Master PHP’s file() Function: Read Files into Arrays with Flags

In PHP there are many convenient functions for file operations, and the file function is commonly used to read a file’s contents and return them as an array.

Function prototype

array file ( string $filename [, int $flags = 0 [, resource $context ]] )

To demonstrate, create a text file sample.txt with several lines:

Hello, world!
This is a sample file.
It is used for testing file functions in PHP.

Reading the file with the default settings:

$fileContent = file("sample.txt");
print_r($fileContent);

The output shows each line as an array element, including the newline characters:

Array
(
    [0] => Hello, world!
    [1] => This is a sample file.
    [2] => It is used for testing file functions in PHP.
)

By default the newline at the end of each line is retained. To omit newlines, use the FILE_IGNORE_NEW_LINES flag:

$fileContent = file("sample.txt", FILE_IGNORE_NEW_LINES);
print_r($fileContent);

The resulting array no longer contains the newline characters.

You can also combine flags, for example to skip empty lines as well:

$fileContent = file("sample.txt", FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
print_r($fileContent);

This call removes both the newline characters and any empty lines, leaving only the non‑empty lines in the array.

In summary, the PHP file function provides a simple way to read a file into an array, with optional flags to control newline retention and empty‑line skipping, giving flexible file‑handling capabilities.