A long-awaited function arrives in the production release.
PHP,
the popular Web development language, has long provided a built-in function,
mail(), to send email messages. Until recently, this function was available only
on non-System i platforms. The limitation applied both to home-grown System i
PHP versions and to beta releases of Zend Core for i5/OS (the PHP distribution
by IBM and Zend).
Users of PHP on System i can now rejoice. The GA
release of Zend Core for i5/OS, introduced in August 2006, implements
mail().
Why Is mail() Necessary?
Although alternatives such as PHPMailer provide ample features,
these substitutes take more effort to set up. More important, some software
packages are programmed to use mail() and will not operate without it.
Implementation on System i
Most UNIX systems contain a sendmail program. The
mail() function takes advantage of this by sending messages through sendmail. On
systems lacking sendmail, such as Windows and System i, Simple Mail Transfer
Protocol (SMTP) does the job.
Function Definition and Example
The mail() function takes four
parameters:
- To—Recipient's address
- Subject—Subject of the message
- Message—Message body
- Headers—Optional catch-all parameter, responsible for most
other message settings, including the sender's email address ("From:") and any
special encoding. When messages contain attachments or HTML, this parameter can
become complex.
All four parameters are shown in this short
PHP
program:
$to
=
'
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
';
$subject =
'subject of test message';
$message
= 'message body of mail() command
test';
// set “From”
header field
$headers = 'From:
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
';
// send
the message
mail($to, $subject,
$message,
$headers);
?>
Configuration
PHP.INI contains default mail settings. It can be
found at /usr/local/zend/Core/etc/php.ini.
PHP.INI has three mail
settings:
The three settings appear in PHP.INI under [mail function] like
this:
[mail
function]
SMTP=mail.myserver.com
smtp_port
= 25
sendmail_from =
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
To change these settings, either edit the INI
directly or use Zend Core's Web-based administration console.
The EDTF
(Edit File) command allows editing of PHP.INI from a command
line:
EDTF
/usr/local/zend/Core/etc/php.ini
A PC-based text editor will
also work, given adequate authority to PHP.INI.
Zend Core provides a
Web-based control panel to edit these settings, located at
http://www.domain.com:8000/ZendCore/ (where www.domain.com is the
appropriate domain name) on the PHP Configuration page (Figure 1).
Figure 1: The PHP Configuration page allows editing of sendmail_from,
SMTP, and smtp_port. (Click image to enlarge.)
Changes to PHP.INI will take effect after the
Apache server is restarted. Apache can be restarted with the Restart Server link
in the Web interface and with Zend Core's Apache menu:
GO ZENDCORE/ZCAMENU.
Set Options Dynamically with ini_set()
PHP's ini_set()
function temporarily sets a given configuration option. Ideal for altering
options dynamically, and in installations unable to change PHP.INI, ini_set()
affects options for the duration of the program that invoked it.
ini_set() takes two parameters:
- Varname—Variable/option to change
- Newvalue—Value to change to
The following lines of
code show how to set the SMTP server and "from" address within a PHP
function.
ini_set("SMTP","mail.domain.com"); //
note: “SMTP” must be upper
case.
ini_set("sendmail_from","
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");
Troubleshooting
If mail() does not work as expected, clues may be
found in PHP's error log:
/usr/local/zend/Core/logs/php_error_log
The
error log may be viewed with a text editor or this
command:
DSPF
'/usr/local/zend/Core/logs/php_error_log'
mail() vs. Alternatives
As mentioned earlier, mail() is not the only way to
send mail in PHP. Fuller-featured alternatives include the following:
• PHPMailer
• PHP Extension and Application Repository
(PEAR) Mail (recommended by the official mail() function
page for sending HTML or complex emails)
Advantages of
mail():
- It's included with PHP; no installation and little configuration
needed.
- One line of code is sufficient to send a simple message.
- Many prominent software packages, such as WordPress blog software, depend on mail(),
which is not an advantage per se, but it's a reason to have it
available.
Advantages of the alternatives:
- Support for SMTP
authentication, which is absent in mail(). In SMTP authentication, a mail client
proves its identity to an SMTP server with a user ID and password. Many SMTP
servers, such as Lotus Domino's, can be configured to demand authentication to
deter unauthorized use.
- Programmers need not understand mail headers. Complex messages and
attachments are handled easily, without complicated header
strings.
An Invaluable Tool
The mail() function works well for relatively simple
email tasks. Its hidden strength, though, is in the many software packages that
use it. With the GA release of Zend Core, System i gets the power to host an
expanded universe of commercial and open-source applications written in PHP.
Resources
• www.php.net/mail
• http://us2.php.net/manual/en/function.mail.php
• Security
Considerations for mail()
• Zend Brings
PHP to IBM's i5/OS (article by this author; introduction to PHP on System
i)
• Main page, Zend for
i5/OS
Alan Seiden is a consultant and
developer at a northern New Jersey IT firm, where he enjoys his role as a
creative software catalyst for clients. Alan is vice president of the New York City Usability Professionals
Association. Email:
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. |
