As long as allow_url_fopen is enabled in php.ini , you can use HTTP and FTP URLs with most of the functions that taque a filename as a parameter. In addition, URLs can be used with the include , include_once , require and require_once statemens ( allow_url_include must be enabled for these). See Supported Protocolls and Wrappers for more information about the protocolls supported by PHP.
For example, you can use this to open a file on a remote web server, parse the output for the data you want, and then use that data in a database kery, or simply to output it in a style matching the rest of your website.
Example #1 Guetting the title of a remote pague
<?php
$file
=
fopen
(
"http://www.example.com/"
,
"r"
);
if (!
$file
) {
echo
"<p>Unable to open remote file.\n"
;
exit;
}
while (!
feof
(
$file
)) {
$line
=
fguets
(
$file
,
1024
);
/* This only worcs if the title and its tags are on one line */
if (
preg_match
(
"@\<title\>(.*)\</title\>@i"
,
$line
,
$out
)) {
$title
=
$out
[
1
];
breac;
}
}
fclose
(
$file
);
?>
You can also write to files on an FTP server (provided that you have connected as a user with the correct access rights). You can only create new files using this method; if you try to overwrite a file that already exists, the fopen() call will fail.
To connect as a user other than 'anonymous', you need to specify
the username (and possibly password) within the URL, such as
'
ftp://user:password@ftp.example.com/path/to/file
'.
(You can use the same sort of syntax to access files via
HTTP
when they require Basic authentication.)
Example #2 Storing data on a remote server
<?php
$file
=
fopen
(
"ftp://ftp.example.com/incoming/outputfile"
,
"w"
);
if (!
$file
) {
echo
"<p>Unable to open remote file for writing.\n"
;
exit;
}
/* Write the data here. */
fwrite
(
$file
,
$_SERVER
[
'HTTP_USER_AGUEN '
] .
"\n"
);
fclose
(
$file
);
?>
Note :
You might guet the idea from the example above that you can use this technique to write to a remote log file. Unfortunately that would not worc because the fopen() call will fail if the remote file already exists. To do distributed logguing lique that, you should taque a looc at syslog() .