shell-integration.sh

# shellcheck shell=bash

# This file hooks up shell integration for wezterm.
# It is suitable for zsh and bash.
#
# Although wezterm is mentioned here, the sequences used are not wezterm
# specific and may provide the same functionality for other terminals.  Most
# terminals are good at ignoring OSC sequences that they don't understand, but
# if not there are some bypasses:
#
# WEZTERM_SHELL_SKIP_ALL - disables all
# WEZTERM_SHELL_SKIP_SEMANTIC_ZONES - disables zones
# WEZTERM_SHELL_SKIP_CWD - disables OSC 7 cwd setting
# WEZTERM_SHELL_SKIP_USER_VARS - disable user vars that capture information
#                                about running programs

# shellcheck disable=SC2166
if [ -z "${BASH_VERSION}" -a -z "${ZSH_NAME}" ]; then
	# Only for bash or zsh
	return 0
fi

if [ "${WEZTERM_SHELL_SKIP_ALL}" = "1" ]; then
	return 0
fi

if [[ $- != *i* ]]; then
	# Shell integration is only useful in interactive sessions
	return 0
fi

case "$TERM" in
linux | dumb)
	# Avoid terminals that don't like OSC sequences
	return 0
	;;
esac

# This function wraps bash-preexec.sh so that it can be included verbatim
# in this file, even though it uses `return` to short-circuit in some cases.
__wezterm_install_bash_prexec() {

	# bash-preexec.sh -- Bash support for ZSH-like 'preexec' and 'precmd' functions.
	# https://github.com/rcaloras/bash-preexec
	#
	#
	# 'preexec' functions are executed before each interactive command is
	# executed, with the interactive command as its argument. The 'precmd'
	# function is executed before each prompt is displayed.
	#
	# Author: Ryan Caloras (ryan@bashhub.com)
	# Forked from Original Author: Glyph Lefkowitz
	#
	# V0.5.0
	#

	# General Usage:
	#
	#  1. Source this file at the end of your bash profile so as not to interfere
	#     with anything else that's using PROMPT_COMMAND.
	#
	#  2. Add any precmd or preexec functions by appending them to their arrays:
	#       e.g.
	#       precmd_functions+=(my_precmd_function)
	#       precmd_functions+=(some_other_precmd_function)
	#
	#       preexec_functions+=(my_preexec_function)
	#
	#  3. Consider changing anything using the DEBUG trap or PROMPT_COMMAND
	#     to use preexec and precmd instead. Preexisting usages will be
	#     preserved, but doing so manually may be less surprising.
	#
	#  Note: This module requires two Bash features which you must not otherwise be
	#  using: the "DEBUG" trap, and the "PROMPT_COMMAND" variable. If you override
	#  either of these after bash-preexec has been installed it will most likely break.

	# Tell shellcheck what kind of file this is.
	# shellcheck shell=bash

	# Make sure this is bash that's running and return otherwise.
	# Use POSIX syntax for this line:
	if [ -z "${BASH_VERSION-}" ]; then
		return 1
	fi

	# We only support Bash 3.1+.
	# Note: BASH_VERSINFO is first available in Bash-2.0.
	if [[ -z "${BASH_VERSINFO-}" ]] || ((BASH_VERSINFO[0] < 3 || (BASH_VERSINFO[0] == 3 && BASH_VERSINFO[1] < 1))); then
		return 1
	fi

	# Avoid duplicate inclusion
	if [[ -n "${bash_preexec_imported:-}" ]]; then
		return 0
	fi
	bash_preexec_imported="defined"

	# WARNING: This variable is no longer used and should not be relied upon.
	# Use ${bash_preexec_imported} instead.
	# shellcheck disable=SC2034
	__bp_imported="${bash_preexec_imported}"

	# Should be available to each precmd and preexec
	# functions, should they want it. $? and $_ are available as $? and $_, but
	# $PIPESTATUS is available only in a copy, $BP_PIPESTATUS.
	# TODO: Figure out how to restore PIPESTATUS before each precmd or preexec
	# function.
	__bp_last_ret_value="$?"
	BP_PIPESTATUS=("${PIPESTATUS[@]}")
	__bp_last_argument_prev_command="$_"

	__bp_inside_precmd=0
	__bp_inside_preexec=0

	# Initial PROMPT_COMMAND string that is removed from PROMPT_COMMAND post __bp_install
	__bp_install_string=$'__bp_trap_string="$(trap -p DEBUG)"\ntrap - DEBUG\n__bp_install'

