Writing a new line to file in PHP (line feed)

Question

My code:

$i = 0;
$file = fopen('ids.txt', 'w');
foreach ($gemList as $gem)
{
    fwrite($file, $gem->getAttribute('id') . '\n');
    $gemIDs[$i] = $gem->getAttribute('id');
    $i++;
}
fclose($file);

For some reason, it's writing \n as a string, so the file looks like this:

40119\n40122\n40120\n42155\n36925\n45881\n42145\n45880

From Google'ing it tells me to use \r\n, but \r is a carriage return which doesn't seem to be what I want to do. I just want the file to look like this:

40119
40122
40120
42155
36925
45881
42145
45880

Thanks.

Solution 1

Replace '\n' with "\n". The escape sequence is not recognized when you use '.

See the manual.

For the question of how to write line endings, see the note here. Basically, different operating systems have different conventions for line endings. Windows uses "\r\n", unix based operating systems use "\n". You should stick to one convention (I'd chose "\n") and open your file in binary mode (fopen should get "wb", not "w").

Solution 2

PHP_EOL is a predefined constant in PHP since PHP 4.3.10 and PHP 5.0.2. See the manual posting:

Using this will save you extra coding on cross platform developments.

IE.

$data = 'some data'.PHP_EOL;
$fp = fopen('somefile', 'a');
fwrite($fp, $data);

If you looped through this twice you would see in 'somefile':

some data
some data

Solution 3

Use PHP_EOL which outputs \r\n or \n depending on the OS.

Solution 4

You can also use file_put_contents():

file_put_contents('ids.txt', implode("\n", $gemList) . "\n", FILE_APPEND);

View more solutions

Comments

[Alix Axel]

Don't get in trouble, always use \n unless you want to open the file in a specific OS - if so, use the newline combination of that OS, and not the OS you're running PHP on (PHP_EOL).

[csonuryilmaz]

I have changed "\r\n" to "\n" for my line ending amd it worked. Thanks.

[Mr PizzaGuy]

now my code uses both " and ' and it bothers me

[DarkVeneno]

In fact, you can actually notice that \n gets highlighted when using "" but not when using ' '. (This is, if your editor uses syntax highlighting, mine is Sublime Text 3)

[Sami Haroon]

This is the best answer. more dynamic, and handles fopen(), fwrite(), fclose() by itself.

[Christian]

That's good for few writes, but when you want to do a lot of writes (i.e. in a loop) you may consider fopen/fwrite/fclose for performance reasons. grobmeier.solutions/…

[cachius]

Might perform better when the file is on a ramdisk.