Add brew shellenv - see #4780

Library/Homebrew/cmd/shellenv.rb

@@ -0,0 +1,16 @@
+#:  * `shellenv`:
+#:    Prints export statements - run them in a shell and this installation of
+#:    Homebrew will be included into your PATH, MANPATH, and INFOPATH.
+#:    Tip: have your dotfiles eval the output of this command
+
+module Homebrew
+  module_function
+
+  def shellenv
+    puts <<~EOS
+      export PATH="#{HOMEBREW_PREFIX}/bin:#{HOMEBREW_PREFIX}/sbin:$PATH"
+      export MANPATH="#{HOMEBREW_PREFIX}/share/man:$MANPATH"
+      export INFOPATH="#{HOMEBREW_PREFIX}/share/info:$INFOPATH"
+    EOS
+  end
+end

Library/Homebrew/test/cmd/shellenv_spec.rb

@@ -0,0 +1,8 @@
+describe "brew shellenv", :integration_test do
+  it "doesn't fail" do
+    expect { brew "shellenv" }
+      .to output(%r{#{HOMEBREW_PREFIX}/bin}).to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
+  end
+end

docs/Manpage.md

@@ -441,6 +441,11 @@ With `--verbose` or `-v`, many commands print extra debugging information. Note
 
     If `--env=std` is passed, use the standard `PATH` instead of superenv's.
 
+  * `shellenv`:
+    Prints export statements - run them in a shell and this installation of
+    Homebrew will be included into your PATH, MANPATH, and INFOPATH.
+    Tip: have your dotfiles eval the output of this command
+
   * `style` [`--fix`] [`--display-cop-names`] [`--only-cops=``cops`|`--except-cops=``cops`] [`files`|`taps`|`formulae`]:
     Check formulae or files for conformance to Homebrew style guidelines.
 

manpages/brew.1

@@ -404,6 +404,9 @@ If \fB\-\-desc\fR is passed, search formulae with a description matching \fItext
 If \fB\-\-env=std\fR is passed, use the standard \fBPATH\fR instead of superenv\'s\.
 .
 .IP "\(bu" 4
+\fBshellenv\fR: Prints export statements \- run them in a shell and this installation of Homebrew will be included into your PATH, MANPATH, and INFOPATH\. Tip: have your dotfiles eval the output of this command
+.
+.IP "\(bu" 4
 \fBstyle\fR [\fB\-\-fix\fR] [\fB\-\-display\-cop\-names\fR] [\fB\-\-only\-cops=\fR\fIcops\fR|\fB\-\-except\-cops=\fR\fIcops\fR] [\fIfiles\fR|\fItaps\fR|\fIformulae\fR]: Check formulae or files for conformance to Homebrew style guidelines\.
 .
 .IP