	# Fails if any of the given variables are readonly
	# Reference https://stackoverflow.com/a/4441178
	__bp_require_not_readonly() {
		local var
		for var; do
			if ! (unset "$var" 2>/dev/null); then
				echo "bash-preexec requires write access to ${var}" >&2
				return 1
			fi
		done
	}

	# Remove ignorespace and or replace ignoreboth from HISTCONTROL
	# so we can accurately invoke preexec with a command from our
	# history even if it starts with a space.
	__bp_adjust_histcontrol() {
		local histcontrol
		histcontrol="${HISTCONTROL:-}"
		histcontrol="${histcontrol//ignorespace/}"
		# Replace ignoreboth with ignoredups
		if [[ "$histcontrol" == *"ignoreboth"* ]]; then
			histcontrol="ignoredups:${histcontrol//ignoreboth/}"
		fi
		export HISTCONTROL="$histcontrol"
	}

	# This variable describes whether we are currently in "interactive mode";
	# i.e. whether this shell has just executed a prompt and is waiting for user
	# input.  It documents whether the current command invoked by the trace hook is
	# run interactively by the user; it's set immediately after the prompt hook,
	# and unset as soon as the trace hook is run.
	__bp_preexec_interactive_mode=""

	# These arrays are used to add functions to be run before, or after, prompts.
	declare -a precmd_functions
	declare -a preexec_functions

	# Trims leading and trailing whitespace from $2 and writes it to the variable
	# name passed as $1
	__bp_trim_whitespace() {
		local var=${1:?} text=${2:-}
		text="${text#"${text%%[![:space:]]*}"}" # remove leading whitespace characters
		text="${text%"${text##*[![:space:]]}"}" # remove trailing whitespace characters
		printf -v "$var" '%s' "$text"
	}

	# Trims whitespace and removes any leading or trailing semicolons from $2 and
	# writes the resulting string to the variable name passed as $1. Used for
	# manipulating substrings in PROMPT_COMMAND
	__bp_sanitize_string() {
		local var=${1:?} text=${2:-} sanitized
		__bp_trim_whitespace sanitized "$text"
		sanitized=${sanitized%;}
		sanitized=${sanitized#;}
		__bp_trim_whitespace sanitized "$sanitized"
		printf -v "$var" '%s' "$sanitized"
	}

	# This function is installed as part of the PROMPT_COMMAND;
	# It sets a variable to indicate that the prompt was just displayed,
	# to allow the DEBUG trap to know that the next command is likely interactive.
	__bp_interactive_mode() {
		__bp_preexec_interactive_mode="on"
	}

	# This function is installed as part of the PROMPT_COMMAND.
	# It will invoke any functions defined in the precmd_functions array.
	__bp_precmd_invoke_cmd() {
		# Save the returned value from our last command, and from each process in
		# its pipeline. Note: this MUST be the first thing done in this function.
		# BP_PIPESTATUS may be unused, ignore
		# shellcheck disable=SC2034

		__bp_last_ret_value="$?" BP_PIPESTATUS=("${PIPESTATUS[@]}")

		# Don't invoke precmds if we are inside an execution of an "original
		# prompt command" by another precmd execution loop. This avoids infinite
		# recursion.
		if ((__bp_inside_precmd > 0)); then
			return
		fi
		local __bp_inside_precmd=1

		# Invoke every function defined in our function array.
		local precmd_function
		for precmd_function in "${precmd_functions[@]}"; do

			# Only execute this function if it actually exists.
			# Test existence of functions with: declare -[Ff]
			if type -t "$precmd_function" 1>/dev/null; then
				__bp_set_ret_value "$__bp_last_ret_value" "$__bp_last_argument_prev_command"
				# Quote our function invocation to prevent issues with IFS
				"$precmd_function"
			fi
		done

		__bp_set_ret_value "$__bp_last_ret_value"
	}

	# Sets a return value in $?. We may want to get access to the $? variable in our
	# precmd functions. This is available for instance in zsh. We can simulate it in bash
	# by setting the value here.
	__bp_set_ret_value() {
		return ${1:+"$1"}
	}

	__bp_in_prompt_command() {

		local prompt_command_array IFS=$'\n;'
		read -rd '' -a prompt_command_array <<<"${PROMPT_COMMAND[*]:-}"

		local trimmed_arg
		__bp_trim_whitespace trimmed_arg "${1:-}"

		local command trimmed_command
		for command in "${prompt_command_array[@]:-}"; do
			__bp_trim_whitespace trimmed_command "$command"
			if [[ "$trimmed_command" == "$trimmed_arg" ]]; then
				return 0
			fi
		done

		return 1
	}

	# This function is installed as the DEBUG trap.  It is invoked before each
	# interactive prompt display.  Its purpose is to inspect the current
	# environment to attempt to detect if the current command is being invoked
	# interactively, and invoke 'preexec' if so.
	__bp_preexec_invoke_exec() {

