What does file () do in php?

(PHP 4, PHP 5, PHP 7, PHP 8)

file — Reads entire file into an array

Description

file(string $filename, int $flags = 0, ?resource $context = null): array|false

Note:

You can use file_get_contents() to return the contents of a file as a string.

Parameters

Path to the file.

Tip

A URL can be used as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename. See the Supported Protocols and Wrappers for links to information about what abilities the various wrappers have, notes on their usage, and information on any predefined variables they may provide.

The optional parameter flags can be one, or more, of the following constants:

A context stream resource.

Return Values

Returns the file in an array. Each element of the array corresponds to a line in the file, with the newline still attached. Upon failure, file() returns false.

Note:

Each line in the resulting array will include the line ending, unless FILE_IGNORE_NEW_LINES is used.

Note: If PHP is not properly recognizing the line endings when reading files either on or created by a Macintosh computer, enabling the auto_detect_line_endings run-time configuration option may help resolve the problem.

Errors/Exceptions

Emits an E_WARNING level error if the file does not exist.

Examples

Example #1 file() example

// Get a file into an array.  In this example we'll go through HTTP to get
// the HTML source of a URL.
$lines = file('http://www.example.com/');// Loop through our array, show HTML source as HTML source; and line numbers too.
foreach ($lines as $line_num => $line) {
    echo "Line #{$line_num} : " . htmlspecialchars($line) . "\n";
}// Using the optional flags parameter
$trimmed = file('somefile.txt', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
?>

Notes

Warning

When using SSL, Microsoft IIS will violate the protocol by closing the connection without sending a close_notify indicator. PHP will report this as "SSL: Fatal Protocol Error" when you reach the end of the data. To work around this, the value of error_reporting should be lowered to a level that does not include warnings. PHP can detect buggy IIS server software when you open the stream using the https:// wrapper and will suppress the warning. When using fsockopen() to create an ssl:// socket, the developer is responsible for detecting and suppressing this warning.

See Also

• file_get_contents() - Reads entire file into a string
• readfile() - Outputs a file
• fopen() - Opens file or URL
• fsockopen() - Open Internet or Unix domain socket connection
• popen() - Opens process file pointer
• include - include
• stream_context_create() - Creates a stream context

Martin K. ¶

8 years ago

If the file you are reading is in CSV format do not use file(), use fgetcsv().  file() will split the file by each newline that it finds, even newlines that appear within a field (i.e. within quotations).

bingo at dingo dot com ¶

8 years ago

To write all the lines of the file in other words to read the file line by line you can write the code like this:
$names=file('name.txt');
// To check the number of lines
echo count($names).'
';
foreach($names as $name)
{
   echo $name.'
';
}
?>

this example is so basic to understand how it's working. I hope it will help many beginners.

Regards,
Bingo

renanlazarotto at gmail dot com ¶

1 year ago

Be aware that using file() to count lines can cause OOM on the server as it'll allocate all lines into an array.

If you're dealing with files that can have thousands of lines, SplFileObject might be a better idea and with little changes you can get the same result.

d basin ¶

12 years ago

this may be obvious, but it took me a while to figure out what I was doing wrong. So I wanted to share. I have a file on my "c:\" drive. How do I file() it?

Don't forget the backslash is special and you have to "escape" the backslash i.e. "\\":

$lines

twichi at web dot de ¶

11 years ago

read from CSV data (file) into an array with named keys

... with or without 1st row = header (keys)
(see 4th parameter of function call as  true / false)

// --------------------------------------------------------------function csv_in_array($url,$delm=";",$encl="\"",$head=false) { $csvxrow = file($url);   // ---- csv rows to array ----$csvxrow[0] = chop($csvxrow[0]);
    $csvxrow[0] = str_replace($encl,'',$csvxrow[0]);
    $keydata = explode($delm,$csvxrow[0]);
    $keynumb = count($keydata);

        if (

\r\n"; 
print_r($csvdata);
echo "

sheldon at hyperlinked dot com ¶

3 years ago

As of PHP 5.6 the file(), file_get_contents(), and fopen() functions will return false if you are referencing a source URL that doesn't have a valid SSL certificate. Presumably, you will run into this a lot in your development environments this will drive you crazy.

You will need to create a stream context and provide it as an argument to the various file operations to tell it to ignore invalid SSL credentials.

