Skip to content

Instantly share code, notes, and snippets.

@wryfi
Created December 5, 2016 16:50
Show Gist options
  • Save wryfi/41488c9345077878526e6633e77cb95d to your computer and use it in GitHub Desktop.
Save wryfi/41488c9345077878526e6633e77cb95d to your computer and use it in GitHub Desktop.
PY-21805
#!/bin/bash
# This is based on "preexec.bash" but is customized for iTerm2.
# Note: this module requires 2 bash features which you must not otherwise be
# using: the "DEBUG" trap, and the "PROMPT_COMMAND" variable. iterm2_preexec_install
# will override these and if you override one or the other this _will_ break.
# This is known to support bash3, as well as *mostly* support bash2.05b. It
# has been tested with the default shells on MacOS X 10.4 "Tiger", Ubuntu 5.10
# "Breezy Badger", Ubuntu 6.06 "Dapper Drake", and Ubuntu 6.10 "Edgy Eft".
# tmux and screen are not supported; even using the tmux hack to get escape
# codes passed through, ncurses interferes and the cursor isn't in the right
# place at the time it's passed through.
if [[ "$TERM" != screen && "$ITERM_SHELL_INTEGRATION_INSTALLED" = "" && "$-" == *i* ]]; then
ITERM_SHELL_INTEGRATION_INSTALLED=Yes
# Saved copy of your PS1. This is used to detect if the user changes PS1
# directly. ITERM_PREV_PS1 will hold the last value that this script set PS1 to
# (including various custom escape sequences).
ITERM_PREV_PS1="$PS1"
# 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.
ITERM_PREEXEC_INTERACTIVE_MODE=""
# Default do-nothing implementation of preexec.
function preexec () {
true
}
# Default do-nothing implementation of precmd.
function precmd () {
true
}
# This function is installed as the PROMPT_COMMAND; it is invoked before each
# interactive prompt display. It sets a variable to indicate that the prompt
# was just displayed, to allow the DEBUG trap, below, to know that the next
# command is likely interactive.
function iterm2_preexec_invoke_cmd () {
# Ideally we could do this in iterm2_preexec_install but CentOS 7.2 and
# RHEL 7.2 complain about bashdb-main.inc not existing if you do that
# (issue 4160).
# *BOTH* of these options need to be set for the DEBUG trap to be invoked
# in ( ) subshells. This smells like a bug in bash to me. The null stackederr
# redirections are to quiet errors on bash2.05 (i.e. OSX's default shell)
# where the options can't be set, and it's impossible to inherit the trap
# into subshells.
set -o functrace > /dev/null 2>&1
shopt -s extdebug > /dev/null 2>&1
\local s=$?
last_hist_ent="$(HISTTIMEFORMAT= builtin history 1)";
precmd;
