo@74
|
664 .CW --with-editor=EDITOR
|
|
meillo@74
|
665 .CW --with-pager=PAGER
|
|
meillo@74
|
666 were used to specify the default editor and pager at configure time.
|
|
meillo@74
|
667 Doing so at configure time made sense in the Eighties,
|
|
meillo@76
|
668 when the set of available editors and pagers varied much across
|
|
meillo@76
|
669 different systems.
|
|
meillo@89
|
670 Today, the situation is more homogeneous.
|
|
meillo@74
|
671 The programs
|
|
meillo@74
|
672 .Pn vi
|
|
meillo@74
|
673 and
|
|
meillo@74
|
674 .Pn more
|
|
meillo@76
|
675 can be expected to be available on every Unix system,
|
|
meillo@74
|
676 as they are specified by POSIX since two decades.
|
|
meillo@74
|
677 (The specifications for
|
|
meillo@74
|
678 .Pn vi
|
|
meillo@74
|
679 and
|
|
meillo@74
|
680 .Pn more
|
|
meillo@74
|
681 appeared in
|
|
meillo@74
|
682 .[
|
|
meillo@74
|
683 posix 1987
|
|
meillo@74
|
684 .]
|
|
meillo@74
|
685 and,
|
|
meillo@74
|
686 .[
|
|
meillo@74
|
687 posix 1992
|
|
meillo@74
|
688 .]
|
|
meillo@74
|
689 respectively.)
|
|
meillo@74
|
690 As a first step, these two tools were hard-coded as defaults.
|
|
meillo@74
|
691 .Ci 5d43a99db70c12a673028c7758c20cbe3e13ef5f
|
|
meillo@74
|
692 Not changed were the
|
|
meillo@74
|
693 .Pe editor
|
|
meillo@74
|
694 and
|
|
meillo@74
|
695 .Pe moreproc
|
|
meillo@76
|
696 profile entries, which allowed the user to override the system defaults.
|
|
meillo@74
|
697 Later, the concept was reworked to respect the standard environment
|
|
meillo@74
|
698 variables
|
|
meillo@74
|
699 .Ev VISUAL
|
|
meillo@74
|
700 and
|
|
meillo@74
|
701 .Ev PAGER
|
|
meillo@76
|
702 if they are set.
|
|
meillo@74
|
703 Today, mmh determines the editor to use in the following order,
|
|
meillo@74
|
704 taking the first available and non-empty item:
|
|
meillo@74
|
705 .IP (1)
|
|
meillo@74
|
706 Environment variable
|
|
meillo@74
|
707 .Ev MMHEDITOR
|
|
meillo@74
|
708 .IP (2)
|
|
meillo@74
|
709 Profile entry
|
|
meillo@74
|
710 .Pe Editor
|
|
meillo@74
|
711 .IP (3)
|
|
meillo@74
|
712 Environment variable
|
|
meillo@74
|
713 .Ev VISUAL
|
|
meillo@74
|
714 .IP (4)
|
|
meillo@74
|
715 Environment variable
|
|
meillo@74
|
716 .Ev EDITOR
|
|
meillo@74
|
717 .IP (5)
|
|
meillo@74
|
718 Command
|
|
meillo@74
|
719 .Pn vi .
|
|
meillo@74
|
720 .P
|
|
meillo@76
|
721 .Ci f85f4b7ae62e3d05a945dcd46ead51f0a2a89a9b
|
|
meillo@76
|
722 .P
|
|
meillo@89
|
723 The pager to use is determined in a similar order,
|
|
meillo@74
|
724 also taking the first available and non-empty item:
|
|
meillo@74
|
725 .IP (1)
|
|
meillo@74
|
726 Environment variable
|
|
meillo@74
|
727 .Ev MMHPAGER
|
|
meillo@74
|
728 .IP (2)
|
|
meillo@74
|
729 Profile entry
|
|
meillo@74
|
730 .Pe Pager
|
|
meillo@74
|
731 (replaces
|
|
meillo@74
|
732 .Pe moreproc )
|
|
meillo@74
|
733 .IP (3)
|
|
meillo@74
|
734 Environment variable
|
|
meillo@74
|
735 .Ev PAGER
|
|
meillo@74
|
736 .IP (4)
|
|
meillo@74
|
737 Command
|
|
meillo@74
|
738 .Pn more .
|
|
meillo@74
|
739 .P
|
|
meillo@74
|
740 .Ci 0c4214ea2aec6497d0d67b436bbee9bc1d225f1e
|
|
meillo@74
|
741 .P
|
|
meillo@76
|
742 By respecting the
|
|
meillo@74
|
743 .Ev VISUAL /\c
|
|
meillo@74
|
744 .Ev EDITOR
|
|
meillo@74
|
745 and
|
|
meillo@74
|
746 .Ev PAGER
|
|
meillo@76
|
747 environment variables,
|
|
meillo@76
|
748 the new behavior confirms better to the common style on Unix systems.
|
|
meillo@76
|
749 Additionally, the new approach is more uniform and clearer to users.
|
|
meillo@72
|
750
|
|
meillo@74
|
751 .U3 "Locale
|
|
meillo@74
|
752 .P
|
|
meillo@74
|
753 The configure option
|
|
meillo@74
|
754 .Sw --disable-locale
|
|
meillo@85
|
755 was removed because POSIX provides locale support and there's
|
|
meillo@85
|
756 hardly any need to disable locale support.
|
|
meillo@74
|
757 .Ci ccf4f175ef4c4e7522f9510a4a1149c15d810dd9
|
|
meillo@72
|
758
|
|
meillo@76
|
759 .U3 "ndbm
|
|
meillo@72
|
760 .P
|
|
meillo@74
|
761 .Pn slocal
|
|
meillo@78
|
762 used to depend on
|
|
meillo@74
|
763 .I ndbm ,
|
|
meillo@74
|
764 a database library.
|
|
meillo@76
|
765 The database is used to store the `\fLMessage-ID\fP's of all
|
|
meillo@76
|
766 messages delivered.
|
|
meillo@74
|
767 This enables
|
|
meillo@74
|
768 .Pn slocal
|
|
meillo@74
|
769 to suppress delivering the same message to the same user twice.
|
|
meillo@74
|
770 (This features was enabled by the
|
|
meillo@74
|
771 .Sw -suppressdup
|
|
meillo@74
|
772 switch.)
|
|
meillo@74
|
773 .P
|
|
meillo@74
|
774 A variety of version of the database library exist.
|
|
meillo@78
|
775 .[
|
|
meillo@78
|
776 wolter unix incompat notes dbm
|
|
meillo@78
|
777 .]
|
|
meillo@74
|
778 Complicated autoconf code was needed to detect them correctly.
|
|
meillo@74
|
779 Further more, the configure switches
|
|
meillo@74
|
780 .Sw --with-ndbm=ARG
|
|
meillo@74
|
781 and
|
|
meillo@74
|
782 .Sw --with-ndbmheader=ARG
|
|
meillo@74
|
783 were added to help with difficult setups that would
|
|
meillo@78
|
784 not be detected automatically or correctly.
|
|
meillo@74
|
785 .P
|
|
meillo@74
|
786 By removing the suppress duplicates feature of
|
|
meillo@74
|
787 .Pn slocal ,
|
|
meillo@74
|
788 the dependency on
|
|
meillo@74
|
789 .I ndbm
|
|
meillo@78
|
790 vanished and 120 lines of complex autoconf code could be saved.
|
|
meillo@74
|
791 .Ci ecd6d6a20cb7a1507e3a20d6c4cb3a1cf14c6bbf
|
|
meillo@89
|
792 The change removed functionality too, but that is minor to the
|
|
meillo@78
|
793 improvement by dropping the dependency and the complex autoconf code.
|
|
meillo@72
|
794
|
|
meillo@74
|
795 .U3 "mh-e Support
|
|
meillo@72
|
796 .P
|
|
meillo@74
|
797 The configure option
|
|
meillo@74
|
798 .Sw --disable-mhe
|
|
meillo@74
|
799 was removed when the mh-e support was reworked.
|
|
meillo@74
|
800 Mh-e is the Emacs front-end to MH.
|
|
meillo@76
|
801 It requires MH to provide minor additional functions.
|
|
meillo@76
|
802 The
|
|
meillo@76
|
803 .Sw --disable-mhe
|
|
meillo@76
|
804 configure option could switch these extensions off.
|
|
meillo@76
|
805 After removing the support for old versions of mh-e,
|
|
meillo@74
|
806 only the
|
|
meillo@74
|
807 .Sw -build
|
|
meillo@76
|
808 switches of
|
|
meillo@74
|
809 .Pn forw
|
|
meillo@74
|
810 and
|
|
meillo@74
|
811 .Pn repl
|
|
meillo@76
|
812 are left to be mh-e extensions.
|
|
meillo@76
|
813 They are now always built in because they add little code and complexity.
|
|
meillo@76
|
814 In consequence, the
|
|
meillo@74
|
815 .Sw --disable-mhe
|
|
meillo@76
|
816 configure option was removed
|
|
meillo@72
|
817 .Ci a7ce7b4a580d77b6c2c4d980812beb589aa4c643
|
|
meillo@74
|
818 Removing the option removed a second code setup that would have
|
|
meillo@74
|
819 needed to be tested.
|
|
meillo@76
|
820 This change was first done in nmh and thereafter merged into mmh.
|
|
meillo@76
|
821 .P
|
|
meillo@76
|
822 The interface changes in mmh require mh-e to be adjusted in order
|
|
meillo@76
|
823 to be able to use mmh as back-end.
|
|
meillo@76
|
824 This will require minor changes to mh-e, but removing the
|
|
meillo@76
|
825 .Sw -build
|
|
meillo@76
|
826 switches would require more rework.
|
|
meillo@72
|
827
|
|
meillo@74
|
828 .U3 "Masquerading
|
|
meillo@72
|
829 .P
|
|
meillo@74
|
830 The configure option
|
|
meillo@74
|
831 .Sw --enable-masquerade
|
|
meillo@76
|
832 could take up to three arguments:
|
|
meillo@76
|
833 `draft_from', `mmailid', and `username_extension'.
|
|
meillo@74
|
834 They activated different types of address masquerading.
|
|
meillo@74
|
835 All of them were implemented in the SMTP-speaking
|
|
meillo@74
|
836 .Pn post
|
|
meillo@76
|
837 command, which provided an MSA.
|
|
meillo@76
|
838 Address masquerading is an MTA's task and mmh does not cover
|
|
meillo@76
|
839 this field anymore.
|
|
meillo@76
|
840 Hence, true masquerading needs to be implemented in the external MTA.
|
|
meillo@74
|
841 .P
|
|
meillo@74
|
842 The
|
|
meillo@74
|
843 .I mmailid
|
|
meillo@74
|
844 masquerading type is the oldest one of the three and the only one
|
|
meillo@74
|
845 available in the original MH.
|
|
meillo@74
|
846 It provided a
|
|
meillo@74
|
847 .I username
|
|
meillo@74
|
848 to
|
|
meillo@74
|
849 .I fakeusername
|
|
meillo@76
|
850 mapping, based on the password file's GECOS field.
|
|
meillo@74
|
851 The man page
|
|
meillo@74
|
852 .Mp mh-tailor(5)
|
|
meillo@74
|
853 described the use case as being the following:
|
|
meillo@74
|
854 .QP
|
|
meillo@74
|
855 This is useful if you want the messages you send to always
|
|
meillo@74
|
856 appear to come from the name of an MTA alias rather than your
|
|
meillo@74
|
857 actual account name. For instance, many organizations set up
|
|
meillo@74
|
858 `First.Last' sendmail aliases for all users. If this is
|
|
meillo@74
|
859 the case, the GECOS field for each user should look like:
|
|
meillo@74
|
860 ``First [Middle] Last <First.Last>''
|
|
meillo@74
|
861 .P
|
|
meillo@74
|
862 As mmh sends outgoing mail via the local MTA only,
|
|
meillo@76
|
863 the best location to do such global rewrites is there.
