cod

README

[[https://github.com/dim-an/cod/actions][file:https://github.com/dim-an/cod/workflows/Go/badge.svg]]

Cod is a completion daemon for ={bash,fish,zsh}=.

It detects usage of =--help= commands parses their output and generates
auto-completions for your shell.

[[https://asciinema.org/a/h0SrrNvZVcqoSM4DNyEUrGtQh][file:https://asciinema.org/a/h0SrrNvZVcqoSM4DNyEUrGtQh.svg]]

* Install
  [[https://github.com/dim-an/cod/releases][Download]] or [[#Build][build]] =cod= binary
  for your OS and put it into your =$PATH=.

  Then you need to edit your init script and add few lines.

** Bash
   Add to =~/.bashrc=
   #+BEGIN_SRC
   source <(cod init $$ bash)
   #+END_SRC

** Zsh
   Add to =~/.zshrc=
   #+BEGIN_SRC
   source <(cod init $$ zsh)
   #+END_SRC
   Or, use a plugin manager like zinit:
   #+BEGIN_SRC
   zinit wait lucid for \
     dim-an/cod
   #+END_SRC

** Fish
   Add to =~/.config/fish/config.fish=
   #+BEGIN_SRC
   cod init %self fish | source
   #+END_SRC

* Supported shells and operating systems
   =cod= is known to work with latest version of =zsh= (tested: =v5.5.1= and
   =5.7.1=) on macOS and Linux.

   =cod= also works with with latest version of =bash= (tested: =4.4.20= and
   =v5.0.11=) on Linux.

   Note that default =bash= that is bundled with macOS is too old and =cod=
   doesn't support it.

   =cod= works with latest version of =fish= (tested: =v3.1.2") on Linux
   (I didn't have a chance to test it on macOS).


* Build
  [[https://golang.org/dl/][Go v1.16]] is recommended.

  #+BEGIN_SRC
  git clone https://github.com/dim-an/cod.git
  cd cod
  go build
  #+END_SRC

  or

  #+BEGIN_SRC
  go get -u github.com/dim-an/cod
  #+END_SRC

* Overview
  Cod checks each command you run in the shell. When cod detects usage of
  =--help= flag it asks if you want it to learn this command. If you choose
  to allow cod to learn this command cod will run command itself parse the
  output and generate completions based on the =--help= output.

** How cod detects help commands
   Cod performs following checks to decide if command is help invocation:
   + checks if =--help= flag is used;
   + checks that command is simple i.e. doesn't contain any pipes, file
     descriptor redirections, and other shell magic;
   + checks that command exit code is 0.

   If cod cannot automatically detect that your command is help invocation
   you can use =learn= subcommand to learn this command anyway.

** How cod runs help commands
   Cod always uses absolute paths to run program. (So it finds binary in
   =PATH= or resolves relative path if required). Other arguments except
   binary path are left unchanged.

   Current shell environment and current shell working directory will be
   used.

   If program is successfully executed cod will store:
     - absolute path to binary;
     - used arguments;
     - working directory;
     - environment variables.
   This info will be used to update command if required (check:
   =cod help update=).

** How cod parses help output
   =cod= has generic parser that works with most of help pages and
   recognizes flags (starting with =-=) but doesn't recognize subcommands.

   It also has a special parser tuned for
   [[https://docs.python.org/library/argparse.html][python argparse library]]
   that recognizes flags and subcommands.

* Configuration
  Cod will search config in =$XDG_CONFIG_HOME/cod/config.toml= file
  (default: =~/.config/cod/config.toml=).

  Config file allows to specify rules to ignore executables or always trust
  them.

  =cod example-config= prints example configuration to stdout.
  =cod example-config --create= writes example configuration to proper config
  file.

* Data directories
  Cod uses =$XDG_DATA_HOME/cod= (default: =~/.local/share/cod=) to store all
  generated data files.