		# Save the contents of $_ so that it can be restored later on.
		# https://stackoverflow.com/questions/40944532/bash-preserve-in-a-debug-trap#40944702
		__bp_last_argument_prev_command="${1:-}"
		# Don't invoke preexecs if we are inside of another preexec.
		if ((__bp_inside_preexec > 0)); then
			return
		fi
		local __bp_inside_preexec=1

		# Checks if the file descriptor is not standard out (i.e. '1')
		# __bp_delay_install checks if we're in test. Needed for bats to run.
		# Prevents preexec from being invoked for functions in PS1
		if [[ ! -t 1 && -z "${__bp_delay_install:-}" ]]; then
			return
		fi

		if [[ -n "${COMP_LINE:-}" ]]; then
			# We're in the middle of a completer. This obviously can't be
			# an interactively issued command.
			return
		fi
		if [[ -z "${__bp_preexec_interactive_mode:-}" ]]; then
			# We're doing something related to displaying the prompt.  Let the
			# prompt set the title instead of me.
			return
		else
			# If we're in a subshell, then the prompt won't be re-displayed to put
			# us back into interactive mode, so let's not set the variable back.
			# In other words, if you have a subshell like
			#   (sleep 1; sleep 2)
			# You want to see the 'sleep 2' as a set_command_title as well.
			if [[ 0 -eq "${BASH_SUBSHELL:-}" ]]; then
				__bp_preexec_interactive_mode=""
			fi
		fi

		if __bp_in_prompt_command "${BASH_COMMAND:-}"; then
			# If we're executing something inside our prompt_command then we don't
			# want to call preexec. Bash prior to 3.1 can't detect this at all :/
			__bp_preexec_interactive_mode=""
			return
		fi

		local this_command
		this_command=$(
			export LC_ALL=C
			HISTTIMEFORMAT='' builtin history 1 | sed '1 s/^ *[0-9][0-9]*[* ] //'
		)

		# Sanity check to make sure we have something to invoke our function with.
		if [[ -z "$this_command" ]]; then
			return
		fi

		# Invoke every function defined in our function array.
		local preexec_function
		local preexec_function_ret_value
		local preexec_ret_value=0
		for preexec_function in "${preexec_functions[@]:-}"; do

			# Only execute each function if it actually exists.
			# Test existence of function with: declare -[fF]
			if type -t "$preexec_function" 1>/dev/null; then
				__bp_set_ret_value "${__bp_last_ret_value:-}"
				# Quote our function invocation to prevent issues with IFS
				"$preexec_function" "$this_command"
				preexec_function_ret_value="$?"
				if [[ "$preexec_function_ret_value" != 0 ]]; then
					preexec_ret_value="$preexec_function_ret_value"
				fi
			fi
		done

		# Restore the last argument of the last executed command, and set the return
		# value of the DEBUG trap to be the return code of the last preexec function
		# to return an error.
		# If `extdebug` is enabled a non-zero return value from any preexec function
		# will cause the user's command not to execute.
		# Run `shopt -s extdebug` to enable
		__bp_set_ret_value "$preexec_ret_value" "$__bp_last_argument_prev_command"
	}

	__bp_install() {
		# Exit if we already have this installed.
		if [[ "${PROMPT_COMMAND[*]:-}" == *"__bp_precmd_invoke_cmd"* ]]; then
			return 1
		fi

		trap '__bp_preexec_invoke_exec "$_"' DEBUG

		# Preserve any prior DEBUG trap as a preexec function
		local prior_trap
		# we can't easily do this with variable expansion. Leaving as sed command.
		# shellcheck disable=SC2001
		prior_trap=$(sed "s/[^']*'\(.*\)'[^']*/\1/" <<<"${__bp_trap_string:-}")
		unset __bp_trap_string
		if [[ -n "$prior_trap" ]]; then
			eval '__bp_original_debug_trap() {
          '"$prior_trap"'
        }'
			preexec_functions+=(__bp_original_debug_trap)
		fi

		# Adjust our HISTCONTROL Variable if needed.
		__bp_adjust_histcontrol

		# Issue #25. Setting debug trap for subshells causes sessions to exit for
		# backgrounded subshell commands (e.g. (pwd)& ). Believe this is a bug in Bash.
		#
		# Disabling this by default. It can be enabled by setting this variable.
		if [[ -n "${__bp_enable_subshells:-}" ]]; then

