composer更新时遇到的几个问题

在使用composer安装时，提示

Warning: This development build of composer is over 60 days old. It is recommended to update it by running “/usr/bin/composer self-update” to get the latest version.

接着按提示运行 /usr/bin/composer self-update 依然无效。正确的命令为 composer selfupdate

运行后依然有错误提示

[ErrorException]
zlib_decode(): data error

修改php.ini中

zlib.output_compression = On
zlib.output_compression_level = 5

然后再运行：composer selfupdate 问题解决