Definition and usage of is_file() function in PHP

The is_file() function in php is used to determine whether the file exists. The method of use is also very simple. Friends in need can refer to it.

is_file() function checks whether the specified file name is a normal file.

is_file — Tells whether the filename is a regular file

Usage:
bool is_file (string $filename) $file is a required parameter
If the file exists and is normal file returns TRUE.

Let’s take a look at Example 1 first:

<?php
var_dump(is_file(&#39;a_file.txt&#39;)) . "\n";
var_dump(is_file(&#39;/usr/bin/&#39;)) . "\n";
?>

The above example will output:
bool(true)
bool(false)

Example 2:

<?php
function isfile($file){
return preg_match(&#39;/^[^.^:^?^-][^:^?]*.(?i)&#39; . getexts() . &#39;$/&#39;,$file);
//first character cannot be . : ? - subsequent characters can&#39;t be a : ?
//then a . character and must end with one of your extentions
//getexts() can be replaced with your extentions pattern
}
function getexts(){
//list acceptable file extensions here
return &#39;(app|avi|doc|docx|exe|ico|mid|midi|mov|mp3|
mpg|mpeg|pdf|psd|qt|ra|ram|rm|rtf|txt|wav|word|xls)&#39;;
}
echo isfile(&#39;/Users/YourUserName/Sites/index.html&#39;);
?>

Example 3:

<?php
function deletefolder($path)
{
if ($handle=opendir($path))
{
while (false!==($file=readdir($handle)))
{
if ($file<>"." AND $file<>"..")
{
if (is_file($path.&#39;/&#39;.$file))
{
@unlink($path.&#39;/&#39;.$file);
}
if (is_dir($path.&#39;/&#39;.$file))
{
deletefolder($path.&#39;/&#39;.$file);
@rmdir($path.&#39;/&#39;.$file);
}
}
}
}
}
?>

This function will delete all files and folders.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

Related recommendations:

php method for recursive operations on directories and file names

php Chinese font And string operation to implement Chinese verification code

php combines regular expressions to obtain the numbers in the string.

The above is the detailed content of Definition and usage of is_file() function in PHP. For more information, please follow other related articles on the PHP Chinese website!