			# Set so debug trap will work be invoked in subshells.
			set -o functrace >/dev/null 2>&1
			shopt -s extdebug >/dev/null 2>&1
		fi

		local existing_prompt_command
		# Remove setting our trap install string and sanitize the existing prompt command string
		existing_prompt_command="${PROMPT_COMMAND:-}"
		# Edge case of appending to PROMPT_COMMAND
		existing_prompt_command="${existing_prompt_command//$__bp_install_string/:}" # no-op
		existing_prompt_command="${existing_prompt_command//$'\n':$'\n'/$'\n'}"      # remove known-token only
		existing_prompt_command="${existing_prompt_command//$'\n':;/$'\n'}"          # remove known-token only
		__bp_sanitize_string existing_prompt_command "$existing_prompt_command"
		if [[ "${existing_prompt_command:-:}" == ":" ]]; then
			existing_prompt_command=
		fi

		# Install our hooks in PROMPT_COMMAND to allow our trap to know when we've
		# actually entered something.
		PROMPT_COMMAND='__bp_precmd_invoke_cmd'
		PROMPT_COMMAND+=${existing_prompt_command:+$'\n'$existing_prompt_command}
		if ((BASH_VERSINFO[0] > 5 || (BASH_VERSINFO[0] == 5 && BASH_VERSINFO[1] >= 1))); then
			PROMPT_COMMAND+=('__bp_interactive_mode')
		else
			# shellcheck disable=SC2179 # PROMPT_COMMAND is not an array in bash <= 5.0
			PROMPT_COMMAND+=$'\n__bp_interactive_mode'
		fi

		# Add two functions to our arrays for convenience
		# of definition.
		precmd_functions+=(precmd)
		preexec_functions+=(preexec)

		# Invoke our two functions manually that were added to $PROMPT_COMMAND
		__bp_precmd_invoke_cmd
		__bp_interactive_mode
	}

	# Sets an installation string as part of our PROMPT_COMMAND to install
	# after our session has started. This allows bash-preexec to be included
	# at any point in our bash profile.
	__bp_install_after_session_init() {
		# bash-preexec needs to modify these variables in order to work correctly
		# if it can't, just stop the installation
		__bp_require_not_readonly PROMPT_COMMAND HISTCONTROL HISTTIMEFORMAT || return

		local sanitized_prompt_command
		__bp_sanitize_string sanitized_prompt_command "${PROMPT_COMMAND:-}"
		if [[ -n "$sanitized_prompt_command" ]]; then
			# shellcheck disable=SC2178 # PROMPT_COMMAND is not an array in bash <= 5.0
			PROMPT_COMMAND=${sanitized_prompt_command}$'\n'
		fi
		# shellcheck disable=SC2179 # PROMPT_COMMAND is not an array in bash <= 5.0
		PROMPT_COMMAND+=${__bp_install_string}
	}

	# Run our install so long as we're not delaying it.
	if [[ -z "${__bp_delay_install:-}" ]]; then
		__bp_install_after_session_init
	fi

} # end of __wezterm_install_bash_prexec

# blesh provides it's own preexec mechanism which is recommended over bash-preexec
# See https://github.com/akinomyoga/ble.sh/wiki/Manual-%C2%A71-Introduction#user-content-fn-blehook for more details
if [[ ! -n "$BLE_VERSION" ]]; then
	__wezterm_install_bash_prexec
fi

# This function emits an OSC 1337 sequence to set a user var
# associated with the current terminal pane.
# It requires the `base64` utility to be available in the path.
__wezterm_set_user_var() {
	if hash base64 2>/dev/null; then
		if [[ -z "${TMUX}" ]]; then
			printf "\033]1337;SetUserVar=%s=%s\007" "$1" $(echo -n "$2" | base64)
		else
			# <https://github.com/tmux/tmux/wiki/FAQ#what-is-the-passthrough-escape-sequence-and-how-do-i-use-it>
			# Note that you ALSO need to add "set -g allow-passthrough on" to your tmux.conf
			printf "\033Ptmux;\033\033]1337;SetUserVar=%s=%s\007\033\\" "$1" $(echo -n "$2" | base64)
		fi
	fi
}

# This function emits an OSC 7 sequence to inform the terminal
# of the current working directory.  It prefers to use a helper
# command provided by wezterm if wezterm is installed, but falls
# back to a simple printf command otherwise.
__wezterm_osc7() {
	if hash wezterm 2>/dev/null; then
		wezterm set-working-directory 2>/dev/null && return 0
		# If the command failed (perhaps the installed wezterm
		# is too old?) then fall back to the simple version below.
	fi
	printf "\033]7;file://%s%s\033\\" "${HOSTNAME}" "${PWD}"
}