$args = array("ssl"=>array("verify_peer"=>false,"verify_peer_name"=>false),"http"=>array('timeout' => 60, 'user_agent' => 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.9) Gecko/20071025 Firefox/3.0.0.1'));

$context = stream_context_create($args);
$httpfile = file($url, false, $context);

justin at visunet dot ie ¶

19 years ago

Note: Now that file() is binary safe it is 'much' slower than it used to be. If you are planning to read large files it may be worth your while using fgets() instead of file() For example:

$fd = fopen ("log_file.txt", "r");
while (!feof ($fd))
{
   $buffer = fgets($fd, 4096);
   $lines[] = $buffer;
}
fclose ($fd);
?>

The resulting array is $lines.

I did a test on a 200,000 line file. It took seconds with fgets()  compared to minutes with file().

Reversed: moc dot liamg at senroc dot werdna ¶

15 years ago

This note applies to PHP 5.1.6 under Windows (although may apply to other versions).

It appears that the 'FILE_IGNORE_NEW_LINES' flag doesn't remove newlines properly when reading Windows-style text files, i.e. files whose lines end in '\r\n'.

Solution: Always use 'rtrim()' in preference to 'FILE_IGNORE_NEW_LINES'.

Anonymous ¶

8 years ago

("file()'s problem with UTF-16" is wrong. This is updated.
The former may miss the last line of the string.)

file() seems to have a problem in handling
UTF-16 with or without BOM.

file() is likely to think "\n"=LF (0A) as a line-ending.
So, not only "000A" but also "010A, 020A,...,FE0A, FF0A,..."
are regarded as line-endings.

Moreover, file() causes a serious problem in UTF-16LE.
file() loses first "0A" (the first half of "0A00")!
And the next line begins with "00" (the rest of "0A00").
So lines after the first "0A" are totally different.

To avoid this phenomena,
eg. in case (php_script : UTF-8 , file : UTF-16 with line-ending "\r\n"),

mb_regex_encoding

vbchris at gmail dot com ¶

14 years ago

If you're getting "failed to open stream: Permission denied" when trying to use either file() or fopen() to access files on another server. Check your host doesn't have any firewall restrictions in-place which prevent outbound connections. This is the case with my host Aplus.net

jon+spamcheck at phpsitesolutions dot com ¶

14 years ago

A user suggested using rtrim always, due to the line ending conflict with files that have an EOL that differs from the server EOL.

Using rtrim with it's default character replacement is a bad solution though, as it removes all whitespace in addition to the '\r' and '\n' characters.

A good solution using rtrim follows:

$line = rtrim($line, "\r\n") . PHP_EOL;
?>

This removes only EOL characters, and replaces with the server's EOL character, thus making preg_* work fine when matching the EOL ($)

lanresmith ¶

5 years ago

Using if ( file(name.txt) ) might not be enough for testing if the file was successfully opened for reading because the file could be empty in which case the array returned is empty, so test instead with !==. e.g.:

$file_array = file('test.txt'); // an empty file

echo '

';
if ( $file_array ) {
    # code...
    echo "success\n";
} else {
    # code...
    echo "failure\n"; // executed
}
if ( $file_array !== false ) {
    # code...
    echo "success\n"; // executed
} else {
    # code...
    echo "failure\n";
}
echo '

result:
failure
success

marco dot remy at aol dot com ¶

8 years ago

Here's my CSV converter
supports Header and trims all fields
Note: Headers must be not empty!

function csv2array($file, $delim = ';', $encl = '"', $header = false) {# File does not exist
    if(!file_exists($file))
        return false;# Read lines of file to array
    $file_lines = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);# Empty file
    if($file_lines === array())
        return NULL;# Read headers if you want to
    if($header === true) {
        $line_header = array_shift($file_lines);
        $array_header = array_map('trim', str_getcsv($line_header, $delim, $encl));
    }$out = NULL;# Now line per line (strings)
    foreach ($file_lines as $line) {
        # Skip empty lines
        if(trim($line) === '')
            continue;# Convert line to array
        $array_fields = array_map('trim', str_getcsv($line, $delim, $encl));# If header present, combine header and fields as key => value
        if($header === true)
            $out[] = array_combine ($array_header, $array_fields);
        else
            $out[] = $array_fields;
    }

        return

info at carstanje dot com ¶

15 years ago

Using file() for reading large text files > 10 Mb gives problems, therefore you should use this instead. It is much slower but it works fine. $lines will return an array with all the lines.

$handle = @fopen('yourfile...', "r");
if ($handle) {
   while (!feof($handle)) {
       $lines[] = fgets($handle, 4096);
   }
   fclose($handle);
}
?>