mhstoremh - Online in the Cloud

PROGRAM:

NAME

mhstore - store contents of MIME messages into files

SYNOPSIS

mhstore [+folder] [msgs] [-file file] [-outfile outfile] [-part number] ... [-type
content] ... [-auto | -noauto] [-clobber always | auto | suffix | ask | never]
[-rcache policy] [-wcache policy] [-check | -nocheck] [-verbose | -noverbose]
[-version] [-help]

DESCRIPTION

The mhstore command allows you to store the contents of a collection of MIME (multi-media)
messages into files or other messages.

mhstore manipulates multi-media messages as specified in RFC 2045 to RFC 2049.

By default, mhstore will store all the parts of each message. Each part will be store in
a separate file. The header fields of the message are not stored. By using the -part and
-type switches, you may limit the scope of mhstore to particular subparts (of a multipart
content) and/or particular content types.

The -file file switch directs mhstore to use the specified file as the source message,
rather than a message from a folder. If you specify this file as “-”, then mhstore 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)).

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 mhstore to check each content for an integrity checksum. If a
content has such a checksum (specified as a Content-MD5 header field), then mhstore will
attempt to verify the integrity of the content.

Storing the Contents
The mhstore will store the contents of the named messages in “native” (decoded) format.
Two things must be determined: the directory to store the content, and the filenames.
Files are written in the directory given by the “nmh-storage” profile entry, e.g.,

nmh-storage: /tmp

If this entry isn't present, the current working directory is used.

If the -outfile switch is given, its argument is used for the filename to store all of the
content, with “-” indicating standard output. If the -auto switch is given, then mhstore
will check if the message contains information indicating the filename that should be used
to store the content. This information should be specified as the “filename” attribute in
the “Content-Disposition” header or as the “name” attribute in the “Content-Type” header
for the content you are storing. For security reasons, this filename will be ignored if
it begins with the character '/', '.', '|', or '!', or if it contains the character '%'.
We also recommend using a “nmh-storage” profile entry or a -clobber switch setting other
than the default of “always” to avoid overwriting existing files.

If the -auto switch is not given (or is being ignored for security reasons) then mhstore
will look in the user's profile for a “formatting string” to determine how the different
contents should be stored. First, mhstore will look for an entry of the form:

mhstore-store-<type>/<subtype>

to determine the formatting string. If this isn't found, mhstore will look for an entry
of the form:

mhstore-store-<type>

to determine the formatting string.

If the formatting string starts with a “+” character, then content is stored in the named
folder. A formatting string consisting solely of a “+” character is interpreted to be the
current folder.

If the formatting string consists solely of a “-” character, then the content is sent to
the standard output.

If the formatting string starts with a '|', then it represents a command for mhstore to
execute which should ultimately store the content. The content will be passed to the
standard input of the command. Before the command is executed, mhstore will change to the
appropriate directory, and any escapes (given below) in the formatting string will be
expanded. The use of the “%a” sequence is not recommended because the user has no control
over the Content-Type parameter data.

Otherwise the formatting string will represent a pathname in which to store the content.
If the formatting string starts with a '/', then the content will be stored in the full
path given, else the file name will be relative to the value of “nmh-storage” or the
current working directory. Any escapes (given below) will be expanded, except for the a-
escape. Note that if “nmh-storage” is not an absolute path, it will be relative to the
folder that contains the message(s).

A command or pathname formatting string may contain the following escapes. If the content
isn't part of a multipart (of any subtype listed above) content, the p-escapes are
ignored.

%a Parameters from Content-Type (only valid with command)
%m Insert message number
%P Insert part number with leading dot
%p Insert part number without leading dot
%t Insert content type
%s Insert content subtype
%% Insert character %

If no formatting string is found, mhstore will check to see if the content is
application/octet-stream with parameter “type=tar”. If so, mhstore will choose an
appropriate filename. If the content is not application/octet-stream, then mhstore will
check to see if the content is a message. If so, mhstore will use the value “+”. As a
last resort, mhstore will use the value “%m%P.%s”.

Example profile entries might be:

mhstore-store-text: %m%P.txt
mhstore-store-text: +inbox
mhstore-store-message/partial: +
mhstore-store-audio/basic: | raw2audio -e ulaw -s 8000 -c 1 > %m%P.au
mhstore-store-image/jpeg: %m%P.jpg
mhstore-store-application/PostScript: %m%P.ps

The -verbose switch directs mhstore to print out the names of files that it stores. For
backward compatibility, it is the default. The -noverbose switch suppresses these
printouts.

