MIME-CONSTRUCT(1p) User Contributed Perl Documentation MIME-CONSTRUCT(1p)
NAME
mime-construct - construct and optionally mail MIME messages
SYNOPSIS
mime-construct switch...
Sorry, it's hard to provide a meaningful synopsis. See the examples.
DESCRIPTION
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 programs.
OPTIONS
Global Settings
--debug
Turn debugging on.
--help
Show the usage message and die.
--output
Don't mail the generated message, print it to stdout instead. This
loses --bcc info.
--subpart
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.
--version
Print the version and exit successfully, if this is the only arg.
Otherwise, print the version and die.
Main Header
These arguments add text to the top-level header of the message, or
control who it gets sent to.
--bcc address
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.
--cc address
Add an address to the Cc: list.
--embedded-to
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 message.
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 message.
--header str
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.
--multipart str
This specifies the multipart content type and options. The default
is "multipart/mixed". Don't include a "boundary" setting, that's
supplied by mime-construct.
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.
--prelude str
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.
--subject str
Specify the subject for the message.
--to address
Add an address to the To: list.
Per-part Header
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.
--attachment name
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 (given
below).
You might prefer to use the --file-attach switch, which does read
from the named file.
--encoding type
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 appropriate encoding.
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.
--part-header str
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.
--type type
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.
Part Output
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 multipart).
--file path
--file-auto path
--file-attach path
--attach path
--string str
--body str
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.
--subpart-file path
--subpart-string str
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".
EXAMPLES
The examples assume that $nl contains a newline. The other variables
used are I hope self-explanatory.
Send a simple message.
mime-construct --to "$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 name automatically.
mime-construct --to "$recip" --subject "$file" \
--string "Here's the file I told you about.$nl" \
--file-attach "$file"
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.
msg_args=
for msg in $msg_list
do
msg_args="$msg_args --type message/rfc822 --file $msg"
done
set fnord
for recip in $recip_list
do
set "$@" --bcc $recip
done
shift
mime-construct --subpart --multipart multipart/digest $msg_args |
mime-construct \
--header "To: Digest recipients:;$nl" \
--subject 'Foo digest' \
"$@" \
--file "$introduction" \
--subpart-file -
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 construct and send the multipart/encrypted message
which contains it.
enc_type=application/pgp-encrypted
enc_params="Version: 1$nl"
mime-construct --subpart --file body --file-auto image.jpg |
gpg --encrypt --armor -r "$recip" |
mime-construct --output \
--to "$recip" \
--subject "$subject" \
--multipart "multipart/encrypted; protocol=\"$enc_type\"" \
--type "$enc_type" \
--string "$enc_params" \
--type application/octet-stream \
--file -
BUGS
The body of the message is always held in memory, so you can expect
problems if you work with bodies which are large compared to the amount
of memory you've got.
AVAILABILITY
The code is licensed under the GNU GPL. Check
http://www.argon.org/~roderick/ for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.36.0 2023-01-06 MIME-CONSTRUCT(1p)
Generated by dwww version 1.15 on Thu Sep 4 15:21:32 CEST 2025.