|
|
meillo@74
|
864 Besides, the MTA is conceptionally the right location because it
|
|
meillo@74
|
865 does the reverse mapping for incoming mail (aliasing), too.
|
|
meillo@76
|
866 Further more, masquerading set up there is readily available for all
|
|
meillo@74
|
867 mail software on the system.
|
|
meillo@76
|
868 Hence, mmailid masquerading was removed.
|
|
meillo@74
|
869 .Ci 0836c8000ccb34b59410ef1c15b1b7feac70ce5f
|
|
meillo@74
|
870 .P
|
|
meillo@74
|
871 The
|
|
meillo@74
|
872 .I username_extension
|
|
meillo@76
|
873 masquerading type did not replace the username but would append a suffix,
|
|
meillo@76
|
874 specified by the
|
|
meillo@74
|
875 .Ev USERNAME_EXTENSION
|
|
meillo@76
|
876 environment variable, to it.
|
|
meillo@76
|
877 This provided support for the
|
|
meillo@74
|
878 .I user-extension
|
|
meillo@74
|
879 feature of qmail and the similar
|
|
meillo@74
|
880 .I "plussed user
|
|
meillo@74
|
881 processing of sendmail.
|
|
meillo@74
|
882 The decision to remove this username_extension masquerading was
|
|
meillo@74
|
883 motivated by the fact that
|
|
meillo@74
|
884 .Pn spost
|
|
meillo@76
|
885 hadn't supported it already.
|
|
meillo@76
|
886 .Ci 2abae0bfd0ad5bf898461e50aa4b466d641f23d9
|
|
meillo@76
|
887 Username extensions are possible in mmh, but less convenient to use.
|
|
meillo@76
|
888 .\" XXX format file %(getenv USERNAME_EXTENSION)
|
|
meillo@74
|
889 .P
|
|
meillo@74
|
890 The
|
|
meillo@74
|
891 .I draft_from
|
|
meillo@74
|
892 masquerading type instructed
|
|
meillo@74
|
893 .Pn post
|
|
meillo@84
|
894 to use the value of the
|
|
meillo@84
|
895 .Hd From
|
|
meillo@84
|
896 header field as SMTP envelope sender.
|
|
meillo@76
|
897 Sender addresses could be replaced completely.
|
|
meillo@74
|
898 .Ci b14ea6073f77b4359aaf3fddd0e105989db9
|
|
meillo@76
|
899 Mmh offers a kind of masquerading similar in effect, but
|
|
meillo@74
|
900 with technical differences.
|
|
meillo@76
|
901 As mmh does not transfer messages itself, the local MTA has final control
|
|
meillo@76
|
902 over the sender's address. Any masquerading mmh introduces may be reverted
|
|
meillo@76
|
903 by the MTA.
|
|
meillo@76
|
904 In times of pedantic spam checking, an MTA will take care to use
|
|
meillo@76
|
905 sensible envelope sender addresses to keep its own reputation up.
|
|
meillo@84
|
906 Nonetheless, the MUA can set the
|
|
meillo@84
|
907 .Hd From
|
|
meillo@84
|
908 header field and thereby propose
|
|
meillo@76
|
909 a sender address to the MTA.
|
|
meillo@74
|
910 The MTA may then decide to take that one or generate the canonical sender
|
|
meillo@74
|
911 address for use as envelope sender address.
|
|
meillo@74
|
912 .P
|
|
meillo@74
|
913 In mmh, the MTA will always extract the recipient and sender from the
|
|
meillo@84
|
914 message header (\c
|
|
meillo@74
|
915 .Pn sendmail 's
|
|
meillo@74
|
916 .Sw -t
|
|
meillo@74
|
917 switch).
|
|
meillo@84
|
918 The
|
|
meillo@84
|
919 .Hd From
|
|
meillo@84
|
920 header field of the draft may be set arbitrary by the user.
|
|
meillo@74
|
921 If it is missing, the canonical sender address will be generated by the MTA.
|
|
meillo@74
|
922
|
|
meillo@74
|
923 .U3 "Remaining Options
|
|
meillo@74
|
924 .P
|
|
meillo@74
|
925 Two configure options remain in mmh.
|
|
meillo@74
|
926 One is the locking method to use:
|
|
meillo@74
|
927 .Sw --with-locking=[dot|fcntl|flock|lockf] .
|
|
meillo@76
|
928 The idea of removing all methods except the portable dot locking
|
|
meillo@76
|
929 and having that one as the default is appealing, but this change
|
|
meillo@76
|
930 requires deeper technical investigation into the topic.
|
|
meillo@76
|
931 The other option,
|
|
meillo@74
|
932 .Sw --enable-debug ,
|
|
meillo@74
|
933 compiles the programs with debugging symbols and does not strip them.
|
|
meillo@74
|
934 This option is likely to stay.
|
|
meillo@72
|
935
|
|
meillo@72
|
936
|
|
meillo@58
|
937
|
|
meillo@63
|
938
|
|
meillo@93
|
939 .H2 "Removal of Switches
|
|
meillo@58
|
940 .P
|
|
meillo@93
|
941 The command line switches of MH tools follow the X Window style.
|
|
meillo@93
|
942 They are words, introduced by a single dash.
|
|
meillo@93
|
943 For example:
|
|
meillo@93
|
944 .Cl "-truncate" .
|
|
meillo@93
|
945 Every program in mmh has two generic switches:
|
|
meillo@93
|
946 .Sw -help ,
|
|
meillo@93
|
947 to print a short message on how to use the program, and
|
|
meillo@93
|
948 .Sw -Version ,
|
|
meillo@93
|
949 to tell what version of mmh the program belongs to.
|
|
meillo@93
|
950 .P
|
|
meillo@93
|
951 Switches change the behavior of programs.
|
|
meillo@93
|
952 Programs that do one thing in one way require no switches.
|
|
meillo@93
|
953 In most cases, doing something in exactly one way is too limiting.
|
|
meillo@93
|
954 If it is basically the same task to accomplish, but it should be done
|
|
meillo@93
|
955 in various ways, switches are a good approach to alter the behavior
|
|
meillo@93
|
956 of a program.
|
|
meillo@93
|
957 Changing the behavior of programs provides flexibility and customization
|
|
meillo@93
|
958 to users, but in the same way it complicates the code, documentation and
|
|
meillo@93
|
959 usage of the program.
|
|
meillo@93
|
960 Therefore, the number of switches should be kept small.
|
|
meillo@93
|
961 A small set of well-chosen switches does no harm.
|
|
meillo@93
|
962 But usually, the number of switches increases over time.
|
|
meillo@93
|
963 Already in 1985, Rose and Romine have identified this as a major
|
|
meillo@93
|
964 problem of MH:
|
|
meillo@93
|
965 .[ [
|
|
meillo@93
|
966 rose romine real work
|
|
meillo@93
|
967 .], p. 12]
|
|
meillo@93
|
968 .sp
|
|
meillo@93
|
969 .QP
|
|
meillo@93
|
970 A complaint often heard about systems which undergo substantial development
|
|
meillo@93
|
971 by many people over a number of years, is that more and more options are
|
|
meillo@93
|
972 introduced which add little to the functionality but greatly increase the
|
|
meillo@93
|
973 amount of information a user needs to know in order to get useful work done.
|
|
meillo@93
|
974 This is usually referred to as creeping featurism.
|
|
meillo@93
|
975 .QP
|
|
meillo@93
|
976 Unfortunately MH, having undergone six years of off-and-on development by
|
|
meillo@93
|
977 ten or so well-meaning programmers (the present authors included),
|
|
meillo@93
|
978 suffers mightily from this.
|
|
meillo@93
|
979 .sp
|
|
meillo@93
|
980 .P
|
|
meillo@93
|
981 Adding new switches only reluctantly is one part of the counter-action,
|
|
meillo@93
|
982 the other is removing hardly used switches.
|
|
meillo@93
|
983 Now that there are lots of switches already implemented,
|
|
meillo@93
|
984 removing some of them is more important.
|
|
meillo@93
|
985 Removing existing functionality is always difficult because it
|
|
meillo@93
|
986 breaks programs that use these functions.
|
|
meillo@93
|
987 Also, for every obsolete feature, there'll always be someone who still
|
|
meillo@93
|
988 uses it and thus opposes its removal.
|
|
meillo@93
|
989 This puts the developer into the position,
|
|
meillo@93
|
990 where sensible improvements to style are regarded as destructive acts.
|
|
meillo@93
|
991 Yet, living with the featurism is far worse, in my eyes.
|
|
meillo@93
|
992 Future needs will demand adding new features,
|
|
meillo@93
|
993 worsening the situation more and more.
|
|
meillo@93
|
994 Rose and Romine added in a footnote,
|
|
meillo@93
|
995 ``[...]
|
|
meillo@93
|
996 .Pn send
|
|
meillo@93
|
997 will no doubt acquire an endless number of switches in the years to come.''
|
|
meillo@93
|
998 Although clearly humorous, the comment displays the nature of
|
|
meillo@93
|
999 the problem.
|
|
meillo@93
|
1000 Though refusing to add any new switches would encounter the problem
|
|
meillo@93
|
1001 at its root, it is not practical.
|
|
meillo@93
|
1002 But removing obsolete switches is an effective approach to deal with the
|
|
meillo@93
|
1003 problem.
|
|
meillo@93
|
1004 Working on an experimental branch,
|
|
meillo@93
|
1005 eased this work because I had not to offend users.
|
|
meillo@93
|
1006 .P
|
|
meillo@93
|
1007 Rose and Romine counted 24 visible and 9 more hidden switches for
|
|
meillo@93
|
1008 .Pn send .
|
|
meillo@93
|
1009 At the beginning of mmh, it were 32 visible and 12 hidden ones.
|
|
meillo@93
|
1010 At the time of writing, mmh's
|
|
meillo@93
|
1011 .Pn send
|
|
meillo@93
|
1012 has 7 visible switches and 1 hidden switch.
|
|
meillo@93
|
1013 (In each of the examples, the two generic help and version switches
|
|
meillo@93
|
1014 are included.)
|
|
meillo@93
|
1015 .P
|
|
meillo@93
|
1016 Figure XXX
|
|
meillo@93
|
1017 .\" XXX Ref
|
|
meillo@93
|
1018 displays the number of switches for each of the tools that was not
|
|
meillo@93
|
1019 removed from or newly added to mmh.
|
|
meillo@93
|
1020 Both, visible and hidden switches, were counted, but
|
|
meillo@93
|
1021 not the generic help and version switches.
|
|
meillo@93
|
1022 Whereas in the beginning of the project, the average tool had 11 switches,
|
|
meillo@93
|
1023 now it has no more than 5 \(en only half as many.
|
|
meillo@93
|
1024 If the `no' switches and similar inverse variant are folded onto
|
|
meillo@93
|
1025 their counter-parts, the numbers are 8 in pre-mmh to 4 now.
|
|
meillo@93
|
1026 The total number of functional switches in mmh dropped from 465
|
|
meillo@93
|
1027 to 234.
|
|
meillo@58
|
1028
|
|
meillo@93
|
1029 .KS
|
|
meillo@93
|
1030 .in 1c
|
|
meillo@93
|
1031 .so input/switches.grap
|
|
meillo@93
|
1032 .KE
|
|
meillo@58
|
1033
|
|
meillo@93
|
1034 .P
|
|
meillo@93
|
1035 A part of the switches vanished after functions were removed.
|
|
meillo@93
|
1036 This was the case for network mail transfer, for instance.
|
|
meillo@93
|
1037 Sometimes the work flow was the other way:
|
|
meillo@93
|
1038 The trying to reduce the number of switches suggested the removal of
|
|
meillo@93
|
1039 functions.