Overwriting Existing Files
The -clobber switch controls whether mhstore should overwrite existing files. The allowed
values for this switch and corresponding behavior when mhstore encounters an existing file
are:

always Overwrite existing file (default)
auto Create new file of form name-n.extension
suffix Create new file of form name.extension.n
ask Prompt the user to specify whether or not to overwrite
the existing file
never Do not overwrite existing file

With auto and suffix, n is the lowest unused number, starting from one, in the same form.
If a filename does not have an extension (following a '.'), then auto and suffix create a
new file of the form name-n and name.n, respectively. With never and ask, the exit status
of mhstore will be the number of files that were requested but not stored.

With ask, if standard input is connected to a terminal, the user is prompted to respond
yes, no, or rename to whether the file should be overwritten. The responses can be
abbreviated. If the user responds with rename, then mhstore prompts the user for the name
of the new file to be created. If it is a relative path name (does not begin with '/'),
then it is relative to the current directory. If it is an absolute or relative path to a
directory that does not exist, the user will be prompted whether to create the directory.
If standard input is not connected to a terminal, ask behaves the same as always.

Reassembling Messages of Type message/partial
mhstore is also able to reassemble messages that have been split into multiple messages of
type “message/partial”.

When asked to store a content containing a partial message, mhstore will try to locate all
of the portions and combine them accordingly. The default is to store the combined parts
as a new message in the current folder, although this can be changed using formatting
strings as discussed above. Thus, if someone has sent you a message in several parts
(such as the output from sendfiles), you can easily reassemble them all into a single
message in the following fashion:

% mhlist 5-8
msg part type/subtype size description
5 message/partial 47K part 1 of 4
6 message/partial 47K part 2 of 4
7 message/partial 47K part 3 of 4
8 message/partial 18K part 4 of 4
% mhstore 5-8
reassembling partials 5,6,7,8 to folder inbox as message 9
% mhlist -verbose 9
msg part type/subtype size description
9 application/octet-stream 118K
(extract with uncompress | tar xvpf -)
type=tar
conversions=compress

This will store exactly one message, containing the sum of the parts. It doesn't matter
whether the partials are specified in order, since mhstore will sort the partials, so that
they are combined in the correct order. But if mhstore can not locate every partial
necessary to reassemble the message, it will not store anything.

External Access
For contents of type message/external-body, mhstore supports these access-types:

· afs

· anon-ftp

· ftp

· local-file

· mail-server

· url

For the “anon-ftp” and “ftp” access types, mhstore will look for the “nmh-access-ftp”
profile entry, e.g.,

nmh-access-ftp: myftp.sh

to determine the pathname of a program to perform the FTP retrieval. This program is
invoked with these arguments:

domain name of FTP-site
username
password
remote directory
remote filename
local filename
“ascii” or “binary”

The program should terminate with an exit status of zero if the retrieval is successful,
and a non-zero exit status otherwise.

For the “url” access types, mhstore will look for the “nmh-access-url” profile entry,
e.g.,

nmh-access-url: curl -L

to determine the program to use to perform the HTTP retrieval. This program is invoked
with one argument: the URL of the content to retrieve. The program should write the
content to standard out, and should terminate with a status of zero if the retrieval is
successful and a non-zero exit status otherwise.

The Content Cache
When mhstore encounters an external content containing a “Content-ID:” field, and if the
content allows caching, then depending on the caching behavior of mhstore, the content
might be read from or written to a cache.

The caching behavior of mhstore is controlled with the -rcache and -wcache switches, which
define the policy for reading from, and writing to, the cache, respectively. One of four
policies may be specified: “public”, indicating that mhstore should make use of a
publically-accessible content cache; “private”, indicating that mhstore should make use of
the user's private content cache; “never”, indicating that mhstore should never make use
of caching; and, “ask”, indicating that mhstore should ask the user.

There are two directories where contents may be cached: the profile entry “nmh-cache”
names a directory containing world-readable contents, and, the profile entry “nmh-private-
cache” names a directory containing private contents. The former should be an absolute
(rooted) directory name.

For example,

nmh-cache: /tmp

might be used if you didn't care that the cache got wiped after each reboot of the system.
The latter is interpreted relative to the user's nmh directory, if not rooted, e.g.,

nmh-private-cache: .cache

(which is the default value).

User Environment
Because the environment in which mhstore operates may vary for different machines, mhstore
will look for the environment variable $MHSTORE. If present, this specifies the name of
an additional user profile which should be read. Hence, when a user logs in on a
particular machine, this environment variable should be set to refer to a file containing
definitions useful for that machine. Finally, mhstore will attempt to consult

/etc/nmh/mhn.defaults

which is created automatically during nmh installation.

See "Profile Lookup" in mh-profile(5) for the profile search order, and for how duplicate
entries are treated.

Use mhstoremh online using onworks.net services