380 lines
No EOL
14 KiB
Bash
380 lines
No EOL
14 KiB
Bash
# 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; |