Allow php_uname to be disabled, fixes composer/getcomposer.org#112

src/Composer/Console/Application.php

@@ -159,7 +159,7 @@ class Application extends BaseApplication
                 Composer::VERSION,
                 Composer::RELEASE_DATE,
                 defined('HHVM_VERSION') ? 'HHVM '.HHVM_VERSION : 'PHP '.PHP_VERSION,
-                php_uname('s') . ' / ' . php_uname('r')
+                function_exists('php_uname') ? php_uname('s') . ' / ' . php_uname('r') : 'Unknown OS'
             ), true, IOInterface::DEBUG);
 
             if (PHP_VERSION_ID < 50302) {

src/Composer/Util/StreamContextFactory.php

@@ -143,8 +143,8 @@ final class StreamContextFactory
             $options['http']['header'][] = sprintf(
                 'User-Agent: Composer/%s (%s; %s; %s%s)',
                 Composer::VERSION === '@package_version@' ? 'source' : Composer::VERSION,
-                php_uname('s'),
-                php_uname('r'),
+                function_exists('php_uname') ? php_uname('s') : 'Unknown',
+                function_exists('php_uname') ? php_uname('r') : 'Unknown',
                 $phpVersion,
                 getenv('CI') ? '; CI' : ''
             );