# This is an iTerm2 addition to try to work around a problem in the
# original preexec.bash.
# When the PS1 has command substitutions, this gets invoked for each
# substitution and each command that's run within the substitution, which
# really adds up. It would be great if we could do something like this at
# the end of this script:
# PS1="$(iterm2_prompt_prefix)$PS1($iterm2_prompt_suffix)"
# and have iterm2_prompt_prefix set a global variable that tells precmd not to
# output anything and have iterm2_prompt_suffix reset that variable.
# Unfortunately, command substitutions run in subshells and can't
# communicate to the outside world.
# Instead, we have this workaround. We save the original value of PS1 in
# $ITERM_ORIG_PS1. Then each time this function is run (it's called from
# PROMPT_COMMAND just before the prompt is shown) it will change PS1 to a
# string without any command substitutions by doing eval on ITERM_ORIG_PS1. At
# this point ITERM_PREEXEC_INTERACTIVE_MODE is still the empty string, so preexec
# won't produce output for command substitutions.
# The first time this is called ITERM_ORIG_PS1 is unset. This tests if the variable
# is undefined (not just empty) and initializes it. We can't initialize this at the
# top of the script because it breaks with liquidprompt. liquidprompt wants to
# set PS1 from a PROMPT_COMMAND that runs just before us. Setting ITERM_ORIG_PS1
# at the top of the script will overwrite liquidprompt's PS1, whose value would
# never make it into ITERM_ORIG_PS1. Issue 4532. It's important to check
# if it's undefined before checking if it's empty because some users have
# bash set to error out on referencing an undefined variable.
if [ -z "${ITERM_ORIG_PS1+xxx}" ]
then
# ITERM_ORIG_PS1 always holds the last user-set value of PS1.
# You only get here on the first time iterm2_preexec_invoke_cmd is called.
export ITERM_ORIG_PS1="$PS1"
fi
if [[ "$PS1" != "$ITERM_PREV_PS1" ]]
then
export ITERM_ORIG_PS1="$PS1"
fi
# Get the value of the prompt prefix, which will change $?
\local iterm2_prompt_prefix_value="$(iterm2_prompt_prefix)"
# Reset $? to its saved value, which might be used in $ITERM_ORIG_PS1.
sh -c "exit $s"
# Set PS1 to various escape sequences, the user's preferred prompt, and more escape sequences.
export PS1="\[$iterm2_prompt_prefix_value\]$ITERM_ORIG_PS1\[$(iterm2_prompt_suffix)\]"
# Save the value we just set PS1 to so if the user changes PS1 we'll know and we can update ITERM_ORIG_PS1.
export ITERM_PREV_PS1="$PS1"
sh -c "exit $s"
# This must be the last line in this function, or else
# iterm2_preexec_invoke_exec will do its thing at the wrong time.
ITERM_PREEXEC_INTERACTIVE_MODE="yes";
}
# This function is installed as the DEBUG trap. It is invoked before each
# interactive prompt display. Its purpose is to inspect the current
# environment to attempt to detect if the current command is being invoked
# interactively, and invoke 'preexec' if so.
function iterm2_preexec_invoke_exec () {
if [ ! -t 1 ]
then
# We're in a piped subshell (STDOUT is not a TTY) like
# (echo -n A; sleep 1; echo -n B) | wc -c
# ...which should return "2".
return
fi
if [[ -n "${COMP_LINE:-}" ]]
then
# We're in the middle of a completer. This obviously can't be
# an interactively issued command.
return
fi
if [[ -z "$ITERM_PREEXEC_INTERACTIVE_MODE" ]]
then
# We're doing something related to displaying the prompt. Let the
# prompt set the title instead of me.
return
else
# If we're in a subshell, then the prompt won't be re-displayed to put
# us back into interactive mode, so let's not set the variable back.
# In other words, if you have a subshell like
# (sleep 1; sleep 2)
# You want to see the 'sleep 2' as a set_command_title as well.
if [[ 0 -eq "$BASH_SUBSHELL" ]]
then
ITERM_PREEXEC_INTERACTIVE_MODE=""
fi
fi
if [[ "iterm2_preexec_invoke_cmd" == "$BASH_COMMAND" ]]
