composer使用笔记

一、命令

1、国内镜像

composer config -g repo.packagist composer https://packagist.phpcomposer.com

2、重新生成autoload文件

composer dump/composer dumpautoload

 

二、composer自动加载原理

composer会根据每个包的composer.json里的autoload字段来需要自动加载的类的命名空间，注册到classLoader类中。被注册的类型有psr-0/psr-4/classmap/file

 

三、问题解决

1、PHP Fatal error: Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar. This could be happening because the VPS runs out of memory and has no Swap space enabled.

free -m

total used free shared buffers cached
Mem: 2048 357 1690 0 0 237
-/+ buffers/cache: 119 1928
Swap: 0 0 0
To enable the swap you can use for example:

/bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=1024
/sbin/mkswap /var/swap.1
/sbin/swapon /var/swap.1
You can make a permanent swap file following this tutorial.