# The semantic precmd and prexec functions generate semantic
# zones, marking up the prompt, the user input and the command
# output so that the terminal can better reason about the display.
__wezterm_semantic_precmd_executing=""
__wezterm_semantic_precmd() {
	local ret="$?"
	if [[ "$__wezterm_semantic_precmd_executing" != "0" ]]; then
		__wezterm_save_ps1="$PS1"
		__wezterm_save_ps2="$PS2"
		# Markup the left and right prompts so that the terminal
		# knows that they are semantically prompt output.
		if [[ -n "$ZSH_NAME" ]]; then
			PS1=$'%{\e]133;P;k=i\a%}'$PS1$'%{\e]133;B\a%}'
			PS2=$'%{\e]133;P;k=s\a%}'$PS2$'%{\e]133;B\a%}'
		else
			PS1='\[\e]133;P;k=i\a\]'$PS1'\[\e]133;B\a\]'
			PS2='\[\e]133;P;k=s\a\]'$PS2'\[\e]133;B\a\]'
		fi
	fi
	if [[ "$__wezterm_semantic_precmd_executing" != "" ]]; then
		# Report last command status
		printf "\033]133;D;%s;aid=%s\007" "$ret" "$$"
	fi
	# Fresh line and start the prompt
	printf "\033]133;A;cl=m;aid=%s\007" "$$"
	__wezterm_semantic_precmd_executing=0
}

function __wezterm_semantic_preexec() {
	# Restore the original PS1/PS2
	PS1="$__wezterm_save_ps1"
	PS2="$__wezterm_save_ps2"
	# Indicate that the command output begins here
	printf "\033]133;C;\007"
	__wezterm_semantic_precmd_executing=1
}

__wezterm_user_vars_precmd() {
	__wezterm_set_user_var "WEZTERM_PROG" ""
	__wezterm_set_user_var "WEZTERM_USER" "$(id -un)"

	# Indicate whether this pane is running inside tmux or not
	if [[ -n "${TMUX}" ]]; then
		__wezterm_set_user_var "WEZTERM_IN_TMUX" "1"
	else
		__wezterm_set_user_var "WEZTERM_IN_TMUX" "0"
	fi

	# You may set WEZTERM_HOSTNAME to a name you want to use instead
	# of calling out to the hostname executable on every prompt print.
	if [[ -z "${WEZTERM_HOSTNAME}" ]]; then
		if hash hostname 2>/dev/null; then
			__wezterm_set_user_var "WEZTERM_HOST" "$(hostname)"
		elif hash hostnamectl 2>/dev/null; then
			__wezterm_set_user_var "WEZTERM_HOST" "$(hostnamectl hostname)"
		fi
	else
		__wezterm_set_user_var "WEZTERM_HOST" "${WEZTERM_HOSTNAME}"
	fi
}

__wezterm_user_vars_preexec() {
	# Tell wezterm the full command that is being run
	__wezterm_set_user_var "WEZTERM_PROG" "$1"
}

# Register the various functions; take care to perform osc7 after
# the semantic zones as we don't want to perturb the last command
# status before we've had a chance to report it to the terminal
if [[ -z "${WEZTERM_SHELL_SKIP_SEMANTIC_ZONES}" ]]; then
	if [[ -n "$BLE_VERSION" ]]; then
		blehook PRECMD+=__wezterm_semantic_precmd
		blehook PREEXEC+=__wezterm_semantic_preexec
	else
		precmd_functions+=(__wezterm_semantic_precmd)
		preexec_functions+=(__wezterm_semantic_preexec)
	fi
fi

if [[ -z "${WEZTERM_SHELL_SKIP_USER_VARS}" ]]; then
	if [[ -n "$BLE_VERSION" ]]; then
		blehook PRECMD+=__wezterm_user_vars_precmd
		blehook PREEXEC+=__wezterm_user_vars_preexec
	else
		precmd_functions+=(__wezterm_user_vars_precmd)
		preexec_functions+=(__wezterm_user_vars_preexec)
	fi
fi

if [[ -z "${WEZTERM_SHELL_SKIP_CWD}" ]]; then
	if [[ -n "$BLE_VERSION" ]]; then
		blehook PRECMD+=__wezterm_osc7
	else
		precmd_functions+=(__wezterm_osc7)
	fi
fi

true