来检查是否启用了它。
for（" composer install"），我会遇到错误："您的要求无法解决到可安装的软件包集。"， 谁能帮我？还试图找出我刚安装的Laravel版本吗？我遵循此网站：http：//idroot.net/linux/install-laravel-ubuntu-16-04/
~/Desktop/Project/laravel$ composer install
Cannot create cache directory /home/tanmay/.composer/cache/repo/https---packagist.org/, or directory is not writable. Proceeding without cache
Cannot create cache directory /home/tanmay/.composer/cache/files/, or directory is not writable. Proceeding without cache
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- laravel/framework v5.4.9 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.8 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.7 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.6 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.5 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.4 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.3 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.2 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.15 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.14 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.13 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.12 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.11 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.10 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.1 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- laravel/framework v5.4.0 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- Installation request for laravel/framework 5.4.* -> satisfiable by laravel/framework[v5.4.0, v5.4.1, v5.4.10, v5.4.11, v5.4.12, v5.4.13, v5.4.14, v5.4.15, v5.4.2, v5.4.3, v5.4.4, v5.4.5, v5.4.6, v5.4.7, v5.4.8, v5.4.9].
To enable extensions, verify that they are enabled in those .ini files:
- /etc/php/7.1/cli/php.ini
- /etc/php/7.1/cli/conf.d/10-opcache.ini
- /etc/php/7.1/cli/conf.d/10-pdo.ini
- /etc/php/7.1/cli/conf.d/20-calendar.ini
- /etc/php/7.1/cli/conf.d/20-ctype.ini
- /etc/php/7.1/cli/conf.d/20-exif.ini
- /etc/php/7.1/cli/conf.d/20-fileinfo.ini
- /etc/php/7.1/cli/conf.d/20-ftp.ini
- /etc/php/7.1/cli/conf.d/20-gettext.ini
- /etc/php/7.1/cli/conf.d/20-iconv.ini
- /etc/php/7.1/cli/conf.d/20-json.ini
- /etc/php/7.1/cli/conf.d/20-phar.ini
- /etc/php/7.1/cli/conf.d/20-posix.ini
- /etc/php/7.1/cli/conf.d/20-readline.ini
- /etc/php/7.1/cli/conf.d/20-shmop.ini
- /etc/php/7.1/cli/conf.d/20-sockets.ini
- /etc/php/7.1/cli/conf.d/20-sysvmsg.ini
- /etc/php/7.1/cli/conf.d/20-sysvsem.ini
- /etc/php/7.1/cli/conf.d/20-sysvshm.ini
- /etc/php/7.1/cli/conf.d/20-tokenizer.ini
尝试在终端中运行
apt-get install php7.1-mbstring
看起来像是缺少的，然后您可以通过在代码中运行phpinfo（）