$ brew install php71 ==> Installing php71 from homebrew/php Error: Cannot install homebrew/php/php71 because conflicting formulae are installed. php56: because different php versions install the same binaries. Please `brew unlink php56` before continuing. Unlinking removes a formula's symlinks from /usr/local. You can link the formula again after the install finishes. You can --force this install,
![MacOSXでbrew install phpをVersion7.1へ - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/6b93fc990cbfcac939834568c33d3c9a54a21a65/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-9f5428127621718a910c8b63951390ad.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTkxNiZoPTMzNiZ0eHQ9TWFjT1NYJUUzJTgxJUE3YnJldyUyMGluc3RhbGwlMjBwaHAlRTMlODIlOTJWZXJzaW9uNy4xJUUzJTgxJUI4JnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9NTYmdHh0LWNsaXA9ZWxsaXBzaXMmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz0xZWYxNzg4YmU5MzgzZjVhZDc2MzZhMWQzMjA0YmYzZA%26mark-x%3D142%26mark-y%3D112%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTYxNiZ0eHQ9JTQwYm9oZWJvaGVjaGFuJnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz05NTY1ZWNiY2FmMGVlZWZjZDU0NTE0NDZlZjc3YTI5NQ%26blend-x%3D142%26blend-y%3D491%26blend-mode%3Dnormal%26s%3Dfb696654c80d11921cce95486a2d3b7e)