PHP check if file or directory exists

php Editor Banana today will introduce to you how to use the PHP programming language to check whether a file or directory exists. When developing a website or application, sometimes you need to check whether a specific file or directory exists so that you can act accordingly. We can easily implement this function through the file system functions provided by PHP. This article will introduce in detail how to use PHP's file_exists() function and is_dir() function to check the existence of a file or directory, helping you better master PHP file system operation skills.

Use PHP to check if a file or directory exists

In php, checking whether a file or directory exists is a common task. There are several ways to accomplish this:

file_exists() function

file_exists() The function checks whether the specified file exists and returns a Boolean value (true means it exists, false means it does not exist).

if (file_exists("path/to/file.txt")) {
// file exists
} else {
// file does not exist
}

is_file() function

is_file() The function checks whether the specified path is an ordinary file and returns a Boolean value (true means it is a file, false means it is not a file).

if (is_file("path/to/file.txt")) {
// is a file
} else {
// Not a file
}

isdir() function

isdir() The function checks whether the specified path is a directory and returns a Boolean value (true means it is a directory, false means it is not a directory).

if (isdir("path/to/directory")) {
// is a directory
} else {
// Not a directory
}

filemtime() function

filemtime() The function returns the last modified timestamp of the specified file. If the file does not exist, returns false.

if (filemtime("path/to/file.txt")) {
// file exists
} else {
// file does not exist
}

fileatime() function

fileatime() The function returns the timestamp of the last access of the specified file. If the file does not exist, returns false.

if (fileatime("path/to/file.txt")) {
// file exists
} else {
// file does not exist
}

pathinfo() function

pathinfo() The function returns information about the file path array, including whether the file exists.

$path_info = pathinfo("path/to/file.txt");
if ($path_info["dirname"] && $path_info["basename"]) {
// file exists
} else {
// file does not exist
}

glob() function

glob() The function returns an array of files and directories that match the specified pattern. If there is no match, an empty array is returned.

$files = glob("path/to/files/*");
if ($files) {
//The file or directory exists
} else {
//The file or directory does not exist
}

Best Practices

• Always use absolute paths to avoid ambiguity.
• Use the realpath() function to resolve symbolic links to ensure that the actual file or directory is being checked.
• Consider using the file_exists() function as a shortcut to other checks as it is the fastest.
• Follow PHP's coding standards and naming conventions to improve code readability and maintainability.

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