|
|
meillo@58
|
1040
|
|
meillo@93
|
1041 .U3 "Draft Folder Facility
|
|
meillo@93
|
1042 .P
|
|
meillo@93
|
1043 A change early in the project was the completely transition from
|
|
meillo@93
|
1044 the single draft message to the draft folder facility.
|
|
meillo@93
|
1045 The draft folder facility was introduced in the mid-Eighties.
|
|
meillo@93
|
1046 (Rose and Romine called it a ``relatively new feature''
|
|
meillo@93
|
1047 .[
|
|
meillo@93
|
1048 rose romine real work
|
|
meillo@93
|
1049 .]
|
|
meillo@93
|
1050 in 1985.)
|
|
meillo@96
|
1051 Since then, the facility had existed but had remained deactivated
|
|
meillo@96
|
1052 by default.
|
|
meillo@93
|
1053 The default activation and the related rework of the tools made it
|
|
meillo@93
|
1054 possible to remove the
|
|
meillo@93
|
1055 .Sw -[no]draftfolder ,
|
|
meillo@93
|
1056 and
|
|
meillo@93
|
1057 .Sw -draftmessage
|
|
meillo@93
|
1058 switches from
|
|
meillo@93
|
1059 .Pn comp ,
|
|
meillo@93
|
1060 .Pn repl ,
|
|
meillo@93
|
1061 .Pn forw ,
|
|
meillo@93
|
1062 .Pn dist ,
|
|
meillo@93
|
1063 .Pn whatnow ,
|
|
meillo@93
|
1064 and
|
|
meillo@93
|
1065 .Pn send .
|
|
meillo@93
|
1066 The only flexibility removed is having multiple draft folders
|
|
meillo@93
|
1067 within one profile.
|
|
meillo@93
|
1068 I consider this only a theoretical setup.
|
|
meillo@93
|
1069 In the same go, the
|
|
meillo@93
|
1070 .Sw -draft
|
|
meillo@93
|
1071 switch of
|
|
meillo@93
|
1072 .Pn anno ,
|
|
meillo@93
|
1073 .Pn refile ,
|
|
meillo@93
|
1074 and
|
|
meillo@93
|
1075 .Pn send
|
|
meillo@93
|
1076 was removed.
|
|
meillo@93
|
1077 The special-casing of `the' draft message became irrelevant after
|
|
meillo@93
|
1078 the rework of the draft system.
|
|
meillo@93
|
1079 (See Sec. XXX.)
|
|
meillo@95
|
1080 Equally,
|
|
meillo@95
|
1081 .Pn comp
|
|
meillo@95
|
1082 lost its
|
|
meillo@95
|
1083 .Sw -file
|
|
meillo@95
|
1084 switch.
|
|
meillo@95
|
1085 The draft folder facility, together with the
|
|
meillo@95
|
1086 .Sw -form
|
|
meillo@95
|
1087 switch, are sufficient.
|
|
meillo@93
|
1088
|
|
meillo@95
|
1089
|
|
meillo@95
|
1090 .U3 "Inplace Editing
|
|
meillo@93
|
1091 .P
|
|
meillo@93
|
1092 .Pn anno
|
|
meillo@93
|
1093 had the switches
|
|
meillo@93
|
1094 .Sw -[no]inplace
|
|
meillo@93
|
1095 to either annotate the message inplace and thus preserve hard links,
|
|
meillo@93
|
1096 or annotate a copy to replace the original message, breaking hard links.
|
|
meillo@93
|
1097 Following the assumption that linked messages are the same message,
|
|
meillo@93
|
1098 and annotating it should not break the link, the
|
|
meillo@93
|
1099 .Sw -[no]inplace
|
|
meillo@93
|
1100 switches were removed and the previous default
|
|
meillo@93
|
1101 .Sw -inplace
|
|
meillo@93
|
1102 was made the only behavior.
|
|
meillo@93
|
1103 The
|
|
meillo@93
|
1104 .Sw -[no]inplace
|
|
meillo@93
|
1105 switches of
|
|
meillo@93
|
1106 .Pn repl ,
|
|
meillo@93
|
1107 .Pn forw ,
|
|
meillo@93
|
1108 and
|
|
meillo@93
|
1109 .Pn dist
|
|
meillo@93
|
1110 could be removed, too, as they were simply passed through to
|
|
meillo@93
|
1111 .Pn anno .
|
|
meillo@93
|
1112 .P
|
|
meillo@93
|
1113 .Pn burst
|
|
meillo@93
|
1114 also had
|
|
meillo@93
|
1115 .Sw -[no]inplace
|
|
meillo@95
|
1116 switches, but with different meaning.
|
|
meillo@95
|
1117 With
|
|
meillo@95
|
1118 .Sw -inplace ,
|
|
meillo@95
|
1119 the digest had been replaced by the table of contents (i.e. the
|
|
meillo@95
|
1120 introduction text) and the bursted messages were placed right
|
|
meillo@95
|
1121 after this message, renumbering all following messages.
|
|
meillo@95
|
1122 Also, any trailing text of the digest was lost, though,
|
|
meillo@95
|
1123 in practice, it usually consists of an end-of-digest marker only.
|
|
meillo@95
|
1124 Nontheless, this behavior appeared less elegant than the
|
|
meillo@95
|
1125 .Sw -noinplace
|
|
meillo@95
|
1126 behavior, which already had been the default.
|
|
meillo@95
|
1127 Nmh's
|
|
meillo@95
|
1128 .Mp burst (1)
|
|
meillo@95
|
1129 man page reads:
|
|
meillo@95
|
1130 .sp \n(PDu
|
|
meillo@93
|
1131 .QP
|
|
meillo@93
|
1132 If -noinplace is given, each digest is preserved, no table
|
|
meillo@93
|
1133 of contents is produced, and the messages contained within
|
|
meillo@93
|
1134 the digest are placed at the end of the folder. Other messages
|
|
meillo@93
|
1135 are not tampered with in any way.
|
|
meillo@95
|
1136 .sp \n(PDu
|
|
meillo@95
|
1137 .LP
|
|
meillo@93
|
1138 The decision to drop the
|
|
meillo@93
|
1139 .Sw -inplace
|
|
meillo@95
|
1140 behavior was supported by the code complexity and the possible data loss
|
|
meillo@95
|
1141 it caused.
|
|
meillo@93
|
1142 .Sw -noinplace
|
|
meillo@95
|
1143 was chosen to be the definitive behavior.
|
|
meillo@93
|
1144
|
|
meillo@95
|
1145
|
|
meillo@95
|
1146 .U3 "Forms and Format Strings
|
|
meillo@93
|
1147 .P
|
|
meillo@95
|
1148 Historically, the tools that had
|
|
meillo@95
|
1149 .Sw -form
|
|
meillo@95
|
1150 switches to supply a form file had
|
|
meillo@95
|
1151 .Sw -format
|
|
meillo@95
|
1152 switches as well to supply the contents of a form file as a string
|
|
meillo@95
|
1153 on the command line directly.
|
|
meillo@95
|
1154 In consequence, the following two lines equaled:
|
|
meillo@95
|
1155 .VS
|
|
meillo@95
|
1156 scan -form scan.mailx
|
|
meillo@95
|
1157 scan -format "`cat .../scan.mailx`"
|
|
meillo@95
|
1158 VE
|
|
meillo@95
|
1159 The
|
|
meillo@95
|
1160 .Sw -format
|
|
meillo@95
|
1161 switches were dropped in favor for extending the
|
|
meillo@95
|
1162 .Sw -form
|
|
meillo@95
|
1163 switches.
|
|
meillo@95
|
1164 If their argument starts with an equal sign (`='),
|
|
meillo@95
|
1165 then the rest of the argument is taken as a format string,
|
|
meillo@95
|
1166 otherwise the arguments is treated as the name of a format file.
|
|
meillo@95
|
1167 Thus, now the following two lines equal:
|
|
meillo@95
|
1168 .VS
|
|
meillo@95
|
1169 scan -form scan.mailx
|
|
meillo@95
|
1170 scan -form "=`cat .../scan.mailx`"
|
|
meillo@95
|
1171 VE
|
|
meillo@95
|
1172 This rework removed the prefix collision between
|
|
meillo@95
|
1173 .Sw -form
|
|
meillo@95
|
1174 and
|
|
meillo@95
|
1175 .Sw -format .
|
|
meillo@95
|
1176 Now, typing
|
|
meillo@95
|
1177 .Sw -fo
|
|
meillo@95
|
1178 suffices to specify form or format string.
|
|
meillo@95
|
1179 .P
|
|
meillo@95
|
1180 The different meaning of
|
|
meillo@95
|
1181 .Sw -format
|
|
meillo@95
|
1182 for
|
|
meillo@95
|
1183 .Pn repl
|
|
meillo@95
|
1184 and
|
|
meillo@95
|
1185 .Pn forw
|
|
meillo@95
|
1186 was removed in mmh.
|
|
meillo@95
|
1187 .Pn forw
|
|
meillo@95
|
1188 was completely switched to MIME-type forwarding, thus removing the
|
|
meillo@95
|
1189 .Sw -[no]format .
|
|
meillo@95
|
1190 For
|
|
meillo@95
|
1191 .Pn repl ,
|
|
meillo@95
|
1192 the
|
|
meillo@95
|
1193 .Sw -[no]format
|
|
meillo@95
|
1194 switches were reworked to
|
|
meillo@95
|
1195 .Sw -[no]filter
|
|
meillo@95
|
1196 switches.
|
|
meillo@95
|
1197 The
|
|
meillo@95
|
1198 .Sw -format
|
|
meillo@95
|
1199 switches of
|
|
meillo@95
|
1200 .Pn send
|
|
meillo@95
|
1201 and
|
|
meillo@95
|
1202 .Pn post ,
|
|
meillo@95
|
1203 which had a third meaning,
|
|
meillo@95
|
1204 were removed likewise.
|
|
meillo@95
|
1205 Eventually, the ambiguity of the
|
|
meillo@95
|
1206 .Sw -format
|
|
meillo@95
|
1207 switches was resolved by not anymore having any such switch in mmh.
|
|
meillo@95
|
1208
|
|
meillo@95
|
1209
|
|
meillo@95
|
1210 .U3 "MIME Tools
|
|
meillo@95
|
1211 .P
|
|
meillo@95
|
1212 The MIME tools, which were once part of
|
|
meillo@95
|
1213 .Pn mhn ,
|
|
meillo@95
|
1214 had several switches that added little practical value to the programs.
|
|
meillo@95
|
1215 The
|
|
meillo@95
|
1216 .Sw -[no]realsize
|
|
meillo@95
|
1217 switches of
|
|
meillo@95
|
1218 .Pn mhbuild
|
|
meillo@95
|
1219 and
|
|
meillo@95
|
1220 .Pn mhlist
|
|
meillo@95
|
1221 were removed, doing real size calculations always now, as
|
|
meillo@95
|
1222 ``This provides an accurate count at the expense of a small delay.''
|
|
meillo@95
|
1223 This small delay is not noticable on modern systems.
|
|
meillo@95
|
1224 .P
|
|
meillo@95
|
1225 The
|
|
meillo@95
|
1226 .Sw -[no]check
|
|
meillo@95
|
1227 switches were removed together with the support for
|
|
meillo@95
|
1228 .Hd Content-MD5
|
|
meillo@95
|
1229 header fields.
|
|
meillo@95
|
1230 .[
|
|
meillo@95
|
1231 rfc 1864
|
|
meillo@95
|
1232 .]
|
|
meillo@95
|
1233 (See Sec. XXX)
|
|
meillo@95
|
1234 .P
|
|
meillo@95
|
1235 The
|
|
meillo@95
|
1236 .Sw -[no]ebcdicsafe
|
|
meillo@95
|
1237 and
|
|
meillo@95
|
1238 .Sw -[no]rfc934mode
|
|
meillo@95
|
1239 switches of
|
|
meillo@95
|
1240 .Pn mhbuild
|
|
meillo@95
|
1241 were removed because they are considered obsolete.
