1MHLIST(1) General Commands Manual MHLIST(1)
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6 mhlist - list information about nmh MIME messages
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9 mhlist [-help] [-version] [+folder] [msgs] [-file file] [-part number]
10 ... [-type content] ... [-prefer content] ... [-noprefer]
11 [-headers | -noheaders] [-realsize | -norealsize] [-rcache policy]
12 [-wcache policy] [-check | -nocheck] [-changecur | -nochangecur]
13 [-verbose | -noverbose] [-disposition | -nodisposition]
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16 The mhlist command allows you to list information (a table of contents,
17 essentially) about the various parts of a collection of MIME (multi-
18 media) messages.
19 mhlist manipulates MIME messages as specified in RFC 2045 to RFC 2049
21 (See mhbuild(1)).
22 The -headers switch indicates that a one-line banner should be dis‐
24 played above the listing (the default).
25 The -realsize switch tells mhlist to evaluate the “native” (decoded)
27 format of each content prior to listing. This provides an accurate
28 count at the expense of a small delay. In either case, sizes will be
29 expressed using SI prefix abbreviations (K/M/G/T), which are based on
30 factors of 1000.
31 If the -verbose switch is present, then the listing will show any
33 “extra” information that is present in the message, such as comments in
34 the “Content-Type” header.
35 If the -disposition switch is present, then the listing will show any
37 relevant information from the “Content-Disposition” header.
38 The option -file file directs mhlist to use the specified file as the
40 source message, rather than a message from a folder. If you specify
41 this file as “-”, then mhlist will accept the source message on the
42 standard input. Note that the file, or input from standard input
43 should be a validly formatted message, just like any other nmh message.
44 It should not be in mail drop format (to convert a file in mail drop
45 format to a folder of nmh messages, see inc(1)).
46 By default, mhlist will list information about the entire message (all
48 of its parts). By using the -part, -type, and -prefer switches, you
49 may limit and reorder the set of parts to be listed, based on part num‐
50 ber and/or content type.
51 A part specification consists of a series of numbers separated by dots.
53 For example, in a multipart content containing three parts, these would
54 be named as 1, 2, and 3, respectively. If part 2 was also a multipart
55 content containing two parts, these would be named as 2.1 and 2.2,
56 respectively. Note that the -part switch is effective only for mes‐
57 sages containing a multipart content. If a message has some other kind
58 of content, or if the part is itself another multipart content, the
59 -part switch will not prevent the content from being acted upon.
60 The -type switch can also be used to restrict (or, when used in con‐
62 junction with -part, to further restrict) the selection of parts
63 according to content type. One or more -type switches part will only
64 select the first match from a multipart/alternative, even if there is
65 more than one subpart that matches (one of) the given content type(s).
66 Using either -part or -type switches alone will cause either to select
68 the part(s) they match. Using them together will select only the
69 part(s) matched by both (sets of) switches. In other words, the result
70 is the intersection, and not the union, of their separate match
71 results.
72 A content specification consists of a content type and a subtype. The
74 initial list of “standard” content types and subtypes can be found in
75 RFC 2046.
76 A list of commonly used contents is briefly reproduced here:
78 Type Subtypes
80 ---- --------
81 text plain, enriched
82 multipart mixed, alternative, digest, parallel
83 message rfc822, partial, external-body
84 application octet-stream, postscript
85 image jpeg, gif, png
86 audio basic
87 video mpeg
88 A legal MIME message must contain a subtype specification.
90 To specify a content, regardless of its subtype, just use the name of
92 the content, e.g., “audio”. To specify a specific subtype, separate
93 the two with a slash, e.g., “audio/basic”. Note that regardless of the
94 values given to the -type switch, a multipart content (of any subtype
95 listed above) is always acted upon. Further note that if the -type
96 switch is used, and it is desirable to act on a message/external-body
97 content, then the -type switch must be used twice: once for mes‐
98 sage/external-body and once for the content externally referenced.
99 By default, the parts of a multipart/alternative part are listed in the
101 reverse order of their placement in the message. The listing, there‐
102 fore, is in decreasing order of preference, as defined in RFC 2046.
103 The -prefer switch can be used (one or more times, in order of ascend‐
104 ing preference) to let MH know which content types from a multi‐
105 part/alternative MIME part are preferred by the user, in order to over‐
106 ride the default preference order. Thus, when viewed by mhlist, the
107 ordering of multipart/alternative parts will appear to change when
108 invoked with or without various -prefer switches. The -noprefer switch
109 will cancel any previous -prefer switches. The -prefer and -noprefer
110 switches are functionally most important for mhshow, but are also
111 implemented in mhlist and mhstore to make common part numbering possi‐
112 ble across all three programs.
113 Checking the Contents
115 The -check switch tells mhlist to check each content for an integrity
116 checksum. If a content has such a checksum (specified as a Content-MD5
117 header field), then mhlist will attempt to verify the integrity of the
118 content.
119
121 $HOME/.mh_profile The user profile
122
124 Path: To determine the user's nmh directory
125 Current-Folder: To find the default current folder
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128 mhbuild(1), mhshow(1), mhstore(1)
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131 `+folder' defaults to the current folder
132 `msgs' defaults to cur
133 `-nocheck'
134 `-headers'
135 `-realsize'
136 `-rcache ask'
137 `-wcache ask'
138 `-changecur'
139 `-noverbose'
140 `-nodisposition'
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143 If a folder is given, it will become the current folder. The last mes‐
144 sage selected will become the current message, unless the -nochangecur
145 option is specified.
146nmh-1.7.1 2015-02-06 MHLIST(1)