brew update

Fetch the newest version of Homebrew and all formulae


-f, --forceAlways do a slower, full update check
-v, --verbosePrint the directories checked and git operations performed
-d, --debugDisplay a trace of all shell commands as they are executed
-h, --helpShow help message
--mergeUse git merge to apply updates (rather than git rebase)
--preinstallRun on auto-updates (e.g. before brew install). Skips some slower steps