|
|
meillo@95
|
1242 .P
|
|
meillo@95
|
1243 Content caching of external MIME parts, activated with the
|
|
meillo@95
|
1244 .Sw -rcache
|
|
meillo@95
|
1245 and
|
|
meillo@95
|
1246 .Sw -wcache
|
|
meillo@95
|
1247 switches was completely removed.
|
|
meillo@95
|
1248 External MIME parts are truly rare today, having a caching facility
|
|
meillo@96
|
1249 for them is appears to be unnecessary.
|
|
meillo@95
|
1250 .P
|
|
meillo@95
|
1251 In pre-MIME times,
|
|
meillo@95
|
1252 .Pn mhl
|
|
meillo@95
|
1253 had covered many tasks that are part of MIME handling today.
|
|
meillo@95
|
1254 Therefore,
|
|
meillo@95
|
1255 .Pn mhl
|
|
meillo@95
|
1256 could be simplified to a large extend, reducing the number of its
|
|
meillo@95
|
1257 switches from 21 to 6.
|
|
meillo@95
|
1258
|
|
meillo@95
|
1259
|
|
meillo@95
|
1260 .U3 "Mail Transfer Switches
|
|
meillo@95
|
1261 .P
|
|
meillo@95
|
1262 With the removal of the mail transfer facilities, a lot of switches
|
|
meillo@95
|
1263 vanished automatically.
|
|
meillo@95
|
1264 .Pn inc
|
|
meillo@95
|
1265 lost 9 switches, namely
|
|
meillo@95
|
1266 .Sw -host ,
|
|
meillo@95
|
1267 .Sw -port ,
|
|
meillo@95
|
1268 .Sw -user ,
|
|
meillo@95
|
1269 .Sw -proxy ,
|
|
meillo@95
|
1270 .Sw -snoop ,
|
|
meillo@95
|
1271 .Sw -[no]pack ,
|
|
meillo@95
|
1272 as well as
|
|
meillo@95
|
1273 .Sw -sasl
|
|
meillo@95
|
1274 and
|
|
meillo@95
|
1275 .Sw -saslmech .
|
|
meillo@95
|
1276 .Pn send
|
|
meillo@95
|
1277 and
|
|
meillo@95
|
1278 .Pn post
|
|
meillo@95
|
1279 lost 11 switches each, namely
|
|
meillo@95
|
1280 .Sw -server ,
|
|
meillo@95
|
1281 .Sw -port ,
|
|
meillo@95
|
1282 .Sw -client ,
|
|
meillo@95
|
1283 .Sw -user ,
|
|
meillo@95
|
1284 .Sw -mail ,
|
|
meillo@95
|
1285 .Sw -saml ,
|
|
meillo@95
|
1286 .Sw -send ,
|
|
meillo@95
|
1287 .Sw -soml ,
|
|
meillo@95
|
1288 .Sw -snoop ,
|
|
meillo@95
|
1289 as well as
|
|
meillo@95
|
1290 .Sw -sasl ,
|
|
meillo@95
|
1291 .Sw -saslmech ,
|
|
meillo@95
|
1292 and
|
|
meillo@95
|
1293 .Sw -tls .
|
|
meillo@95
|
1294 .Pn send
|
|
meillo@95
|
1295 had the switches only to pass them further to
|
|
meillo@95
|
1296 .Pn post ,
|
|
meillo@95
|
1297 because the user would invoke
|
|
meillo@95
|
1298 .Pn post
|
|
meillo@95
|
1299 not directly, but through
|
|
meillo@95
|
1300 .Pn send .
|
|
meillo@95
|
1301 All these switches, except
|
|
meillo@95
|
1302 .Sw -snoop
|
|
meillo@95
|
1303 were usually defined as default switches in the user's profile,
|
|
meillo@95
|
1304 but hardly given in interactive usage.
|
|
meillo@95
|
1305 .P
|
|
meillo@95
|
1306 Of course, those switches did not really ``vanish'', but the configuration
|
|
meillo@95
|
1307 they did was handed over to external MSAs and MRAs.
|
|
meillo@95
|
1308 Instead of setting up the mail transfer in mmh, it is set up in
|
|
meillo@95
|
1309 external tools.
|
|
meillo@95
|
1310 Yet, this simplifies mmh.
|
|
meillo@95
|
1311 Specialized external tools will likely have simple configuration files.
|
|
meillo@95
|
1312 Hence, instead of having one complicated central configuration file,
|
|
meillo@95
|
1313 the configuration of each domain is separate.
|
|
meillo@95
|
1314 Although the user needs to learn to configure each of the tools,
|
|
meillo@95
|
1315 each configuration is likely much simpler.
|
|
meillo@95
|
1316
|
|
meillo@95
|
1317
|
|
meillo@95
|
1318 .U3 "Maildrop Formats
|
|
meillo@95
|
1319 .P
|
|
meillo@95
|
1320 With the removal of MMDF maildrop format support,
|
|
meillo@95
|
1321 .Pn packf
|
|
meillo@95
|
1322 and
|
|
meillo@95
|
1323 .Pn rcvpack
|
|
meillo@95
|
1324 no longer needed their
|
|
meillo@95
|
1325 .Sw -mbox
|
|
meillo@95
|
1326 and
|
|
meillo@95
|
1327 .Sw -mmdf
|
|
meillo@95
|
1328 switches.
|
|
meillo@95
|
1329 .Sw -mbox
|
|
meillo@95
|
1330 is the sole behavior now.
|
|
meillo@95
|
1331 In the same go,
|
|
meillo@95
|
1332 .Pn packf
|
|
meillo@95
|
1333 was reworked (see Sec. XXX) and its
|
|
meillo@95
|
1334 .Sw -file
|
|
meillo@95
|
1335 switch became unnecessary.
|
|
meillo@95
|
1336
|
|
meillo@95
|
1337
|
|
meillo@95
|
1338 .U3 "Terminal Magic
|
|
meillo@95
|
1339 .P
|
|
meillo@95
|
1340 Mmh's tools will no longer clear the screen (\c
|
|
meillo@95
|
1341 .Pn scan 's
|
|
meillo@95
|
1342 and
|
|
meillo@95
|
1343 .Pn mhl 's
|
|
meillo@95
|
1344 .Sw -[no]clear
|
|
meillo@95
|
1345 switches).
|
|
meillo@95
|
1346 Neither will
|
|
meillo@95
|
1347 .Pn mhl
|
|
meillo@95
|
1348 ring the bell (\c
|
|
meillo@95
|
1349 .Sw -[no]bell )
|
|
meillo@95
|
1350 nor page the output itself (\c
|
|
meillo@95
|
1351 .Sw -length ).
|
|
meillo@95
|
1352 .P
|
|
meillo@95
|
1353 Generally, the pager to use is no longer specified with the
|
|
meillo@95
|
1354 .Sw -[no]moreproc
|
|
meillo@95
|
1355 command line switches for
|
|
meillo@95
|
1356 .Pn mhl
|
|
meillo@95
|
1357 and
|
|
meillo@95
|
1358 .Pn show /\c
|
|
meillo@95
|
1359 .Pn mhshow .
|
|
meillo@95
|
1360 .P
|
|
meillo@95
|
1361 .Pn prompter
|
|
meillo@95
|
1362 lost its
|
|
meillo@95
|
1363 .Sw -erase
|
|
meillo@95
|
1364 and
|
|
meillo@95
|
1365 .Sw -kill
|
|
meillo@95
|
1366 switches because today the terminal cares for the line editing keys.
|
|
meillo@95
|
1367
|
|
meillo@95
|
1368
|
|
meillo@95
|
1369 .U3 "Header Printing
|
|
meillo@95
|
1370 .P
|
|
meillo@95
|
1371 .Pn folder 's
|
|
meillo@95
|
1372 data output is self-explaining enough that
|
|
meillo@95
|
1373 displaying the header line makes few sense.
|
|
meillo@95
|
1374 Hence, the
|
|
meillo@95
|
1375 .Sw -[no]header
|
|
meillo@95
|
1376 switch was removed and headers are never printed.
|
|
meillo@95
|
1377 .P
|
|
meillo@95
|
1378 In
|
|
meillo@95
|
1379 .Pn mhlist ,
|
|
meillo@95
|
1380 the
|
|
meillo@95
|
1381 .Sw -[no]header
|
|
meillo@95
|
1382 switches were removed, too.
|
|
meillo@95
|
1383 But in this case headers are always printed,
|
|
meillo@95
|
1384 because the output is not self-explaining.
|
|
meillo@95
|
1385 .P
|
|
meillo@95
|
1386 .Pn scan
|
|
meillo@95
|
1387 also had
|
|
meillo@95
|
1388 .Sw -[no]header
|
|
meillo@95
|
1389 switches.
|
|
meillo@95
|
1390 Printing the header had been sensible until the introduction of
|
|
meillo@95
|
1391 format strings made it impossible to display the column headings.
|
|
meillo@95
|
1392 Only the folder name and the current date remained to be printed.
|
|
meillo@95
|
1393 As this information can be perfectly retrieved by
|
|
meillo@95
|
1394 .Pn folder
|
|
meillo@95
|
1395 and
|
|
meillo@95
|
1396 .Pn date ,
|
|
meillo@95
|
1397 consequently, the switches were removed.
|
|
meillo@95
|
1398 .P
|
|
meillo@95
|
1399 By removing all
|
|
meillo@95
|
1400 .Sw -header
|
|
meillo@95
|
1401 switches, the collision with
|
|
meillo@95
|
1402 .Sw -help
|
|
meillo@95
|
1403 on the first two letters was resolved.
|
|
meillo@95
|
1404 Currently,
|
|
meillo@95
|
1405 .Sw -h
|
|
meillo@95
|
1406 evaluates to
|
|
meillo@95
|
1407 .Sw -help
|
|
meillo@95
|
1408 for all tools of mmh.
|
|
meillo@95
|
1409
|
|
meillo@95
|
1410
|
|
meillo@95
|
1411 .U3 "Suppressing Edits or the WhatNow Shell
|
|
meillo@95
|
1412 .P
|
|
meillo@95
|
1413 The
|
|
meillo@95
|
1414 .Sw -noedit
|
|
meillo@95
|
1415 switches of
|
|
meillo@95
|
1416 .Pn comp ,
|
|
meillo@95
|
1417 .Pn repl ,
|
|
meillo@95
|
1418 .Pn forw ,
|
|
meillo@95
|
1419 .Pn dist ,
|
|
meillo@95
|
1420 and
|
|
meillo@95
|
1421 .Pn whatnow
|
|
meillo@95
|
1422 was removed, but it can now be replaced by specifying
|
|
meillo@95
|
1423 .Sw -editor
|
|
meillo@95
|
1424 with an empty argument.
|
|
meillo@95
|
1425 (Specifying
|
|
meillo@95
|
1426 .Cl "-editor true
|
|
meillo@95
|
1427 is nearly the same, only differing by the previous editor being set.)
|
|
meillo@95
|
1428 .P
|
|
meillo@95
|
1429 The more important change is the removal of the
|
|
meillo@95
|
1430 .Sw -nowhatnowproc
|
|
meillo@95
|
1431 switch.
|
|
meillo@95
|
1432 This switch had introduced an awkward behavior, as explained in nmh's
|
|
meillo@95
|
1433 man page for
|
|
meillo@95
|
1434 .Mp comp (1):
|
|
meillo@95
|
1435 .QP
|
|
meillo@95
|
1436 The \-editor editor switch indicates the editor to use for
|
|
meillo@95
|
1437 the initial edit. Upon exiting from the editor, comp will
|
|
meillo@95
|
1438 invoke the whatnow program. See whatnow(1) for a discussion
|
|
meillo@95
|
1439 of available options. The invocation of this program can be
|
|
meillo@95
|
1440 inhibited by using the \-nowhatnowproc switch. (In truth of
|
|
meillo@95
|
1441 fact, it is the whatnow program which starts the initial
|
|
meillo@95
|
1442 edit. Hence, \-nowhatnowproc will prevent any edit from
|
|
meillo@95
|
1443 occurring.)
