Saturday, September 29, 2012

PHP_EOL: Most Worthless Constant?

PHP_EOL may very well be the most worthless general-purpose constant in modern PHP. It's supposed to be helpful for cross-platform developing, for example you could write a PHP-powered shell script that says:

<?php
echo "Operation Successful!" . PHP_EOL;

and then expect the proper newline to terminate the output string based on the platform PHP is running on.

That's all well and good, but the following is functionally equivalent:

<?php
echo "Operation Successful!\n";

Try it out and you'll see. In console output on Windows, Linux, and Mac they all are displayed with the expect newline terminating the output string.

I don't see it being useful for writing data or log output to a file either. If you're writing and reading on the same platform then newline discrepancies won't be an issue, and if you're writing on one platform and reading on another then you'll want to standardize on a newline anyway.

Has PHP_EOL's time come and gone? Do you use it in your code, and if so why?

7 comments:

  1. Your thoughts on using \n than PHP_EOL doesn't sounds good for me. The \n has a problem, for it will not be a new line if its quoted inside single quotes. So the expected behavior differs ;).

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    Replies
    1. Thanks for the comment! Yeah people do seem to hate double quotes, don't they.

      One could use the inverse argument with PHP_EOL, though: it MUST be appended. With \n you can either embed it in a double-quoted string or append it, whichever you prefer. Not only is it less typing, it's more flexible.

      echo "Operation Successful!\n";
      echo 'Operation Successful!' . "\n";

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  2. I never noticed \n produced a newline on windows PHP shell scripts.. always been using PHP_EOL for those.

    One actual use-case I could think of might be if you're for example generating text files. Considering Windows' default offerings for text editors (notepad) screw up *nix newlines completely, it might be a good idea to use PHP_EOL in a case like that.

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  3. I agree with you, I think is totally useless now. I've never used it and probably I'll never do.

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  4. you're forgetting that when writing files it will produce different results.
    Not to mention if you commit those files to git and you are with a group of unix developers... not fun.

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  5. Just to note, if you use double quotes, php will analyze de string in search for things to interpret (like \n or variables), if you use single quotes php will just pass the string. There for, if you don't need to put variables or commands inside a string, use single quotes, then concat the eol. Everything depends on the use and preference. For me is better to use single quotes to "save" a little bit of processing and then append PHP_EOL avoiding passing the string trhough the php parser before.

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  6. It's useful if generating files that are meant to be compatible with other platforms. A good example is writing a framework or object that generates cache files, system log files, inserts text database records, or sends emails (some mail servers expect the platform's EOL). If you upload your linux specific "\n" script to a windows or mac based distro you have the potential of messing things up. Similar issues with DIRECTORY_SEPARATOR and PATH_SEPARATOR. If you're writing scripts that are not going to be migrating cross-platform, then it is useless, but if you're writing shared class objects or a framework, you will eventually get bug reports related to the newline being statically defined.

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