step1、install Xcode

step2、install xcpkg

step3、update xcpkg-formula-repository

xcpkg update

step4、build and install m4

xcpkg install m4

xcpkg formula view m4

{{ formula }}

if the formula of m4 dosn't meet your needs, you can edit it ⤵︎

xcpkg formula edit m4

after editing, you may want to rebuild this package ⤵︎

xcpkg install m4