Working With Files In PHP

Here are some basic functions we can use when working with files in PHP.

I. List all files and directories

We can use the function scandir() to list all files and directories of a specific path.

Syntax

scandir(directory, order)

order:

We can specify the sorting order. The default sort order is ascending order (0).

SCANDIR_SORT_DESCENDING or 1 to sort in alphabetical descending order.
SCANDIR_SORT_NONE to return the result unsorted.

Example

$dir = scandir(__DIR__);
var_dump($dir);
// array(4) { [0]=> string(1) "." [1]=> string(2) ".." [2]=> string(9) ".DS_Store" [3]=> string(9) "index.php" }

II. Check if it’s a file or directory

We can check whether a specific filename is a file or a directory using is_file() or is_dir().

Syntax

// Check if it's a file
is_file(file)
// Check if it's a directory
is_dir(file)

Example

$dir = scandir(__DIR__);

var_dump(is_file($dir[2])); // bool(true)
var_dump(is_dir($dir[2])); // bool(false)

III. Check if file or directory exists

We can check if a file or a directory exists using the file_exists() function. This function’s result is cached.

Syntax

file_exists(path)

Example

if (file_exists("text.txt")) {
    echo filesize("text.txt");
} else {
    echo "File not found";
} // File not found

IV. Clear cache

PHP cache the return value of some file-related functions for better performance.

Affected functions: stat(), lstat(), file_exists(), is_writable(), is_readable(), is_executable(), is_file(), is_dir(), is_link(), filectime(), fileatime(), filemtime(), fileinode(), filegroup(), fileowner(), filesize(), filetype(), and fileperms().

We can use clearstatcache() to clear the cache.

Syntax

clearstatcache()

V. Create a directory

We can create a new directory using the mkdir() function.

Syntax

mkdir(path);

Example

mkdir("partials");

VI. Delete a directory

We can delete a directory using the rmdir() function.

Syntax

rmdir(dir)

Example

rmdir("partials");

VII. Open file

We can open a file using the fopen() function.

Syntax

fopen(filename, mode)

There are several modes for fopen .

“r”: Read only.
“r+”: Read/Write.
“w”: Write only. Opens file or creates a new file if it doesn’t exist.

Example

$file = fopen("text.txt", "r");

VIII. Close a file

Syntax

We use the fclose() function to close an open file.

fclose(file)

Example

$file = fopen("text.txt", "r");
fclose($file);

IX. feof()

We can check if the “end-of-file” is reached for an open file usingfeof().

It’s useful in loops.

X. Read file line by line

We can use the fgets() function to return a line from an open file.

Syntax

fgets(file)

Example

$file = fopen("text.txt","r");

while(! feof($file)) {
  echo fgets($file). "<br>";
}

fclose($file);

XI. Read CSV files

The fgetcsv() function parses a line from an open file and returns an array.

Syntax

fgetcsv(file, length, separator)

Example

$file = fopen("text.txt","r");

while(! feof($file)) {
  echo "<pre>";
  print_r(fgetcsv($file));
  echo "</pre>";
}

fclose($file);

/* Array
(
    [0] => a
    [1] => b
    [2] => c
)
Array
(
    [0] => d
    [1] => e
    [2] => f
)
Array
(
    [0] => g
    [1] => h
    [2] => i
) */

XII. Get file content

We can read file content using the file_get_contents() function.

Syntax

file_get_contents(path, include_path, start, max_length)

Example

echo file_get_contents("text.txt", offset: 2, length: 3);
// llo

XIII. Write content to a file

We can write content to a file using the file_put_contents() function.

Syntax

file_put_contents(filename, data, mode, )

Example

echo file_put_contents("text.txt","Testing!");

XIV. Delete, copy, rename files

To delete a file, we use the function unlink().
To copy a file, we use the function copy(). If the to_fine file already exists, it will be overwritten.
To rename a file, we use the function rename().

Syntax

unlink(filename)
copy(from_file, to_file)
rename(old, new)

Example

unlink("text.txt");
echo copy("from.txt","to.txt");
rename("/partials/file1.txt","/docs/file2.txt");

XV. Check path info

We can check information about a file path using the pathinfo() function.

Syntax

pathinfo(path, options)

Option values

PATHINFO_DIRNAME: return only dirname.
PATHINFO_BASENAME: return only basename.
PATHINFO_EXTENSION: return only extension.
PATHINFO_FILENAME: return only filename.

Example

print_r(pathinfo("/docs/text.txt"));