|
|
meillo@95
|
1444 .P
|
|
meillo@95
|
1445 Effectively, the
|
|
meillo@95
|
1446 .Sw -nowhatnowproc
|
|
meillo@95
|
1447 switch stored a copy of the form file into the draft folder.
|
|
meillo@95
|
1448 As
|
|
meillo@95
|
1449 .Cl "-whatnowproc true
|
|
meillo@95
|
1450 causes the same behavior, the
|
|
meillo@95
|
1451 .Sw -nowhatnowproc
|
|
meillo@95
|
1452 switch was removed for being redundant.
|
|
meillo@95
|
1453 Likely, however, the intention for specifying
|
|
meillo@95
|
1454 .Sw -nowhatnowproc
|
|
meillo@95
|
1455 is sending a fully prepared form file at once.
|
|
meillo@95
|
1456 This can be done with
|
|
meillo@95
|
1457 .Cl "-whatnowproc send" .
|
|
meillo@95
|
1458
|
|
meillo@95
|
1459
|
|
meillo@95
|
1460 .U3 "Compatibility Switches
|
|
meillo@95
|
1461 .BU
|
|
meillo@95
|
1462 The hidden
|
|
meillo@95
|
1463 .Sw -[no]total
|
|
meillo@95
|
1464 switches of
|
|
meillo@95
|
1465 .Pn flist .
|
|
meillo@95
|
1466 They were simply the inverse of the visible
|
|
meillo@95
|
1467 .Sw -[no]fast
|
|
meillo@95
|
1468 switches:
|
|
meillo@95
|
1469 .Sw -total
|
|
meillo@95
|
1470 was
|
|
meillo@95
|
1471 .Sw -nofast
|
|
meillo@95
|
1472 and
|
|
meillo@95
|
1473 .Sw -nototal
|
|
meillo@95
|
1474 was
|
|
meillo@95
|
1475 .Sw -fast .
|
|
meillo@95
|
1476 I removed the
|
|
meillo@95
|
1477 .Sw -[no]total
|
|
meillo@95
|
1478 legacy.
|
|
meillo@95
|
1479 .BU
|
|
meillo@95
|
1480 The
|
|
meillo@95
|
1481 .Sw -subject
|
|
meillo@95
|
1482 switch of
|
|
meillo@95
|
1483 .Pn sortm
|
|
meillo@95
|
1484 existed for compatibility only.
|
|
meillo@95
|
1485 It can be fully replaced by
|
|
meillo@95
|
1486 .Cl "-textfield subject
|
|
meillo@95
|
1487 thus it was removed.
|
|
meillo@95
|
1488
|
|
meillo@95
|
1489
|
|
meillo@95
|
1490 .U3 "Various
|
|
meillo@95
|
1491 .BU
|
|
meillo@96
|
1492 In order to avoid prefix collisions among switch names, the
|
|
meillo@95
|
1493 .Sw -version
|
|
meillo@95
|
1494 switch was renamed to
|
|
meillo@95
|
1495 .Sw -Version
|
|
meillo@95
|
1496 (with capital `V').
|
|
meillo@95
|
1497 Every program has the
|
|
meillo@95
|
1498 .Sw -version
|
|
meillo@95
|
1499 switch but its first three letters collided with the
|
|
meillo@95
|
1500 .Sw -verbose
|
|
meillo@95
|
1501 switch, present in many programs.
|
|
meillo@95
|
1502 The rename solved this problem once for all.
|
|
meillo@95
|
1503 Although this rename breaks a basic interface, having the
|
|
meillo@95
|
1504 .Sw -V
|
|
meillo@95
|
1505 abbreviation to display the version information, isn't all too bad.
|
|
meillo@95
|
1506 .BU
|
|
meillo@95
|
1507 .Sw -[no]preserve
|
|
meillo@95
|
1508 of
|
|
meillo@95
|
1509 .Pn refile
|
|
meillo@95
|
1510 was removed because what use was it anyway?
|
|
meillo@95
|
1511 .QP
|
|
meillo@95
|
1512 Normally when a message is refiled, for each destination
|
|
meillo@95
|
1513 folder it is assigned the number which is one above the current
|
|
meillo@95
|
1514 highest message number in that folder. Use of the
|
|
meillo@95
|
1515 \-preserv [sic!] switch will override this message renaming, and try
|
|
meillo@95
|
1516 to preserve the number of the message. If a conflict for a
|
|
meillo@95
|
1517 particular folder occurs when using the \-preserve switch,
|
|
meillo@95
|
1518 then refile will use the next available message number which
|
|
meillo@95
|
1519 is above the message number you wish to preserve.
|
|
meillo@95
|
1520 .BU
|
|
meillo@95
|
1521 The removal of the
|
|
meillo@95
|
1522 .Sw -[no]reverse
|
|
meillo@95
|
1523 switches of
|
|
meillo@95
|
1524 .Pn scan
|
|
meillo@95
|
1525 is a bug fix, supported by the comments
|
|
meillo@95
|
1526 ``\-[no]reverse under #ifdef BERK (I really HATE this)''
|
|
meillo@95
|
1527 by Rose and
|
|
meillo@95
|
1528 ``Lists messages in reverse order with the `\-reverse' switch.
|
|
meillo@95
|
1529 This should be considered a bug.'' by Romine in the documentation.
|
|
meillo@95
|
1530 The question remaining is why neither Rose and Romine had fixed this
|
|
meillo@95
|
1531 bug in the Eighties when they wrote these comments nor has anyone
|
|
meillo@95
|
1532 thereafter.
|
|
meillo@93
|
1533
|
|
meillo@93
|
1534
|
|
meillo@93
|
1535 .ig
|
|
meillo@93
|
1536
|
|
meillo@95
|
1537 forw: [no]dashstuffing(mhl)
|
|
meillo@93
|
1538
|
|
meillo@95
|
1539 mhshow: [no]pause [no]serialonly
|
|
meillo@93
|
1540
|
|
meillo@93
|
1541 mhmail: resent queued
|
|
meillo@93
|
1542 inc: snoop, (pop)
|
|
meillo@93
|
1543
|
|
meillo@95
|
1544 mhl: [no]faceproc folder sleep
|
|
meillo@95
|
1545 [no]dashstuffing(forw) digest list volume number issue number
|
|
meillo@93
|
1546
|
|
meillo@95
|
1547 prompter: [no]doteof
|
|
meillo@93
|
1548
|
|
meillo@93
|
1549 refile: [no]preserve [no]unlink [no]rmmproc
|
|
meillo@93
|
1550
|
|
meillo@95
|
1551 send: [no]forward [no]mime [no]msgid
|
|
meillo@93
|
1552 [no]push split [no]unique (sasl) width snoop [no]dashstuffing
|
|
meillo@93
|
1553 attach attachformat
|
|
meillo@93
|
1554 whatnow: (noedit) attach
|
|
meillo@93
|
1555
|
|
meillo@93
|
1556 slocal: [no]suppressdups
|
|
meillo@93
|
1557
|
|
meillo@95
|
1558 spost: [no]filter [no]backup width [no]push idanno
|
|
meillo@93
|
1559 [no]check(whom) whom(whom)
|
|
meillo@93
|
1560
|
|
meillo@93
|
1561 whom: ???
|
|
meillo@93
|
1562
|
|
meillo@95
|
1563 ..
|
|
meillo@93
|
1564
|
|
meillo@93
|
1565
|
|
meillo@93
|
1566 .ig
|
|
meillo@93
|
1567
|
|
meillo@93
|
1568 .P
|
|
meillo@93
|
1569 To ease typing, the switches can be abbreviated as much as the remaining
|
|
meillo@93
|
1570 prefix remains unambiguous.
|
|
meillo@93
|
1571 If in our example no other switch would start with the letter `t', then
|
|
meillo@93
|
1572 .Cl "-truncate" ,
|
|
meillo@93
|
1573 .Cl "-trunc" ,
|
|
meillo@93
|
1574 .Cl "-tr" ,
|
|
meillo@93
|
1575 and
|
|
meillo@93
|
1576 .Cl "-t
|
|
meillo@93
|
1577 would all be the same.
|
|
meillo@93
|
1578 As a result, switches can neither be grouped (as in
|
|
meillo@93
|
1579 .Cl "ls -ltr" )
|
|
meillo@93
|
1580 nor can switch arguments be appended directly to the switch (as in
|
|
meillo@93
|
1581 .Cl "sendmail -q30m" ).
|
|
meillo@93
|
1582 .P
|
|
meillo@93
|
1583 Many switches have negating counter-parts, which start with `no'.
|
|
meillo@93
|
1584 For example
|
|
meillo@93
|
1585 .Cl "-notruncate
|
|
meillo@93
|
1586 inverts the
|
|
meillo@93
|
1587 .Cl "-truncate
|
|
meillo@93
|
1588 switch.
|
|
meillo@93
|
1589 They exist to undo the effect of default switches in the profile.
|
|
meillo@93
|
1590 If the user has chosen to change the default behavior of some tool
|
|
meillo@93
|
1591 by adding a default switch to the profile,
|
|
meillo@96
|
1592 he can still undo this change in behavior by specifying the inverse
|
|
meillo@93
|
1593 switch on the command line.
|
|
meillo@93
|
1594 .P
|
|
meillo@93
|
1595 In the best case, all switches are unambiguous on the first character,
|
|
meillo@93
|
1596 or on the three-letter prefix for the `no' variants.
|
|
meillo@96
|
1597 Reducing switch prefix collisions, shortens the necessary prefix length
|
|
meillo@93
|
1598 the user must type.
|
|
meillo@93
|
1599 Having less switches helps best.
|
|
meillo@93
|
1600
|
|
meillo@93
|
1601 ..
|
|
meillo@58
|
1602
|
|
meillo@95
|
1603
|
|
meillo@95
|
1604
|
|
meillo@95
|
1605
|
|
meillo@74
|
1606 .H1 "Modernizing
|
|
meillo@58
|
1607
|
|
meillo@58
|
1608
|
|
meillo@58
|
1609 .H2 "Removal of Code Relicts
|
|
meillo@0
|
1610 .P
|
|
meillo@51
|
1611 The code base of mmh originates from the late Seventies,
|
|
meillo@51
|
1612 had been extensively
|
|
meillo@51
|
1613 worked on in the mid Eighties, and had been partly reorganized and extended
|
|
meillo@51
|
1614 in the Nineties. Relicts of all those times had gathered in the code base.
|
|
meillo@12
|
1615 My goal was to remove any ancient code parts. One part of the task was
|
|
meillo@12
|
1616 converting obsolete code constructs to standard constructs, the other part
|
|
meillo@12
|
1617 was dropping obsolete functions.
|
|
meillo@12
|
1618 .P
|
|
meillo@12
|
1619 As I'm not even thirty years old and have no more than seven years of
|
|
meillo@51
|
1620 Unix experience, I needed to learn about the history in retrospective.
|
|
meillo@51
|
1621 Older people likely have used those ancient constructs themselves
|
|
meillo@51
|
1622 and have suffered from their incompatibilities and have longed for
|
|
meillo@12
|
1623 standardization. Unfortunately, I have only read that others had done so.
|
|
meillo@12
|
1624 This put me in a much more difficult positions when working on the old
|
|
meillo@12
|
1625 code. I needed to recherche what other would have known by heart from
|
|
meillo@12
|
1626 experience. All my programming experience comes from a time past ANSI C
|
|
meillo@12
|
1627 and past POSIX. Although I knew about the times before, I took the
|
|
meillo@51
|
1628 current state implicitly for granted most of the time.
