(PHP >= 5.3.0, PECL fileinfo >= 0.1.0)
finfo_open -- finfo::__construct — Create a new fileinfo resource
过程化风格
$options = FILEINFO_NONE
[, string $magic_file = NULL
]] )面向对象风格 (constructor):
$options = FILEINFO_NONE
[, string $magic_file = NULL
]] )This function opens a magic database and returns its resource.
options
One or disjunction of more Fileinfo constants.
magic_file
Name of a magic database file, usually something like /path/to/magic.mime. If not specified, the MAGIC environment variable is used. If the environment variable isn't set, then PHP's bundled magic database will be used.
Passing NULL or an empty string will be equivalent to the default
value.
(Procedural style only)
Returns a magic database resource on success 或者在失败时返回 FALSE.
The expected magic database format changed in PHP 5.3.11 and 5.4.1. Due to this, the internal magic database was upgraded. This mostly effects code where an external magic database is used: reading an older magic file will now fail. Also, some textual representations of the mime types has changed, for instance for PHP would be "PHP script, ASCII text" instead of "PHP script text" returned.
Note:
Generally, using the bundled magic database (by leaving
magic_fileand the MAGIC environment variables unset) is the best course of action unless you specifically need a custom magic database.
Example #1 面向对象风格
<?php
$finfo = new finfo(FILEINFO_MIME, "/usr/share/misc/magic"); // return mime type ala mimetype extension
/* get mime-type for a specific file */
$filename = "/usr/local/something.txt";
echo $finfo->file($filename);
?>
Example #2 过程化风格
<?php
$finfo = finfo_open(FILEINFO_MIME, "/usr/share/misc/magic"); // return mime type ala mimetype extension
if (!$finfo) {
echo "Opening fileinfo database failed";
exit();
}
/* get mime-type for a specific file */
$filename = "/usr/local/something.txt";
echo finfo_file($finfo, $filename);
/* close connection */
finfo_close($finfo);
?>
以上例程会输出：
text/plain; charset=us-ascii