PHP作曲家安装给出错误“?? +?”

I'm getting the following output when trying to install PHP composer. Any ideas about what's wrong?

[user temp]$ curl -s https://getcomposer.org/installer | php -d detect_unicode=Off -d suhosin.executor.include.whitelist=phar
Some settings on your machine may cause stability issues with Composer.
If you encounter issues, try to change the following:

PHP was compiled with --with-curlwrappers which will cause issues with HTTP authentication and GitHub.
Recompile it without this flag if possible

Downloading...

Composer successfully installed to: /home/user/temp/composer.phar
Use it: php composer.phar

[user temp]$ php composer.phar install
??+?[user temp]$ 

Fixed the problem, it was a permissions problem! It doesn't work within Jailshell.