|
|
meillo@12
|
1629 .P
|
|
meillo@12
|
1630 Being aware of
|
|
meillo@12
|
1631 these facts, I rather let people with more historic experience solve the
|
|
meillo@12
|
1632 task of converting the ancient code constructs to standardized ones.
|
|
meillo@12
|
1633 Luckily, Lyndon Nerenberg focused on this task at the nmh project.
|
|
meillo@12
|
1634 He converted large parts of the code to POSIX constructs, removing
|
|
meillo@12
|
1635 the conditionals compilation for now standardized features.
|
|
meillo@12
|
1636 I'm thankful for this task being solved. I only pulled the changes into
|
|
meillo@12
|
1637 mmh.
|
|
meillo@12
|
1638 .P
|
|
meillo@20
|
1639 The other task \(en dropping ancient functionality to remove old code \(en
|
|
meillo@12
|
1640 I did myself, though. My position to strip mmh to the bare minimum of
|
|
meillo@12
|
1641 frequently used features is much more revolutional than the nmh community
|
|
meillo@20
|
1642 likes it. Without the need to justify my decisions, I was able to quickly
|
|
meillo@20
|
1643 remove functionality I considered ancient.
|
|
meillo@20
|
1644 The need to discuss my decisions with
|
|
meillo@20
|
1645 peers likely would have slowed this process down. Of course, I researched
|
|
meillo@12
|
1646 if a particular feature really should be dropped. Having not had any
|
|
meillo@12
|
1647 contact to this feature within my computer life was a first indicator to
|
|
meillo@12
|
1648 drop it, but I also asked others and searched the literature for modern
|
|
meillo@12
|
1649 usage of the feature. If it appeared to be truly ancient, I dropped it.
|
|
meillo@12
|
1650 The reason for dropping is always part of the commit message in the
|
|
meillo@12
|
1651 version control system. Thus, it is easy for others to check their
|
|
meillo@12
|
1652 view on the topic with mine and possibly to argue for reinclusion.
|
|
meillo@12
|
1653
|
|
meillo@12
|
1654 .U2 "MMDF maildrop support
|
|
meillo@12
|
1655 .P
|
|
meillo@12
|
1656 I did drop any support for the MMDF maildrop format. This type of format
|
|
meillo@12
|
1657 is conceptionally similar to the mbox format, but uses four bytes with
|
|
meillo@12
|
1658 value 1 (\fL^A^A^A^A\fP) as message delimiter,
|
|
meillo@18
|
1659 instead of the string ``\fLFrom\ \fP''.
|
|
meillo@12
|
1660 Due to the similarity and mbox being the de-facto standard maildrop
|
|
meillo@12
|
1661 format on Unix, but also due to the larger influence of Sendmail than MMDF,
|
|
meillo@12
|
1662 the MMDF maildrop format had vanished.
|
|
meillo@12
|
1663 .P
|
|
meillo@12
|
1664 The simplifications within the code were only moderate. Switches could
|
|
meillo@12
|
1665 be removed from tools like
|
|
meillo@12
|
1666 .L packf ,
|
|
meillo@12
|
1667 which generate packed mailboxes. Only one packed mailbox format remained:
|
|
meillo@12
|
1668 mbox.
|
|
meillo@12
|
1669 The most important changes affect the equally named mail parsing routine in
|
|
meillo@12
|
1670 .L sbr/m_getfld.c .
|
|
meillo@12
|
1671 The direct MMDF code had been removed, but as now only one packed mailbox
|
|
meillo@12
|
1672 format is left, code structure simplifications are likely possible.
|
|
meillo@12
|
1673 The reason why they are still outstanding is the heavily optimized code
|
|
meillo@18
|
1674 of
|
|
meillo@18
|
1675 .Fu m_getfld() .
|
|
meillo@18
|
1676 Changes beyond a small local scope \(en
|
|
meillo@12
|
1677 which restructuring in its core is \(en cause a high risk of damaging
|
|
meillo@12
|
1678 the intricate workings of the optimized code. This problem is know
|
|
meillo@12
|
1679 to the developers of nmh, too. They also avoid touching this minefield
|
|
meillo@12
|
1680 if possible.
|
|
meillo@12
|
1681
|
|
meillo@12
|
1682 .U2 "UUCP Bang Paths
|
|
meillo@12
|
1683 .P
|
|
meillo@12
|
1684 More questionably than the former topic is the removal of support for the
|
|
meillo@12
|
1685 UUCP bang path address style. However, the user may translate the bang
|
|
meillo@12
|
1686 paths on retrieval to Internet addresses and the other way on posting
|
|
meillo@12
|
1687 messages. The former can be done my an MDA like procmail; the latter
|
|
meillo@12
|
1688 by a sendmail wrapper. This would ensure that any address handling would
|
|
meillo@12
|
1689 work as expected. However, it might just work well without any
|
|
meillo@12
|
1690 such modifications, as mmh does not touch addresses much, in general.
|
|
meillo@12
|
1691 But I can't ensure as I have never used an environment with bang paths.
|
|
meillo@12
|
1692 Also, the behavior might break at any point in further development.
|
|
meillo@12
|
1693
|
|
meillo@12
|
1694 .U2 "Hardcopy terminal support
|
|
meillo@12
|
1695 .P
|
|
meillo@12
|
1696 More of a funny anecdote is the remaining of a check for printing to a
|
|
meillo@12
|
1697 hardcopy terminal until Spring 2012, when I finally removed it.
|
|
meillo@12
|
1698 I surely would be very happy to see such a terminal in action, maybe
|
|
meillo@12
|
1699 actually being able to work on it, but I fear my chances are null.
|
|
meillo@12
|
1700 .P
|
|
meillo@12
|
1701 The check only prevented a pager to be placed between the outputting
|
|
meillo@18
|
1702 program (\c
|
|
meillo@18
|
1703 .Pn mhl )
|
|
meillo@18
|
1704 and the terminal. This could have been ensured with
|
|
meillo@18
|
1705 the
|
|
meillo@82
|
1706 .Sw -nomoreproc
|
|
meillo@18
|
1707 at the command line statically, too.
|
|
meillo@12
|
1708
|
|
meillo@12
|
1709 .U2 "Removed support for header fields
|
|
meillo@12
|
1710 .P
|
|
meillo@84
|
1711 The
|
|
meillo@84
|
1712 .Hd Encrypted
|
|
meillo@84
|
1713 header field had been introduced by RFC\^822, but already
|
|
meillo@12
|
1714 marked legacy in RFC 2822. It was superseded by FIXME.
|
|
meillo@84
|
1715 Mmh does no more support this header field.
|
|
meillo@12
|
1716 .P
|
|
meillo@84
|
1717 Native support for
|
|
meillo@84
|
1718 .Hd Face
|
|
meillo@84
|
1719 header fields had been removed, as well.
|
|
meillo@84
|
1720 The feature is similar to the
|
|
meillo@84
|
1721 .Hd X-Face
|
|
meillo@84
|
1722 header field in its intent,
|
|
meillo@21
|
1723 but takes a different approach to store the image.
|
|
meillo@84
|
1724 Instead of encoding the image data directly into the header field,
|
|
meillo@84
|
1725 the it contains the hostname and UDP port where the image
|
|
meillo@21
|
1726 date could be retrieved.
|
|
meillo@84
|
1727 Neither
|
|
meillo@84
|
1728 .Hd X-Face
|
|
meillo@84
|
1729 nor the here described
|
|
meillo@84
|
1730 .Hd Face
|
|
meillo@84
|
1731 system
|
|
meillo@21
|
1732 \**
|
|
meillo@21
|
1733 .FS
|
|
meillo@21
|
1734 There is also a newer but different system, invented 2005,
|
|
meillo@84
|
1735 using
|
|
meillo@84
|
1736 .Hd Face
|
|
meillo@84
|
1737 headers.
|
|
meillo@84
|
1738 It is the successor of
|
|
meillo@84
|
1739 .Hd X-Face
|
|
meillo@84
|
1740 providing colored PNG images.
|
|
meillo@21
|
1741 .FE
|
|
meillo@21
|
1742 became well used in the large scale.
|
|
meillo@21
|
1743 It's still possible to use a Face systems,
|
|
meillo@21
|
1744 although mmh does not provide support for any of the different systems
|
|
meillo@21
|
1745 anymore. It's fairly easy to write a small shell script to
|
|
meillo@21
|
1746 extract the embedded or fetch the external Face data and display the image.
|
|
meillo@84
|
1747 Own
|
|
meillo@84
|
1748 .Hd Face
|
|
meillo@84
|
1749 header field can be added into the draft template files.
|
|
meillo@21
|
1750 .P
|
|
meillo@84
|
1751 .Hd Content-MD5
|
|
meillo@84
|
1752 header fields were introduced by RFC\^1864. They provide only
|
|
meillo@12
|
1753 a verification of data corruption during the transfer. By no means can
|
|
meillo@12
|
1754 they ensure verbatim end-to-end delivery of the contents. This is clearly
|
|
meillo@12
|
1755 stated in the RFC. The proper approach to provide verificationability
|
|
meillo@12
|
1756 of content in an end-to-end relationship is the use of digital cryptography
|
|
meillo@12
|
1757 (RFCs FIXME). On the other hand, transfer protocols should ensure the
|
|
meillo@12
|
1758 integrity of the transmission. In combinations these two approaches
|
|
meillo@84
|
1759 make the
|
|
meillo@84
|
1760 .Hd Content-MD5
|
|
meillo@84
|
1761 header field useless. In consequence, I removed
|
|
meillo@12
|
1762 the support for it. By this removal, MD5 computation is not needed
|
|
meillo@12
|
1763 anywhere in mmh. Hence, over 500 lines of code were removed by this one
|
|
meillo@84
|
1764 change. Even if the
|
|
meillo@84
|
1765 .Hd Content-MD5
|
|
meillo@84
|
1766 header field is useful sometimes,
|
|
meillo@89
|
1767 I value its usefulness less than the improvement in maintainability, caused
|
|
meillo@12
|
1768 by the removal.
|
|
meillo@12
|
1769
|
|
meillo@20
|
1770 .U2 "Prompter's Control Keys
|
|
meillo@20
|
1771 .P
|
|
meillo@20
|
1772 The program
|
|
meillo@20
|
1773 .Pn prompter
|
|
meillo@20
|
1774 queries the user to fill in a message form. When used by
|
|
meillo@20
|
1775 .Pn comp
|
|
meillo@20
|
1776 as:
|
|
meillo@82
|
1777 .VS
|
|
meillo@82
|
1778 comp -editor prompter
|
|
meillo@82
|
1779 VE
|
|
meillo@20
|
1780 the resulting behavior is similar to
|
|
meillo@20
|
1781 .Pn mailx .
|
|
meillo@51
|
1782 Apparently,
|
|
meillo@20
|
1783 .Pn prompter
|
|
meillo@20
|
1784 hadn't been touched lately. Otherwise it's hardly explainable why it
|
|
meillo@20
|
1785 still offered the switches
|
|
meillo@84
|
1786 .Sw -erase
|
|
meillo@84
|
1787 .Ar chr
|
|
meillo@20
|
1788 and
|
|
meillo@84
|
1789 .Sw -kill
|
|
meillo@84
|
1790 .Ar chr
|
|
meillo@20
|
1791 to name the characters for command line editing.
|
|
meillo@21
|
1792 The times when this had been necessary are long time gone.
|
|
meillo@20
|
1793 Today these things work out-of-the-box, and if not, are configured
|
|
meillo@20
|
1794 with the standard tool
|
|
meillo@20
|
1795 .Pn stty .
