eat-emacs/integration/bash

# integration/bash --- Bash integration

# Copyright (C) 2022 Akib Azmain Turja.

# This file is not part of GNU Emacs.

# This file is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# For a full copy of the GNU General Public License
# see <https://www.gnu.org/licenses/>.

__eat_prompt_command () {
  # Send the current working directory, for directory tracking.
  printf '\e]7;file://%s%s\e\\' "$HOSTNAME" "$PWD"
}

__eat_preexec () {
  # "${PWD/$HOME/'~'}" converts "/home/akib/org/" to "~/org/".
  # The next one is substituted with '$', or '#' if we're "root".
  printf '\e]2;%s@%s:%s%s %s\e\\' "$USER" "$HOSTNAME" \
         "${PWD/$HOME/'~'}" \
         "$(test $UID -eq 0 && echo '#' || echo '$')" "$BASH_COMMAND"
}

__eat_in_prompt_command=no

__eat_before_prompt_command ()
{
  __eat_in_prompt_command=yes
}

__eat_after_prompt_command ()
{
  __eat_in_prompt_command=no
}

__eat_before_exec () {
  if test $__eat_in_prompt_command = no \
      && test "$BASH_COMMAND" != __eat_before_prompt_command
  then
    __eat_preexec
  fi
}

# Add '__eat_prompt_command' as the last element of 'PROMPT_COMMAND'.
if test -z "$__eat_bash_integration_enabled"
then
  __eat_bash_integration_enabled=yes
  PS1='\[\e]2;\u@\h:\w$\e\\\]'"$PS1"
  PROMPT_COMMAND+=(__eat_prompt_command)
  trap '__eat_before_exec' DEBUG
  # Wrap 'PROMPT_COMMAND' to avoid it getting trapped in 'DEBUG' trap.
  # Step 1: Append to PROMPT_COMMAND.
  PROMPT_COMMAND+=(__eat_after_prompt_command)
  # Step 2: Prepend to PROMPT_COMMAND.
  # Step 2.1: Move all elements to make the first index free.
  # Fun fact: Microsoft doesn't still know this simple trick.  They
  # use something as silly and pityful as 'VAR=$PROMPT_COMMAND' to
  # copy a Bash array in VSCode Bash integration script, that simply
  # won't work ever, and then complain about Bash in the comments!
  # LOL.  ;D
  for i in $(eval "printf {${#PROMPT_COMMAND[*]}..1..-1}")
  do
    PROMPT_COMMAND[$i]=${PROMPT_COMMAND[$((i-1))]}
  done
  # Step 2.2: Assign the first element.
  PROMPT_COMMAND[0]=__eat_before_prompt_command
fi

# Local Variables:
# mode: sh
# End: