favadi / xenvflags

Automatically apply extra cli flags from environment variables

xenvflags

xenvflags is an utility that wrap around cli programs and automatically apply extra argument from environment variables. It is best used together with direnv.

Installation

# with homebrew
$ brew install favadi/xenvflags/xenvflags

# with go
$ go get github.com/favadi/xenvflags

Or download the pre-built binaries in releases section.

Example usages

For example, we are using shfmt for both personal and work projects.

• personal projects at ~/code/personal use 4 spaces indentation (arguments: -i 4)
• work projects are at ~/code/work use use 2 spaces indentation (arguments: -i 2)

The shfmt cli program is installed in /usr/local/bin/shfmt.

Setup:

• create a symlink to xenvflags: ln -s /usr/local/bin/xenvflags $HOME/bin/shfmt
• append SHFMT_EXTRA_ARGS='-i 4' to ~/code/personal/.envrc
• append SHFMT_EXTRA_ARGS='-i 2' to ~/code/work/.envrc

With direnv hook enabled, running shfmt in personal and work projects will have the desired indentation flags append.

Debug

# print xenvflags version and exit
$ XENVFLAGS_VERSION=true shfmt
dev

# print debug information
$ SHFMT_EXTRA_ARGS="-i 2" XENVFLAGS_DEBUG=true shfmt --help
2022/10/23 16:40:36 version: dev
2022/10/23 16:40:36 executable: /usr/local/bin/shfmt
2022/10/23 16:40:36 original arguments: [--help]
2022/10/23 16:40:36 extra arguments from env: [-i 2]
...