cgiemail, cgiecho, cgifile - CGI Form-to-Mail conversion tools
The cgiemail user guide
This guide will help you write a WWW form that sends an e-mail message
to you. The following steps are required:
· Create an e-mail template.
· Put a link to the template on your page.
· Decide if a mailto: link will do.
· Create the HTML form.
· Create more advanced HTML forms.
· Make sure the ACTION is correct.
· Try out your form with cgiecho.
· Go live with cgiemail.
· Debug if you don’t get mail
The following steps are optional.
· Add text to the success page.
· Use an alternate success page.
· Make some inputs required.
· Specify formatting for some inputs.
· Use CGI environment variables.
Create an e-mail template.
Before you start receiving e-mail messages through the web, you should
decide what these messages should look like. Create an ASCII file,
called an e-mail template, that looks something like this:
To: firstname.lastname@example.org HEADER LINES
Subject: questions three
What is your name? [yourname]
What is your quest? [quest] BODY
What is your favourite colour? [colour]
In one sense, this template is free-form. People who want to send you
e-mail can download this template, fill it out, and mail it to you.
However, the template will also be used by the cgiemail program, so
before you upload the file to your WWW server, be careful to follow
· Wherever you want the user of your form to supply information, use
a single word inside square brackets with no spaces, e.g. Your
name: [yourname]. Not [Put your name here].
· Make sure the address in the To: field is correct.
· If there are blank lines among the header lines, remove them.
· If there are blank lines before the header lines, remove them.
· Make sure all your header lines are valid. The first character on
the line must be a letter. Most information should go in the
message body; don’t make up your own headers.
· Make sure there is a blank line between the header lines and the
· Make sure you save it as ASCII text. For example, if you are using
Microsoft Word, use "Save As" and choose "Text Only with Line
· If you created the file on a Mac, be sure to upload it as text,
i.e. CR’s translated. (Unix computers have different codes denoting
the end of a line than Mac’s do, so your file might look like one
long line to the Unix computer.)
Within these guidelines there is a lot of flexibility. You can put
Bcc:, X-Face:, or any other header in the headers. You can put things
like Cc: [yourname] in the headers. Be creative. Just don’t put
anything in there you wouldn’t want your webmaster to see, because
that’s where bounced messages go.
Now go ahead and upload your e-mail template to the WWW server and look
at it with your WWW browser.
Put a link to the template on your page.
Here’s an example:
Would you like to cross the bridge? Download my "questions three" form
and send it to <email@example.com>.
Even after you create your WWW form, you will want to leave this link
in to increase accessibility to users with disabilities.
Decide if a mailto: link will do.
Already, without any complicated HTML, you have a way for people on the
WWW to send you the information you want. Before you go to the effort
of making an HTML form, decide if it’s really worth it. Forms on the
WWW have two particular disadvantages:
· You will get a lot of frivolous e-mail from people who are merely
‘‘surfing the web.’’
· The user’s e-mail address is typed manually, and is often mistyped,
so that you have no way to reply. This is less of a problem with
Create the HTML form.
If you’ve decided to create an HTML form, you need to give people a way
to supply an e-mail address. With the mailto: link, their mailer would
supply the From: address for them. But now you need to add a line to
the top of your e-mail template like this:
Here is an example HTML form.
Your e-mail address: ____________________
Your name: ____________________
Your quest: ____________________
Your favourite colour: ____________________
Send e-mail (This example doesn't actually send e-mail.)
This is the HTML source:
Your e-mail address: <INPUT NAME="email"><p>
Your name: <INPUT NAME="yourname"><p>
Your quest: <INPUT NAME="quest"><p>
Your favourite colour: <INPUT NAME="colour"><p>
<INPUT TYPE="submit" value="Send e-mail">
This is a very simple example. Note that the NAME of each input
corresponds to what you previously put in the e-mail template. In this
example they are email, yourname, quest, and colour. This is the key
concept in using cgiemail. Be careful to make them exactly the same; if
you put NAME="colour" in your HTML form and [color] (note the spelling
difference) in your e-mail template, the input will not show up in the
Create more advanced HTML forms.
To learn to create more complicated forms, read NCSA’s guide. All of
their example forms can be converted to cgiemail forms merely by
changing the ACTION. Unlike other forms-to-email programs, you are not
required to use hidden inputs with special names.
All types of inputs (radio buttons, etc.) work the same way. Each input
needs a NAME, and that name must appear within square brackets in your
e-mail template. It’s that simple. To get more ideas, see the cgiemail
Make sure the ACTION is correct.
The trickiest part of the HTML form is getting the ACTION set
correctly. Start with the URL of your e-mail template, then split it
into two parts, e.g.
\ /\ /
`--- Part 1 ---' ` -------- Part 2 ----------'
Then you put the script name in the middle. Usually this is
‘‘/cgi-bin/cgiecho’’, but it depends on how your server is configured.
