This is the command mime-constructp that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
mime-construct - construct and optionally mail MIME messages
Sorry, it's hard to provide a meaningful synopsis. See the examples.
mime-construct constructs and (by default) mails MIME messages. It is entirely driven
from the command line, it is designed to be used by other programs, or people who act like
Turn debugging on.
Show the usage message and die.
Don't mail the generated message, print it to stdout instead. This loses --bcc info.
Generate a subpart which can be used in another MIME message, rather than a top-level
MIME message itself. This turns on --output and changes some internal semantics a
bit. See the examples.
Print the version and exit successfully, if this is the only arg. Otherwise, print
the version and die.
These arguments add text to the top-level header of the message, or control who it gets
Add address to the recipient list. This doesn't actually add anything to the header,
of course. If you're not actually mailing the message (if you use --output or
--subpart) --bcc will have no effect.
Add an address to the Cc: list.
Send the message to the recipients already listed in the header, in addition to those
given with --to, --cc, and --bcc. This makes sense if you use the --header switch to
add your own To: or Cc:. In this case you probably don't want to use --to or --cc
because they would create new headers rather than adding to the ones already in the
This switch passes the -t switch to sendmail (mime-construct doesn't try to parse the
headers you provide), so it doesn't really do anything if you're not mailing the
Add arbitrary text to the header. The str can be anything you like, including
multiple lines. You can create invalid messages this way. If you include a blank
line in the str you'll really screw up the message.
This specifies the multipart content type and options. The default is
"multipart/mixed". Don't include a "boundary" setting, that's supplied by mime-
It's okay if you specify the --multipart type but the message turns out to be a single
part, the type you supply will just be ignored.
This adds str to the multipart prelude text. If you specify --prelude multiple times
the strs will all be concatenated.
There isn't any default for this text. It seems to me that nowadays adding an
explanation of MIME to the beginning of a message is like explaining how to use a seat
buckle to people who are riding in an airplane.
It's okay if you specify the --prelude but the message turns out to be a single part,
the prelude you supply will just be ignored.
Specify the subject for the message.
Add an address to the To: list.
These switches control the per-part headers. If the message turns out not to be multipart
they actually add data to the top level header.
Each of these applies only to the next part output. After each part is output they are
reset to their default values. It doesn't make sense to use them without a following
part, so mime-construct will sputter and die if you try to do that.
This adds a "Content-Disposition: attachment" header with the given name as the value
of the "filename" attribute. It's just a convenience, since mime-construct is often
used to send files as attachments.
Using --attachment name does not cause mime-construct to read any data from the file
called name! It just uses that name in the header. The actual data which will go
into this part of the message comes from one of the regular part output switches
You might prefer to use the --file-attach switch, which does read from the named file.
This specifies the type of encoding you want this part to use. You normally shouldn't
use this switch, though. If this switch isn't used mime-construct will choose an
The data you supply mustn't be encoded already, mime-construct will encode it
according to the type you specify here. Valid encodings are 7bit, 8bit, binary,
quoted-printable, and base64. It's easy to generate an illegal MIME message by
specifying the encoding yourself.
Add arbitrary text to the per-part header. The str can be anything you like,
including multiple lines. You can create invalid messages this way. If you include a
blank line in the str you'll really screw up the message.
Specify the content type for this part. If you don't specify a --type it defaults to
"text/plain". The type you supply can contain not only the type proper but also
options. The whole thing will just be plopped onto the end of "Content-Type:" and
stuck into the header.
You might prefer to use the --file-auto or --file-attach switches, which set the
--type automatically based on a file's name.
These switches add data to the body of the message. You use one of these for each for
each part of a multipart message (or just one of them if the message isn't to be
Use the contents of the file path or the literal string str as the body of this part.
--file-auto causes the Content-Type to be set based on the file's name, if possible.
--file-attach does that and sets the --attachment name as well.
Be sure to include the trailing newline on str unless there really isn't supposed to
be one. If you leave the trailing newline off the part will have to be encoded in
"base64" (because "quoted-printable" has an artificial limitation which prevents it
from being able to encode such a data stream).
--attach is an alias for --file-attach, and --body is an alias for --string.
Use either the contents of path or str itself as the body of this part, but treat it
as a subpart. This means that the data contains both some headers and some text. It
also means that you can't use --type or --encoding for this part.
Normally the path or str will have been generated by a different invocation of mime-
construct which was given the --subpart switch.
Arguments to switches which take a file name (such as --file and --subpart-file) can have
some magic. If there is no file with the path supplied a regular Perl open() is done on
it. See "EXAMPLES".
The examples assume that $nl contains a newline. The other variables used are I hope
Send a simple message.
mime-construct --to "$recip" --subject 'hi there' --string "$body"
Send a message which is read from stdin.
fortune | mime-construct --to "$recip" --subject fortune --file -
Send a plain text part and attach a file, setting the file's content type and --attachment
mime-construct --to "$recip" --subject "$file" \
--string "Here's the file I told you about.$nl" \
Most people think of attachments as multipart messages, but they don't have to be. This
generates a zip of all the files in the current directory and sends them as an attachment
but as a single part message.
zip -q - * |
mime-construct --to "$recip" --subject 'zipped directory' \
--attachment dir.zip --type application/zip --file -
You can use the full expressiveness of Perl's open() when constructing file names. Eg,
you can run processes XXX bad examples, there's no file names
mime-construct --to "$recip" --subject "$subject" \
--string "Here are those two files you wanted.$nl" \
--type application/x-gzip --attachment file1.gz --file 'gzip -c file1 |' \
--type application/x-gzip --attachment file1.gz --file 'gzip -c file2 |'
or read from alternate file descriptors ("<&=4" to read from file descriptor 4) or
whatever. See perlopentut for a tutorial.
Here's an example of using a separate invocation of mime-construct to create a subpart.
This creates a message which has two parts at the top level. The first part is some text,
the second part is a digest. The digest itself is a multipart message which contains a
number of message/rfc822 parts.
for msg in $msg_list
msg_args="$msg_args --type message/rfc822 --file $msg"
for recip in $recip_list
set "$@" --bcc $recip
mime-construct --subpart --multipart multipart/digest $msg_args |
--header "To: Digest recipients:;$nl" \
--subject 'Foo digest' \
--file "$introduction" \
Here is how to send an encrypted messages (multipart/encrypted, as defined in RFC 1847).
You use mime-construct "--subpart" to generate the real message you want to send (which
can be kind of MIME message -- non-text, multi-part, what have you), then encrypt that and
use another mime-construct to contruct and send the multipart/encrypted message which
mime-construct --subpart --file body --file-auto image.jpg |
gpg --encrypt --armor -r "$recip" |
mime-construct --output \
--to "$recip" \
--subject "$subject" \
--multipart "multipart/encrypted; protocol=\"$enc_type\"" \
--type "$enc_type" \
--string "$enc_params" \
--type application/octet-stream \
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