php_uname

Returns information about the operating system PHP is running on

&reftitle.description; `string` `php_uname` `string` `mode`"a"

`php_uname` returns a description of the operating system PHP is running on. This is the same string you see at the very top of the `phpinfo` output. For the name of just the operating system, consider using the `PHP_OS` constant, but keep in mind this constant will contain the operating system PHP was built on.

On some older UNIX platforms, it may not be able to determine the current OS information in which case it will revert to displaying the OS PHP was built on. This will only happen if your uname() library call either doesn't exist or doesn't work.

&reftitle.parameters;

`mode`

- `mode` is a single character that defines what information is returned:

  - `'a'`: This is the default. Contains all modes in the sequence `"s n r v m"`.

  - `'s'`: Operating system name. eg. `FreeBSD`.

  - `'n'`: Host name. eg. `localhost.example.com`.

  - `'r'`: Release name. eg. `5.1.2-RELEASE`.

  - `'v'`: Version information. Varies a lot between operating systems.

  - `'m'`: Machine type. eg. `i386`.

&reftitle.returnvalues;

Returns the description, as a string.

&reftitle.examples;

### Some `php_uname` examples

    <?php
    echo php_uname();
    echo PHP_OS;

    /* Some possible outputs:
    Linux localhost 2.4.21-0.13mdk #1 Fri Mar 14 15:08:06 EST 2003 i686
    Linux

    FreeBSD localhost 3.2-RELEASE #15: Mon Dec 17 08:46:02 GMT 2001
    FreeBSD

    Windows NT XN1 5.1 build 2600
    WINNT
    */

    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        echo 'This is a server using Windows!';
    } else {
        echo 'This is a server not using Windows!';
    }

    ?>

There are also some related Predefined PHP constants that may come in handy, for example:

### A few OS related constant examples

    <?php
    // *nix
    echo DIRECTORY_SEPARATOR; // /
    echo PHP_SHLIB_SUFFIX;    // so
    echo PATH_SEPARATOR;      // :

    // Win*
    echo DIRECTORY_SEPARATOR; // \
    echo PHP_SHLIB_SUFFIX;    // dll
    echo PATH_SEPARATOR;      // ;
    ?>

&reftitle.seealso;

- `phpversion`
- `php_sapi_name`
- `phpinfo`