|
|
meillo@20
|
1796
|
|
meillo@21
|
1797 .U2 "Vfork and Retry Loops
|
|
meillo@21
|
1798 .P
|
|
meillo@51
|
1799 MH creates many processes, which is a consequence of the tool chest approach.
|
|
meillo@21
|
1800 In earlier times
|
|
meillo@21
|
1801 .Fu fork()
|
|
meillo@21
|
1802 had been an expensive system call, as the process's whole image needed
|
|
meillo@21
|
1803 to be duplicated. One common case is replacing the image with
|
|
meillo@21
|
1804 .Fu exec()
|
|
meillo@21
|
1805 right after having forked the child process.
|
|
meillo@21
|
1806 To speed up this case, the
|
|
meillo@21
|
1807 .Fu vfork()
|
|
meillo@21
|
1808 system call was invented at Berkeley. It completely omits copying the
|
|
meillo@21
|
1809 image. If the image gets replaced right afterwards then unnecessary
|
|
meillo@21
|
1810 work is omited. On old systems this results in large speed ups.
|
|
meillo@21
|
1811 MH uses
|
|
meillo@21
|
1812 .Fu vfork()
|
|
meillo@21
|
1813 whenever possible.
|
|
meillo@21
|
1814 .P
|
|
meillo@21
|
1815 Memory management units that support copy-on-write semantics make
|
|
meillo@21
|
1816 .Fu fork()
|
|
meillo@21
|
1817 almost as fast as
|
|
meillo@21
|
1818 .Fu vfork()
|
|
meillo@21
|
1819 in the cases when they can be exchanged.
|
|
meillo@21
|
1820 With
|
|
meillo@21
|
1821 .Fu vfork()
|
|
meillo@51
|
1822 being more error-prone and hardly faster, it's preferable to simply
|
|
meillo@21
|
1823 use
|
|
meillo@21
|
1824 .Fu fork()
|
|
meillo@21
|
1825 instead.
|
|
meillo@21
|
1826 .P
|
|
meillo@21
|
1827 Related to the costs of
|
|
meillo@21
|
1828 .Fu fork()
|
|
meillo@21
|
1829 is the probability of its success.
|
|
meillo@21
|
1830 Today on modern systems, the system call will succeed almost always.
|
|
meillo@51
|
1831 In the Eighties on heavy loaded systems, as they were common at
|
|
meillo@21
|
1832 universities, this had been different. Thus, many of the
|
|
meillo@21
|
1833 .Fu fork()
|
|
meillo@21
|
1834 calls were wrapped into loops to retry to fork several times in
|
|
meillo@21
|
1835 short intervals, in case of previous failure.
|
|
meillo@21
|
1836 In mmh, the program aborts at once if the fork failed.
|
|
meillo@21
|
1837 The user can reexecute the command then. This is expected to be a
|
|
meillo@21
|
1838 very rare case on modern systems, especially personal ones, which are
|
|
meillo@21
|
1839 common today.
|
|
meillo@21
|
1840
|
|
meillo@12
|
1841
|
|
meillo@58
|
1842 .H2 "Attachments
|
|
meillo@22
|
1843 .P
|
|
meillo@58
|
1844 MIME
|
|
meillo@58
|
1845
|
|
meillo@58
|
1846
|
|
meillo@58
|
1847 .H2 "Digital Cryptography
|
|
meillo@22
|
1848 .P
|
|
meillo@58
|
1849 Signing and encryption.
|
|
meillo@58
|
1850
|
|
meillo@58
|
1851
|
|
meillo@58
|
1852 .H2 "Good Defaults
|
|
meillo@22
|
1853 .P
|
|
meillo@58
|
1854 foo
|
|
meillo@58
|
1855
|
|
meillo@58
|
1856
|
|
meillo@58
|
1857
|
|
meillo@58
|
1858
|
|
meillo@58
|
1859 .H1 "Code style
|
|
meillo@22
|
1860 .P
|
|
meillo@58
|
1861 foo
|
|
meillo@58
|
1862
|
|
meillo@58
|
1863
|
|
meillo@58
|
1864 .H2 "Standard Code
|
|
meillo@22
|
1865 .P
|
|
meillo@58
|
1866 POSIX
|
|
meillo@22
|
1867
|
|
meillo@22
|
1868
|
|
meillo@58
|
1869 .H2 "Separation
|
|
meillo@14
|
1870
|
|
meillo@58
|
1871 .U2 "MH Directory Split
|
|
meillo@0
|
1872 .P
|
|
meillo@19
|
1873 In MH and nmh, a personal setup had consisted of two parts:
|
|
meillo@19
|
1874 The MH profile, named
|
|
meillo@19
|
1875 .Fn \&.mh_profile
|
|
meillo@19
|
1876 and being located directly in the user's home directory.
|
|
meillo@19
|
1877 And the MH directory, where all his mail messages and also his personal
|
|
meillo@19
|
1878 forms, scan formats, other configuration files are stored. The location
|
|
meillo@19
|
1879 of this directory could be user-chosen. The default was to name it
|
|
meillo@19
|
1880 .Fn Mail
|
|
meillo@19
|
1881 and have it directly in the home directory.
|
|
meillo@19
|
1882 .P
|
|
meillo@19
|
1883 I've never liked the data storage and the configuration to be intermixed.
|
|
meillo@19
|
1884 They are different kinds of data. One part, are the messages,
|
|
meillo@19
|
1885 which are the data to operate on. The other part, are the personal
|
|
meillo@19
|
1886 configuration files, which are able to change the behavior of the operations.
|
|
meillo@19
|
1887 The actual operations are defined in the profile, however.
|
|
meillo@19
|
1888 .P
|
|
meillo@19
|
1889 When storing data, one should try to group data by its type.
|
|
meillo@19
|
1890 There's sense in the Unix file system hierarchy, where configuration
|
|
meillo@19
|
1891 file are stored separate (\c
|
|
meillo@19
|
1892 .Fn /etc )
|
|
meillo@19
|
1893 to the programs (\c
|
|
meillo@19
|
1894 .Fn /bin
|
|
meillo@19
|
1895 and
|
|
meillo@19
|
1896 .Fn /usr/bin )
|
|
meillo@19
|
1897 to their sources (\c
|
|
meillo@19
|
1898 .Fn /usr/src ).
|
|
meillo@19
|
1899 Such separation eases the backup management, for instance.
|
|
meillo@19
|
1900 .P
|
|
meillo@19
|
1901 In mmh, I've reorganized the file locations.
|
|
meillo@19
|
1902 Still there are two places:
|
|
meillo@19
|
1903 There's the mail storage directory, which, like in MH, contains all the
|
|
meillo@19
|
1904 messages, but, unlike in MH, nothing else.
|
|
meillo@19
|
1905 Its location still is user-chosen, with the default name
|
|
meillo@19
|
1906 .Fn Mail ,
|
|
meillo@19
|
1907 in the user's home directory. This is much similar to the case in nmh.
|
|
meillo@19
|
1908 The configuration files, however, are grouped together in the new directory
|
|
meillo@19
|
1909 .Fn \&.mmh
|
|
meillo@19
|
1910 in the user's home directory.
|
|
meillo@19
|
1911 The user's profile now is a file, named
|
|
meillo@19
|
1912 .Fn profile ,
|
|
meillo@19
|
1913 in this mmh directory.
|
|
meillo@19
|
1914 Consistently, the context file and all the personal forms, scan formats,
|
|
meillo@19
|
1915 and the like, are also there.
|
|
meillo@19
|
1916 .P
|
|
meillo@19
|
1917 The naming changed with the relocation.
|
|
meillo@19
|
1918 The directory where everything, except the profile, had been stored (\c
|
|
meillo@19
|
1919 .Fn $HOME/Mail ),
|
|
meillo@19
|
1920 used to be called \fIMH directory\fP. Now, this directory is called the
|
|
meillo@19
|
1921 user's \fImail storage\fP. The name \fImmh directory\fP is now given to
|
|
meillo@19
|
1922 the new directory
|
|
meillo@19
|
1923 (\c
|
|
meillo@19
|
1924 .Fn $HOME/.mmh ),
|
|
meillo@19
|
1925 containing all the personal configuration files.
|
|
meillo@19
|
1926 .P
|
|
meillo@19
|
1927 The separation of the files by type of content is logical and convenient.
|
|
meillo@19
|
1928 There are no functional differences as any possible setup known to me
|
|
meillo@19
|
1929 can be implemented with both approaches, although likely a bit easier
|
|
meillo@19
|
1930 with the new approach. The main goal of the change had been to provide
|
|
meillo@19
|
1931 sensible storage locations for any type of personal mmh file.
|
|
meillo@19
|
1932 .P
|
|
meillo@19
|
1933 In order for one user to have multiple MH setups, he can use the
|
|
meillo@19
|
1934 environment variable
|
|
meillo@19
|
1935 .Ev MH
|
|
meillo@19
|
1936 the point to a different profile file.
|
|
meillo@19
|
1937 The MH directory (mail storage plus personal configuration files) is
|
|
meillo@19
|
1938 defined by the
|
|
meillo@19
|
1939 .Pe Path
|
|
meillo@19
|
1940 profile entry.
|
|
meillo@19
|
1941 The context file could be defined by the
|
|
meillo@19
|
1942 .Pe context
|
|
meillo@19
|
1943 profile entry or by the
|
|
meillo@19
|
1944 .Ev MHCONTEXT
|
|
meillo@19
|
1945 environment variable.
|
|
meillo@19
|
1946 The latter is useful to have a distinct context (e.g. current folders)
|
|
meillo@19
|
1947 in each terminal window, for instance.
|
|
meillo@19
|
1948 In mmh, there are three environment variables now.
|
|
meillo@19
|
1949 .Ev MMH
|
|
meillo@19
|
1950 may be used to change the location of the mmh directory.
|
|
meillo@19
|
1951 .Ev MMHP
|
|
meillo@19
|
1952 and
|
|
meillo@19
|
1953 .Ev MMHC
|
|
meillo@19
|
1954 change the profile and context files, respectively.
|
|
meillo@19
|
1955 Besides providing a more consistent feel (which simply is the result
|
|
meillo@19
|
1956 of being designed anew), the set of personal configuration files can
|
|
meillo@19
|
1957 be chosen independently from the profile (including mail storage location)
|
|
meillo@19
|
1958 and context, now. Being it relevant for practical use or not, it
|
|
meillo@19
|
1959 de-facto is an improvement. However, the main achievement is the
|
|
meillo@19
|
1960 split between mail storage and personal configuration files.
|
|
meillo@17
|
1961
|
|
meillo@0
|
1962
|
|
meillo@58
|
1963 .H2 "Modularization
|
|
meillo@0
|
1964 .P
|
|
meillo@58
|
1965 whatnowproc
|
|
meillo@0
|
1966 .P
|
|
meillo@49
|
1967 The \fIMH library\fP
|
|
meillo@49
|
1968 .Fn libmh.a
|
|
meillo@49
|
1969 collects a bunch of standard functions that many of the MH tools need,
|
|
meillo@49
|
1970 like reading the profile or context files.
|
|
meillo@49
|
1971 This doesn't hurt the separation.
|
|
meillo@49
|
1972
|
|
meillo@58
|
1973
|
|
meillo@58
|
1974 .H2 "Style
|
|
meillo@58
|
1975 .P
|
|
meillo@58
|
1976 Code layout, goto, ...
|
|
meillo@58
|
1977
|
|
meillo@58
|
1978
|
|
meillo@58
|
1979
|
|
meillo@58
|
1980
|
|
meillo@89
|
1981 .H1 "Concept Exploitation/Homogeneity
|
|
meillo@58
|
1982
|
|
meillo@58
|
1983
|
|
meillo@58
|
1984 .H2 "Draft Folder
|
|
meillo@58
|
1985 .P
|
|
meillo@58
|
1986 Historically, MH provided exactly one draft message, named
|
|
meillo@58
|
1987 .Fn draft
|
|
meillo@58
|
1988 and
|
|
meillo@58
|
1989 being located in the MH directory. When starting to compose another message
|
|
meillo@58
|
1990 before the former one was sent, the user had been questioned whether to use,
|
|
meillo@58
|
1991 refile or replace the old draft. Working on multiple drafts at the same time
|
|
meillo@58
|
1992 was impossible. One could only work on them in alteration by refiling the
|
|
meillo@58
|
1993 previous one to some directory and fetching some other one for reediting.
