From a3a3e3b878e46e1f1c1e1225cc9588daa14e5c93 Mon Sep 17 00:00:00 2001 From: Mike McQuaid Date: Sat, 16 Feb 2019 09:46:57 +0000 Subject: [PATCH] Formula Cookbook: env var docs tweaks. --- docs/Formula-Cookbook.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/docs/Formula-Cookbook.md b/docs/Formula-Cookbook.md index 52612c1408..8a6a2b22ea 100644 --- a/docs/Formula-Cookbook.md +++ b/docs/Formula-Cookbook.md @@ -1,6 +1,6 @@ # Formula Cookbook -A *formula* is a package definition written in Ruby. It can be created with `brew create ` where `` is a zip or tarball, installed with `brew install `, and debugged with `brew install --debug --verbose `. Formulae use the [Formula API](https://www.rubydoc.info/github/Homebrew/brew/master/Formula) which provides various Homebrew-specific helpers. +A *formula* is a package definition written in Ruby. It can be created with `brew create ` where `` is a zip or tarball, installed with `brew install `, and debugged with `brew install --drefebug --verbose `. Formulae use the [Formula API](https://www.rubydoc.info/github/Homebrew/brew/master/Formula) which provides various Homebrew-specific helpers. ## Homebrew terminology @@ -700,9 +700,9 @@ Homebrew provides two formula DSL methods for launchd plist files: Homebrew has multiple levels of environment variable filtering which affects variables available to formulae. -Firstly, the overall environment in which Homebrew runs is filtered to avoid environment contamination breaking from-source builds ([ref](https://github.com/Homebrew/brew/issues/932)). In particular, this process filters all but the given whitelisted variables, but allows environment variables prefixed with `HOMEBREW_`. The specific implementation can be seen in the [`brew`](https://github.com/Homebrew/brew/blob/master/bin/brew) script. +Firstly, the overall environment in which Homebrew runs is filtered to avoid environment contamination breaking from-source builds (https://github.com/Homebrew/brew/issues/932). In particular, this process filters all but the given whitelisted variables, but allows environment variables prefixed with `HOMEBREW_`. The specific implementation can be seen in [`bin/brew`](https://github.com/Homebrew/brew/blob/master/bin/brew). -The second level of filtering removes sensitive environment variables (such as credentials like keys, passwords or tokens) to avoid malicious subprocesses obtaining them ([ref](https://github.com/Homebrew/brew/pull/2524)). This has the effect of preventing any such variables from reaching a formula's Ruby code as they are filtered before it is called. The specific implementation can be seen in the [`clear_sensitive_environment` method](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/ENV.rb). +The second level of filtering removes sensitive environment variables (such as credentials like keys, passwords or tokens) to avoid malicious subprocesses obtaining them (https://github.com/Homebrew/brew/pull/2524). This has the effect of preventing any such variables from reaching a formula's Ruby code as they are filtered before it is called. The specific implementation can be seen in the [`ENV.clear_sensitive_environment!` method](https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/ENV.rb). In summary, environment variables used by a formula need to conform to these filtering rules in order to be available.