then
# Sadly, there's no cleaner way to detect two prompts being displayed
# one after another. This makes it important that PROMPT_COMMAND
# remain set _exactly_ as below in iterm2_preexec_install. Let's switch back
# out of interactive mode and not trace any of the commands run in
# precmd.
# Given their buggy interaction between BASH_COMMAND and debug traps,
# versions of bash prior to 3.1 can't detect this at all.
ITERM_PREEXEC_INTERACTIVE_MODE=""
return
fi
# In more recent versions of bash, this could be set via the "BASH_COMMAND"
# variable, but using history here is better in some ways: for example, "ps
# auxf | less" will show up with both sides of the pipe if we use history,
# but only as "ps auxf" if not.
hist_ent="$(HISTTIMEFORMAT= builtin history 1)";
\local prev_hist_ent="${last_hist_ent}";
last_hist_ent="${hist_ent}";
if [[ "${prev_hist_ent}" != "${hist_ent}" ]]; then
\local this_command="$(echo "${hist_ent}" | sed -e "s/^[ ]*[0-9]*[ ]*//g")";
else
\local this_command="";
fi;
# If none of the previous checks have earlied out of this function, then
# the command is in fact interactive and we should invoke the user's
# preexec hook with the running command as an argument.
preexec "$this_command";
}
# Execute this to set up preexec and precmd execution.
function iterm2_preexec_install () {
# Finally, install the actual traps.
if ( [ x"${PROMPT_COMMAND:-}" = x ]); then
PROMPT_COMMAND="iterm2_preexec_invoke_cmd";
else
# If there's a trailing semicolon folowed by spaces, remove it (issue 3358).
PROMPT_COMMAND="$(echo -n $PROMPT_COMMAND | sed -e 's/; *$//'); iterm2_preexec_invoke_cmd";
fi
# The $_ is ignored, but prevents it from changing (issue 3932).
trap 'iterm2_preexec_invoke_exec "$_"' DEBUG;
}
# -- begin iTerm2 customization
function iterm2_begin_osc {
printf "\033]"
}
function iterm2_end_osc {
printf "\007"
}
# Runs after interactively edited command but before execution
function preexec() {
iterm2_begin_osc
printf "133;C;"
iterm2_end_osc
# If PS1 still has the value we set it to in iterm2_preexec_invoke_cmd then
# restore it to its original value. It might have changed if you have
# another PROMPT_COMMAND (like liquidprompt) that modifies PS1.
if [ -n "${ITERM_ORIG_PS1+xxx}" -a "$PS1" = "$ITERM_PREV_PS1" ]
then
export PS1="$ITERM_ORIG_PS1"
fi
iterm2_ran_preexec="yes"
}
function precmd () {
# Work around a bug in CentOS 7.2 where preexec doesn't run if you press
# ^C while entering a command.
if [[ -z "${iterm2_ran_preexec:-}" ]]
then
preexec ""
fi
iterm2_ran_preexec=""
}
function iterm2_print_state_data() {
iterm2_begin_osc
printf "1337;RemoteHost=%s@%s" "$USER" "$iterm2_hostname"
iterm2_end_osc
iterm2_begin_osc
printf "1337;CurrentDir=%s" "$PWD"
iterm2_end_osc
iterm2_print_user_vars
}
# Usage: iterm2_set_user_var key value
function iterm2_set_user_var() {
iterm2_begin_osc
printf "1337;SetUserVar=%s=%s" "$1" $(printf "%s" "$2" | base64)
iterm2_end_osc
}
if [ -z "$(type -t iterm2_print_user_vars)" ] || [ "$(type -t iterm2_print_user_vars)" != function ]; then
# iterm2_print_user_vars is not already defined. Provide a no-op default version.
#
# Users can write their own version of this function. It should call
# iterm2_set_user_var but not produce any other output.
function iterm2_print_user_vars() {
true
}
fi
function iterm2_prompt_prefix() {
iterm2_begin_osc
printf "133;D;\$?"
iterm2_end_osc
iterm2_print_state_data
iterm2_begin_osc
printf "133;A"
iterm2_end_osc
}
function iterm2_prompt_suffix() {
iterm2_begin_osc
printf "133;B"
iterm2_end_osc
}
function iterm2_print_version_number() {
iterm2_begin_osc
printf "1337;ShellIntegrationVersion=2;shell=bash"
iterm2_end_osc
}
# If hostname -f is slow on your system, set iterm2_hostname before sourcing this script.
if [ -z "${iterm2_hostname:-}" ]; then
iterm2_hostname=$(hostname -f)
fi
iterm2_preexec_install
# This is necessary so the first command line will have a hostname and current directory.
iterm2_print_state_data
iterm2_print_version_number
fi
alias imgcat=~/.iterm2/imgcat; alias it2dl=~/.iterm2/it2dl
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment