mhlist − list information about MIME messages
mhlist |
[+folder] [msgs] [−file file] [−part number] ... [−type |
content] ... [−headers | −noheaders] [−realsize | −norealsize] [−rcache policy] [−wcache policy] [−check | −nocheck] [−version] [−help]
The mhlist command allows you to list information (essentially a table of contents) about the various parts of a collection of MIME (multi-media) messages.
mhlist manipulates MIME (multi-media messages) as specified in RFC−2045 thru RFC−2049 (See mhbuild(1)).
The −headers switch indicates that a one-line banner should be displayed above the listing.
The −realsize switch tells mhlist to evaluate the “native” (decoded) format of each content prior to listing. This provides an accurate count at the expense of a small delay.
If the −verbose switch is present, then the listing will show any “extra” information that is present in the message, such as comments in the “Content-Type” header.
The option −file file directs mhlist to use the specified file as the source message, rather than a message from a folder. If you specify this file as “-”, then mhlist will accept the source message on the standard input. Note that the file, or input from standard input should be a validly formatted message, just like any other nmh message. It should NOT be in mail drop format (to convert a file in mail drop format to a folder of nmh messages, see inc(1)).
By default, mhlist will list information about the entire message (all of its parts). By using the −part and −type switches, you may limit the scope of this command to particular subparts (of a multipart content) and/or particular content types.
A part specification consists of a series of numbers separated by dots. For example, in a multipart content containing three parts, these would be named as 1, 2, and 3, respectively. If part 2 was also a multipart content containing two parts, these would be named as 2.1 and 2.2, respectively. Note that the −part switch is effective for only messages containing a multipart content. If a message has some other kind of content, or if the part is itself another multipart content, the −part switch will not prevent the content from being acted upon.
A content specification consists of a content type and a subtype. The initial list of “standard” content types and subtypes can be found in RFC−2046.
A list of commonly used contents is briefly reproduced here:
Type |
Subtypes |
|
---- |
-------- |
|
text |
plain, enriched |
|
multipart |
mixed, alternative, digest, parallel |
|
message |
rfc822, partial, external-body |
|
application |
octet-stream, postscript |
|
image |
jpeg, gif, png |
|
audio |
basic |
|
video |
mpeg |
A legal MIME message must contain a subtype specification.
To specify a content, regardless of its subtype, just use the name of the content, e.g., “audio”. To specify a specific subtype, separate the two with a slash, e.g., “audio/basic”. Note that regardless of the values given to the −type switch, a multipart content (of any subtype listed above) is always acted upon. Further note that if the −type switch is used, and it is desirable to act on a message/external-body content, then the −type switch must be used twice: once for message/external-body and once for the content externally referenced.
Checking the Contents
The −check switch tells mhlist to check each content for an integrity checksum. If a content has such a checksum (specified as a Content-MD5 header field), then mhlist will attempt to verify the integrity of the content.
$HOME/.mh_profile The user profile
Path: To determine the user’s nmh directory
Current−Folder: To find the default current folder
mhbuild(1), mhshow(1), mhstore(1), sendfiles(1)
‘+folder’ defaults to the current folder
‘msgs’ defaults to cur
‘−nocheck’
‘−headers’
‘−realsize’
‘−rcacheask’
‘−wcacheask’
‘−noverbose’
If a folder is given, it will become the current folder. The last message selected will become the current message.