Master PHP’s glob() Function: Powerful File Pattern Matching Explained

In PHP, the glob() function is used to retrieve file paths that match a specified pattern. It returns an array of matching file paths.

Syntax

array glob ( string $pattern [, int $flags = 0 ] )

Parameters

pattern : The pattern to match. Supports wildcards *, ?, and [] where * matches zero or more characters, ? matches a single character, and [] defines a character range.

flags : Optional flags that modify matching behavior. Common flags are demonstrated in the examples below.

Examples

Match all files in a directory: $files = glob('path/to/directory/*'); This returns an array containing all files in the specified directory.

Match files with a specific extension using a wildcard: $files = glob('path/to/directory/*.txt'); This returns an array of files whose names end with .txt.

Match files using brace expansion (requires GLOB_BRACE flag):

$files = glob('path/to/directory/*.{jpg,png}', GLOB_BRACE);

This returns an array of files with .jpg or .png extensions.

Recursively match files in a directory and its sub‑directories (using ** wildcard):

$files = glob('path/to/directory/**/*', GLOB_BRACE);

This returns an array of all files under the given directory tree.

Additional uses include case‑sensitive matching, filters, and other flags. The function may return both files and directories, and if no matches are found it returns an empty array, so callers should check the result before processing.

Summary

The glob() function in PHP provides flexible and powerful file‑matching capabilities. By constructing appropriate patterns and using flags such as GLOB_BRACE, developers can efficiently locate files, handle case sensitivity, and traverse directory hierarchies, while remembering to handle empty results and differentiate files from directories.