On web.mit.edu it happens to be ‘‘/bin/cgiecho’’, thus my ACTION looks
\ /\ /\ /
`--- Part 1 ---' script name ` -------- Part 2 ----------'
For simplicity, you may leave out part 1, but you must include it if
you want to test your form as a local file. If you don’t know what that
means, just feel free to omit part 1.
Try out your form with cgiecho.
Pop your form into your favorite WWW browser, fill in the inputs, and
submit it. You should see what the processed form looks like. If
instead you see an error with a number near 500, your ACTION is
probably set wrong. Go back to the previous step.
If some of your inputs don’t seem to be showing up in the processed
form, make sure that the inputs have the exact same names in the HTML
form as in the ASCII template. E.g. NAME="yourname" in the HTML form
and [yourname] in the e-mail template.
Go live with cgiemail.
Now change cgiecho to cgiemail in the ACTION of your HTML form. Try it
out. You should receive an e-mail message with the processed form. If
you get a success page but don’t receive mail, there is some problem
with your template file. Go back and make sure you correctly followed
the guidelines in step 1.
If it works, congratulations!
9. Debug if you don’t get mail
Normally, mail gets sent asynchronously, meaning it goes into a queue
to be sent at at a convenient time. Asynchronous mail is sent more
efficiently and reliably, but has the disadvantage that problems can
only be reported by mailing an error message back to the sender. To the
mail system, it appears that the sender of the mail is the web server,
so the error message won’t get to you.
If you aren’t getting mail, you can temporarily use synchronous mail
delivery by creating a hidden input named cgiemail-mailopt and giving
it a value containing "sync", e.g.
<INPUT TYPE="hidden" NAME="cgiemail-mailopt" VALUE="sync">
Note: For release 1.1, this won’t work. Ask your webmaster to install a
newer release. Some mailers have a nonstandard extension that sends
bounces to an address in an Errors-To: header in addition to the web
server. However, some errors make this header line unreadable, so
there’s no way to make absolutely sure the bounce will go to you.
Optional: Add text to the success page.
When mail is sent, a page titled ‘‘Success’’ appears with the text of
the e-mail message. You may use a hidden variable called ‘‘addendum’’
to add your own text. Here is a simple example:
<INPUT TYPE="hidden" NAME="addendum" VALUE="Thank you!">
If you are willing to assume that readers of your form are using recent
browser software like Lynx 2.6 or Netscape 3.0, then you may put HTML
markup into this variable using the appropriate character entities. For
example, if you wanted to add
then the HTML markup would be
meaning you would need the following in your form:
<INPUT TYPE="hidden" NAME="addendum"
Note that besides being difficult to write, this feature won’t work for
people using older browser software.
Optional: Use an alternate success page.
If you don’t like the default page that comes up when email is
successfully sent, you can specify an alternate URL using a hidden
variable called ‘‘success’’ in your HTML form, e.g.
<INPUT TYPE="hidden" NAME="success" VALUE="http://web.mit.edu/">
Note: Start your URL with / or with http://. Otherwise cgiemail will
direct your browser to a second invocation of cgiemail, resulting in
the error No variable substitutions.
As of release 1.3, there is no way to make this alternate success page
contain information the user submitted in the form. This feature is
likely to be added in a future release.
Optional: Make some inputs required.
If you would like to automatically reject forms with certain inputs
left blank, add the prefix ‘‘required-’’ to the name of the input in
both your HTML form and your e-mail template. Here is an example:
In the HTML form:
Your name: <INPUT NAME="required-yourname">
In the e-mail template
Your name: [required-yourname]
Optional: Specify formatting for some inputs.
If, in your e-mail template, the text inside square brackets begins
with %, cgiemail will use the printf() function in C on the field name
after the comma. If you’re not familiar with this function, look in a
book on C. If you are familiar with it, please note these two
· The first character in the format string must be %.
· Characters like \n and \t must be literal. If you want a newline,
you have to put a newline just before the comma, even though this
looks strange. For example, if Godzilla’s Pizza wanted toppings
listed one per line, they would put the following in their e-mail
Optional: Use CGI environment variables.
This feature may or may not work, depending on whether or not your
webmaster enabled it when configuring cgiemail.
In addition to form inputs, your e-mail template can include CGI
environment variables simply by preceding the variable’s name with a
dollar sign. For example,
will put the name of the user’s browser and/or gateway in your e-mail
message. In order to be respectful of privacy, your HTML form should
warn users about any information about them that will be included in
the e-mail, e.g. HTTP_USER_AGENT, REMOTE_ADDR.
Upstream contact: cgiemail <firstname.lastname@example.org>
Debian maintainer: Anibal Monsalve Salazar
Complete information on building, installing and using cgiemail is
available on the WWW: