$ brew info icu4c
brew info icu4c
icu4c: stable 60.2 (bottled), HEAD [keg-only]
C/C++ and Java libraries for Unicode and globalization
http://site.icu-project.org/
/usr/local/Cellar/icu4c/58.2 (242 files, 65MB)
Poured from bottle on 2017-10-13 at 13:02:42
/usr/local/Cellar/icu4c/60.2 (249 files, 67MB)
Poured from bottle on 2018-03-02 at 13:51:28
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/icu4c.rb
==> Options
--HEAD
Install HEAD version
==> Caveats
This formula is keg-only, which means it was not symlinked into /usr/local,
because macOS provides libicucore.dylib (but nothing else).
If you need to have this software first in your PATH run:
echo 'export PATH="/usr/local/opt/icu4c/bin:$PATH"' >> ~/.zshrc
echo 'export PATH="/usr/local/opt/icu4c/sbin:$PATH"' >> ~/.zshrc
For compilers to find this software you may need to set:
LDFLAGS: -L/usr/local/opt/icu4c/lib
CPPFLAGS: -I/usr/local/opt/icu4c/include
For pkg-config to find this software you may need to set:
PKG_CONFIG_PATH: /usr/local/opt/icu4c/lib/pkgconfig
$ brew switch icu4c 58.2
$ php -v
PHP 5.6.31 (cli) (built: Oct 16 2017 12:08:02)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
with Xdebug v2.5.5, Copyright (c) 2002-2017, by Derick Rethans