direnv_stdlib(1) the .envrc stdlib


direnv stdlib


Outputs a bash script called the stdlib. The following commands are included in that script and loaded in the context of an ".envrc". In addition, it also loads the file in "~/.direnvrc" if it exists.


  • has command: Returns 0 if the command is available. Returns 1 otherwise. It can be a binary in the PATH or a shell function.


if has curl; then
  echo "Yes we do"
  • expand_path rel_path [relative_to]: Outputs the absolute path of rel_path relative to relative_to or the current directory.


cd /usr/local/games
expand_path ../foo
# output: /usr/local/foo
  • dotenv [dotenv_path]: Loads a ".env" file into the current environment
  • user_rel_path abs_path: Transforms an absolute path abs_path into a user-relative path if possible.


echo $HOME
# output: /home/user
user_rel_path /home/user/my/project
# output: ~/my/project
user_rel_path /usr/local/lib
# output: /usr/local/lib
  • find_up filename: Outputs the path of filename when searched from the current directory up to /. Returns 1 if the file has not been found.


cd /usr/local/my
mkdir -p project/foo
touch bar
cd project/foo
find_up bar
# output: /usr/local/my/bar
  • source_env fileordir_path: Loads another ".envrc" either by specifying its path or filename.
  • source_up [filename]: Loads another ".envrc" if found with the find_up command.
  • direnv_load [command-generating-dump-output] Applies the environment generated by running argv as a command. This is useful for adopting the environment of a child process - cause that process to run "direnv dump" and then wrap the results with direnv_load.


direnv_load opam-env exec -- direnv dump
  • PATH_add path: Prepends the expanded path to the PATH environment variable. It prevents a common mistake where PATH is replaced by only the new path.


# output: /home/user/my/project
PATH_add bin
echo $PATH
# output: /home/user/my/project/bin:/usr/bin:/bin
  • path_add varname path: Works like PATH_add except that it's for an arbitrary varname.
  • load_prefix prefix_path: Expands some common path variables for the given prefix_path prefix. This is useful if you installed something in the prefix_path using ./configure --prefix=$prefix_path && make install and want to use it in the project.

Variables set:



./configure --prefix=$HOME/rubies/ruby-1.9.3
make && make install
# Then in the .envrc
load_prefix ~/rubies/ruby-1.9.3
  • layout type: A semantic dispatch used to describe common project layouts.
  • layout go: Sets the GOPATH environment variable to the current directory.
  • layout node: Adds "$PWD/node_modules/.bin" to the PATH environment variable.
  • layout perl: Setup environment variables required by perl's local::lib See <http://search.cpan.org/dist/local-lib/lib/local/lib.pm> for more details
  • layout python [python_exe]: Creates and loads a virtualenv environment under $PWD/.direnv/python-$python_version. This forces the installation of any egg into the project's sub-folder.

It's possible to specify the python executable if you want to use different versions of python (eg: layout python python3).

Note that previously virtualenv was located under $PWD/.direnv/virtualenv and will be re-used by direnv if it exists.

  • layout python3: A shortcut for layout python python3
  • layout ruby: Sets the GEMHOME environment variable to `$PWD/.direnv/ruby/RUBYVERSION. This forces the installation of any gems into the project's sub-folder. If you're using bundler it will create wrapper programs that can be invoked directly instead of using thebundle exec` prefix.
  • use program_name [version]: A semantic command dispatch intended for loading external dependencies into the environment.


use_ruby() {
  echo "Ruby $1"
use ruby 1.9.3
# output: Ruby 1.9.3
  • use rbenv: Loads rbenv which add the ruby wrappers available on the PATH.
  • use nix [...]: Load environment variables from nix-shell.

If you have a default.nix or shell.nix these will be used by default, but you can also specify packages directly (e.g use nix -p ocaml).

See <http://nixos.org/nix/manual/#sec-nix-shell>

  • rvm ...: Should work just like in the shell if you have rvm installed.


Copyright (C) 2014 zimbatm <http://zimbatm.com> and contributors under the MIT licence.