Merge pull request #201 from gregory-nisbet/feature-env-shells

--env: support more shells, allow explicit shell selection

1 files changed, 87 insertions, 0 deletions

diff --git a/Library/Homebrew/utils/shell.rb b/Library/Homebrew/utils/shell.rb
new file mode 100644
index 000000000..c0d6b90ae
--- /dev/null
+++ b/Library/Homebrew/utils/shell.rb
@@ -0,0 +1,87 @@
+module Utils
+  SHELL_PROFILE_MAP = {
+    :bash => "~/.bash_profile",
+    :csh => "~/.cshrc",
+    :fish => "~/.config/fish/config.fish",
+    :ksh => "~/.kshrc",
+    :sh => "~/.bash_profile",
+    :tcsh => "~/.tcshrc",
+    :zsh => "~/.zshrc",
+  }.freeze
+
+  module Shell
+    UNSAFE_SHELL_CHAR = /([^A-Za-z0-9_\-.,:\/@\n])/
+
+    # take a path and heuristically convert it
+    # to a shell name, return nil if there's no match
+    def self.path_to_shell(path)
+      # we only care about the basename
+      shell_name = File.basename(path)
+      # handle possible version suffix like `zsh-5.2`
+      shell_name.sub!(/-.*\z/m, "")
+      shell_name.to_sym if %w[bash csh fish ksh sh tcsh zsh].include?(shell_name)
+    end
+
+    def self.preferred_shell
+      path_to_shell(ENV.fetch("SHELL", ""))
+    end
+
+    def self.parent_shell
+      path_to_shell(`ps -p #{Process.ppid} -o ucomm=`.strip)
+    end
+
+    def self.csh_quote(str)
+      # ruby's implementation of shell_escape
+      str = str.to_s
+      return "''" if str.empty?
+      str = str.dup
+      # anything that isn't a known safe character is padded
+      str.gsub!(UNSAFE_SHELL_CHAR, "\\\\" + "\\1")
+      # newlines have to be specially quoted in csh
+      str.gsub!(/\n/, "'\\\n'")
+      str
+    end
+    
+    def self.sh_quote(str)
+      # ruby's implementation of shell_escape
+      str = str.to_s
+      return "''" if str.empty?
+      str = str.dup
+      # anything that isn't a known safe character is padded
+      str.gsub!(UNSAFE_SHELL_CHAR, "\\\\" + "\\1")
+      str.gsub!(/\n/, "'\n'")
+      str
+    end
+
+    # quote values. quoting keys is overkill
+    def self.export_value(shell, key, value)
+      case shell
+      when :bash, :ksh, :sh, :zsh
+        "export #{key}=\"#{sh_quote(value)}\""
+      when :fish
+        # fish quoting is mostly Bourne compatible except that
+        # a single quote can be included in a single-quoted string via \'
+        # and a literal \ can be included via \\
+        "set -gx #{key} \"#{sh_quote(value)}\""
+      when :csh, :tcsh
+        "setenv #{key} #{csh_quote(value)};"
+      end
+    end
+
+    # return the shell profile file based on users' preferred shell
+    def self.shell_profile
+      SHELL_PROFILE_MAP.fetch(preferred_shell, "~/.bash_profile")
+    end
+
+    def self.prepend_path_in_shell_profile(path)
+      case preferred_shell 
+      when :bash, :ksh, :sh, :zsh, nil
+        "echo 'export PATH=\"#{sh_quote(path)}:$PATH\"' >> #{shell_profile}"
+      when :csh, :tcsh
+        "echo 'setenv PATH #{csh_quote(path)}:$PATH' >> #{shell_profile}"
+      when :fish
+        "echo 'set -g fish_user_paths \"#{sh_quote(path)}\" $fish_user_paths' >> #{shell_profile}"
+      end
+    end
+  end
+end