What is glob() in php?

To read all the files in a particular directory using PHP, we can use glob() function. This function allows to read any (pathname) file/ sub directory/ both in a particular directory (in which files are being searched).

Table of Contents Show

Definition:
Description
How to use glob() function
Examples of glob() function by patterns
Examples of glob() function by flags
Searching/ pathnames (files and folders in a paricular sub folder)
What is a glob function?
What is glob search?
What are glob files?
Is glob built in?

Definition:

The glob() function returns an array of filenames or directories matching a specified pattern(given pattern as first argument). The glob() function returns an array containing the matched files/directories names, an empty array if no file/directory is matched and FALSE if any error occurs.

Syntax of glob() function (as on official website)

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

Description

glob() function uses two parameters. First is mandatory string pattern and second is optional integer (flag).

How to use glob() function

First parameter is a string which is treated as pattern to search pathnames (files/directories).

Using above two folders for search

Examples of glob() function by patterns

Eg-1: To search any file or directory

$search_results=glob('*');

print_r($search_results);

/*output

Array

(

[0] => folder-one

[1] => folder-two

[2] => index.php

[3] => php-file-one.php

[4] => php-file-two.php

[5] => techbriefers-file.txt

[6] => techbriefers-folder

[7] => test-file-one.txt

[8] => test-file-two.txt

)

Eg-2: To search only PHP files

$search_results=glob('*.php');

print_r($search_results);

/*output

Array

(

[0] => index.php

[1] => php-file-one.php

[2] => php-file-two.php

)

Eg-3: To search only text files

$search_results=glob('*.txt');

print_r($search_results);

/*output

Array

(

[0] => techbriefers-file.txt

[1] => test-file-one.txt

[2] => test-file-two.txt

)

Eg-4: To search any file or directory starts with ‘a’

$search_results=glob('a*');

print_r($search_results);

/*output

Array

(

)

Eg-4: To search any file or directory starts with ‘tech’

$search_results=glob('tech*');

print_r($search_results);

/*output

Array

(

[0] => techbriefers-file.txt

[1] => techbriefers-folder

)

Eg-5: To search any file or directory contains ‘brie’

$search_results=glob('*brie*');

print_r($search_results);

/*output

Array

(

[0] => techbriefers-file.txt

[1] => techbriefers-folder

)

Eg-6: To search any file or directory that starts with ‘tech’ and end with ‘folder’

$search_results=glob('tech*folder');

print_r($search_results);

/*output

Array

(

[1] => techbriefers-folder

)

Second parameter is an integer which should be a valid flag.

Valid flags:

GLOB_MARK – Adds a slash to the end each directory name found

GLOB_NOSORT – Return files as they appear in the directory without sorting alphabetically. When this flag is not used, the pathnames are sorted alphabetically

GLOB_NOCHECK – Return the search pattern if no files matching it were found

GLOB_NOESCAPE – Backslashes do not quote metacharacters

GLOB_BRACE – Expands {a,b,c} to match ‘a’, ‘b’, or ‘c’

GLOB_ONLYDIR – Return only directory entries which match the pattern

GLOB_ERR – Stop on read errors (like unreadable directories), by default errors are ignored.

Examples of glob() function by flags

Eg-7: To add slash at the end of directory

$search_results=glob('*',GLOB_MARK);

print_r($search_results);

/*output

Array

(

[0] => folder-one/

[1] => folder-two/

[2] => index.php

[3] => php-file-one.php

[4] => php-file-two.php

[5] => techbriefers-file.txt

[6] => techbriefers-folder/

[7] => test-file-one.txt

[8] => test-file-two.txt

)

Eg-8: To see unsorted list of files and directories

$search_results=glob('*',GLOB_NOSORT);

print_r($search_results);

/*output

Array

(

[0] => test-file-one.txt

[1] => index.php

[2] => techbriefers-file.txt

[3] => php-file-one.php

[4] => php-file-two.php

[5] => test-file-two.txt

[6] => folder-two

[7] => folder-one

[8] => techbriefers-folder

)

Eg-9: If file/folder is not found returns pattern, without using GLOB_NOCHECK returns an empty array

$search_results=glob('new*',GLOB_NOCHECK);

print_r($search_results);

/*output

Array

(

[0] => new*

)

Clear difference can bee seen if you compare Eg-9 and Eg-4. In Eg-4 results are not found hence empty array is returned.

Eg-10: To search only directories (other files are ignored in search)

$search_results=glob('*',GLOB_ONLYDIR);

print_r($search_results);

/*output

Array

(

[0] => folder-one

[1] => folder-two

[2] => techbriefers-folder

)

Searching/ pathnames (files and folders in a paricular sub folder)

Eg-11: To search files and folders in ‘techbriefers-folder’ directory

$search_results=glob('techbriefers-folder/*');

print_r($search_results);

/*output

Array

(

[0] => techbriefers-folder/sub-file-one.txt

[1] => techbriefers-folder/sub-file-two.txt

[2] => techbriefers-folder/sub-folder-one

[3] => techbriefers-folder/sub-folder-two

)

***I have used echo ‘<pre>’; before printing array to show in a user friendly view.

What is a glob function?

glob (short for global) is used to return all file paths that match a specific pattern. We can use glob to search for a specific file pattern, or perhaps more usefully, search for files where the filename matches a certain pattern by using wildcard characters.

What is glob search?

The glob() function searches for all the pathnames matching pattern according to the rules used by the libc glob() function, which is similar to the rules used by common shells.

What are glob files?

A glob is a term used to define patterns for matching file and directory names based on wildcards. Globbing is the act of defining one or more glob patterns, and yielding files from either inclusive or exclusive matches.

Is glob built in?

With glob, we can also use wildcards ("*, ?, [ranges]) apart from exact string search to make path retrieval more simple and convenient. Note: This module comes built-in with Python, so there is no need to install it externally.