Firstly, direnv doesn't officially support alias at the moment.

Secondly,

direnv is not loading the .envrc into the current shell. It's creating a new bash sub-process to load the stdlib, direnvrc and .envrc, and only exports the environment diff back to the original shell. This allows direnv to record the environment changes accurately and also work with all sorts of shells. It also means that aliases and functions are not exportable right now.

However, envrc is simpler. It spawns a new interactive shell and load .envrc. When you cd out of the directory, the shell exits and returns terminal back to the original shell.

• cargo install envrc
• Modify the rc file of your shell.
  • For bash, add eval "$(envrc init bash)" to the end of your bashrc.
  • For zsh, add eval "$(envrc init zsh)" to the end of your zshrc.

$ mkdir foo
$ 
$ echo 'echo in foo directory' > foo/.envrc
$ 
$ cd foo
  envrc: spawning new /bin/bash
  envrc: loading [/home/roxma/test/envrc/foo/.envrc]
  in foo directory
$ 
$ cd ..
  envrc: exit [/home/roxma/test/envrc/foo/.envrc]

$ envrc
  envrc 0.2
  Rox Ma [email protected]
  auto source .envrc of your workspace

  USAGE:
      envrc [SUBCOMMAND]

  FLAGS:
      -h, --help       Prints help information
      -V, --version    Prints version information

  SUBCOMMANDS:
      init     Init the prompt command
      hook     Called for each prompt
      allow    Grant permission to envrc to load the .envrc
      deny     Remove the permission
      prune    Remove expired or non-existing-file permissions
      help     Print this message or the help of the given subcommand(s)

Note: Take care of your background jobs before getting out of .envrc.

• export WORKSPACE_DIR=$(readlink -f "$(dirname "${BASH_SOURCE[0]}")") for .envrc to locate its directory.
  • export WORKSPACE_DIR="${0:A:h}" for zsh.
• exec $SHELL to reload the modifed .envrc

# If the `.envrc` is allowed, but not sourced for 1d since last unload, It
# will be considered expired
export ENVRC_ALLOW_DURATION=$((60*60*24))
eval "$(envrc init zsh)"

The first working commit is written in python. But there's noticeable time lag with the python version on my PC. Rewriting it with perl doesn't help either. Then I decided to switch to rust.

$ time envrc.py bash-prompt-command >/dev/null
real    0m0.079s
user    0m0.044s
sys     0m0.004s

I have also tried a pure bash implementation. It works better than the python implementation, since most of the python overhead is its startup time. Most of the bash overhead is fork/exec of sub-processes and it's way slower than the rust implementation. Read #1 for more information.