|
|
meillo@58
|
1994 This manual draft management needed to be done each time the user wanted
|
|
meillo@58
|
1995 to switch between editing one draft to editing another.
|
|
meillo@58
|
1996 .P
|
|
meillo@58
|
1997 To allow true parallel editing of drafts, in a straight forward way, the
|
|
meillo@58
|
1998 draft folder facility exists. It had been introduced already in July 1984
|
|
meillo@58
|
1999 by Marshall T. Rose. The facility was deactivated by default.
|
|
meillo@58
|
2000 Even in nmh, the draft folder facility remained deactivated by default.
|
|
meillo@58
|
2001 At least, Richard Coleman added the man page
|
|
meillo@58
|
2002 .Mp mh-draft(5)
|
|
meillo@58
|
2003 to document
|
|
meillo@58
|
2004 the feature well.
|
|
meillo@58
|
2005 .P
|
|
meillo@58
|
2006 The only advantage of not using the draft folder facility is the static
|
|
meillo@89
|
2007 name of the draft file. This could be an issue for MH front-ends like mh-e.
|
|
meillo@58
|
2008 But as they likely want to provide working on multiple drafts in parallel,
|
|
meillo@58
|
2009 the issue is only concerning compatibility. The aim of nmh to stay compatible
|
|
meillo@58
|
2010 prevented the default activation of the draft folder facility.
|
|
meillo@58
|
2011 .P
|
|
meillo@58
|
2012 On the other hand, a draft folder is the much more natural concept than
|
|
meillo@58
|
2013 a draft message. MH's mail storage consists of folders and messages,
|
|
meillo@58
|
2014 the messages named with ascending numbers. A draft message breaks with this
|
|
meillo@58
|
2015 concept by introducing a message in a file named
|
|
meillo@58
|
2016 .Fn draft .
|
|
meillo@58
|
2017 This draft
|
|
meillo@58
|
2018 message is special. It can not be simply listed with the available tools,
|
|
meillo@58
|
2019 but instead requires special switches. I.e. corner-cases were
|
|
meillo@58
|
2020 introduced. A draft folder, in contrast, does not introduce such
|
|
meillo@58
|
2021 corner-cases. The available tools can operate on the messages within that
|
|
meillo@58
|
2022 folder like on any messages within any mail folders. The only difference
|
|
meillo@58
|
2023 is the fact that the default folder for
|
|
meillo@58
|
2024 .Pn send
|
|
meillo@58
|
2025 is the draft folder,
|
|
meillo@58
|
2026 instead of the current folder, like for all other tools.
|
|
meillo@58
|
2027 .P
|
|
meillo@58
|
2028 The trivial part of the change was activating the draft folder facility
|
|
meillo@58
|
2029 by default and setting a default name for this folder. Obviously, I chose
|
|
meillo@58
|
2030 the name
|
|
meillo@58
|
2031 .Fn +drafts .
|
|
meillo@58
|
2032 This made the
|
|
meillo@82
|
2033 .Sw -draftfolder
|
|
meillo@58
|
2034 and
|
|
meillo@82
|
2035 .Sw -draftmessage
|
|
meillo@58
|
2036 switches useless, and I could remove them.
|
|
meillo@58
|
2037 The more difficult but also the part that showed the real improvement,
|
|
meillo@58
|
2038 was updating the tools to the new concept.
|
|
meillo@82
|
2039 .Sw -draft
|
|
meillo@58
|
2040 switches could
|
|
meillo@58
|
2041 be dropped, as operating on a draft message became indistinguishable to
|
|
meillo@58
|
2042 operating on any other message for the tools.
|
|
meillo@58
|
2043 .Pn comp
|
|
meillo@58
|
2044 still has its
|
|
meillo@82
|
2045 .Sw -use
|
|
meillo@58
|
2046 switch for switching between its two modes: (1) Compose a new
|
|
meillo@58
|
2047 draft, possibly by taking some existing message as a form. (2) Modify
|
|
meillo@58
|
2048 an existing draft. In either case, the behavior of
|
|
meillo@58
|
2049 .Pn comp is
|
|
meillo@58
|
2050 deterministic. There is no more need to query the user. I consider this
|
|
meillo@58
|
2051 a major improvement. By making
|
|
meillo@58
|
2052 .Pn send
|
|
meillo@58
|
2053 simply operate on the current
|
|
meillo@58
|
2054 message in the draft folder by default, with message and folder both
|
|
meillo@58
|
2055 overridable by specifying them on the command line, it is now possible
|
|
meillo@58
|
2056 to send a draft anywhere within the storage by simply specifying its folder
|
|
meillo@58
|
2057 and name.
|
|
meillo@58
|
2058 .P
|
|
meillo@58
|
2059 All theses changes converted special cases to regular cases, thus
|
|
meillo@58
|
2060 simplifying the tools and increasing the flexibility.
|
|
meillo@58
|
2061
|
|
meillo@58
|
2062
|
|
meillo@58
|
2063 .H2 "Trash Folder
|
|
meillo@58
|
2064 .P
|
|
meillo@58
|
2065 Similar to the situation for drafts is the situation for removed messages.
|
|
meillo@58
|
2066 Historically, a message was deleted by renaming. A specific
|
|
meillo@58
|
2067 \fIbackup prefix\fP, often comma (\c
|
|
meillo@58
|
2068 .Fn , )
|
|
meillo@58
|
2069 or hash (\c
|
|
meillo@58
|
2070 .Fn # ),
|
|
meillo@58
|
2071 being prepended to the file name. Thus, MH wouldn't recognize the file
|
|
meillo@58
|
2072 as a message anymore, as only files whose name consists of digits only
|
|
meillo@58
|
2073 are treated as messages. The removed messages remained as files in the
|
|
meillo@58
|
2074 same directory and needed some maintenance job to truly delete them after
|
|
meillo@58
|
2075 some grace time. Usually, by running a command similar to
|
|
meillo@82
|
2076 .VS
|
|
meillo@82
|
2077 find /home/user/Mail -ctime +7 -name ',*' | xargs rm
|
|
meillo@82
|
2078 VE
|
|
meillo@58
|
2079 in a cron job. Within the grace time interval
|
|
meillo@58
|
2080 the original message could be restored by stripping the
|
|
meillo@58
|
2081 the backup prefix from the file name. If however, the last message of
|
|
meillo@58
|
2082 a folder is been removed \(en say message
|
|
meillo@58
|
2083 .Fn 6
|
|
meillo@58
|
2084 becomes file
|
|
meillo@58
|
2085 .Fn ,6
|
|
meillo@58
|
2086 \(en and a new message enters the same folder, thus the same
|
|
meillo@58
|
2087 numbered being given again \(en in our case
|
|
meillo@58
|
2088 .Fn 6
|
|
meillo@58
|
2089 \(en, if that one
|
|
meillo@58
|
2090 is removed too, then the backup of the former message gets overwritten.
|
|
meillo@58
|
2091 Thus, the ability to restore removed messages does not only depend on
|
|
meillo@58
|
2092 the ``sweeping cron job'' but also on the removing of further messages.
|
|
meillo@58
|
2093 This is undesirable, because the real mechanism is hidden from the user
|
|
meillo@58
|
2094 and the consequences of further removals are not always obvious.
|
|
meillo@58
|
2095 Further more, the backup files are scattered within the whole mail
|
|
meillo@58
|
2096 storage, instead of being collected at one place.
|
|
meillo@58
|
2097 .P
|
|
meillo@58
|
2098 To improve the situation, the profile entry
|
|
meillo@58
|
2099 .Pe rmmproc
|
|
meillo@58
|
2100 (previously named
|
|
meillo@58
|
2101 .Pe Delete-Prog )
|
|
meillo@58
|
2102 was introduced, very early.
|
|
meillo@58
|
2103 It could be set to any command, which would care for the mail removal
|
|
meillo@58
|
2104 instead of taking the default action, described above.
|
|
meillo@58
|
2105 Refiling the to-be-removed files to some garbage folder was a common
|
|
meillo@58
|
2106 example. Nmh's man page
|
|
meillo@58
|
2107 .Mp rmm(1)
|
|
meillo@58
|
2108 proposes
|
|
meillo@58
|
2109 .Cl "refile +d
|
|
meillo@58
|
2110 to move messages to the garbage folder and
|
|
meillo@58
|
2111 .Cl "rm `mhpath +d all`
|
|
meillo@58
|
2112 the empty the garbage folder.
|
|
meillo@58
|
2113 Managing the message removal this way is a sane approach. It keeps
|
|
meillo@58
|
2114 the removed messages in one place, makes it easy to remove the backup
|
|
meillo@58
|
2115 files, and, most important, enables the user to use the tools of MH
|
|
meillo@58
|
2116 itself to operate on the removed messages. One can
|
|
meillo@58
|
2117 .Pn scan
|
|
meillo@58
|
2118 them,
|
|
meillo@58
|
2119 .Pn show
|
|
meillo@58
|
2120 them, and restore them with
|
|
meillo@58
|
2121 .Pn refile .
|
|
meillo@58
|
2122 There's no more
|
|
meillo@58
|
2123 need to use
|
|
meillo@58
|
2124 .Pn mhpath
|
|
meillo@58
|
2125 to switch over from MH tools to Unix tools \(en MH can do it all itself.
|
|
meillo@58
|
2126 .P
|
|
meillo@58
|
2127 This approach matches perfect with the concepts of MH, thus making
|
|
meillo@58
|
2128 it powerful. Hence, I made it the default. And even more, I also
|
|
meillo@58
|
2129 removed the old backup prefix approach, as it is clearly less powerful.
|
|
meillo@58
|
2130 Keeping unused alternative in the code is a bad choice as they likely
|
|
meillo@58
|
2131 gather bugs, by not being constantly tested. Also, the increased code
|
|
meillo@58
|
2132 size and more conditions crease the maintenance costs. By strictly
|
|
meillo@58
|
2133 converting to the trash folder approach, I simplified the code base.
|
|
meillo@58
|
2134 .Pn rmm
|
|
meillo@58
|
2135 calls
|
|
meillo@58
|
2136 .Pn refile
|
|
meillo@58
|
2137 internally to move the to-be-removed
|
|
meillo@58
|
2138 message to the trash folder (\c
|
|
meillo@58
|
2139 .Fn +trash
|
|
meillo@58
|
2140 by default). Messages
|
|
meillo@58
|
2141 there can be operated on like on any other message in the storage.
|
|
meillo@58
|
2142 The sweep clean, one can use
|
|
meillo@82
|
2143 .Cl "rmm -unlink +trash a" ,
|
|
meillo@58
|
2144 where the
|
|
meillo@82
|
2145 .Sw -unlink
|
|
meillo@58
|
2146 switch causes the files to be truly unliked instead
|
|
meillo@58
|
2147 of moved to the trash folder.
|
|
meillo@58
|
2148
|
|
meillo@58
|
2149
|
|
meillo@58
|
2150 .H2 "Path Notations
|
|
meillo@58
|
2151 .P
|
|
meillo@58
|
2152 foo
|
|
meillo@58
|
2153
|
|
meillo@58
|
2154
|
|
meillo@58
|
2155 .H2 "MIME Integration
|
|
meillo@58
|
2156 .P
|
|
meillo@58
|
2157 user-visible access to whole messages and MIME parts are inherently
|
|
meillo@58
|
2158 different
|
|
meillo@58
|
2159
|
|
meillo@58
|
2160
|
|
meillo@58
|
2161 .H2 "Of One Cast
|
|
meillo@58
|
2162 .P
|
