From c741d1e3b5f14ac1f5b6e71305e82ee39569b413 Mon Sep 17 00:00:00 2001 From: Jan Pokorný Date: Thu, 20 Feb 2014 19:53:33 +0100 Subject: Bash config: auto-pagination trick for selected cmds (rpm, ...) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Jan Pokorný --- .bashrc | 27 +++++++- .bashrc-preexec | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 230 insertions(+), 1 deletion(-) create mode 100644 .bashrc-preexec diff --git a/.bashrc b/.bashrc index 1491d82..9b5045d 100644 --- a/.bashrc +++ b/.bashrc @@ -26,7 +26,9 @@ _linkalias () { linkalias () { alias "$1=_linkalias $2"; } # Source the other common definitions -for f in /etc/bashrc ~/.bashrc-dotfiles ~/.bashrc-fedora ~/.bashrc-work ~/.bashrc-xml ~/.bashrc-priv; do +_bashconfs="~/.bashrc-dotfiles ~/.bashrc-fedora ~/.bashrc-work ~/.bashrc-xml ~/.bashrc-priv ~/.bashrc-preexec" +for f in ${_bashconfs}; do + f=${f/#~/$HOME} [ -f "${f}" ] && source "${f}" || : done @@ -117,3 +119,26 @@ img-qr () { || { input=$(&1 | ${PAGER} + trap "_preexec_flag=0; trap - RETURN;" RETURN + return 2 + ;; + esac +} + +preexec_install diff --git a/.bashrc-preexec b/.bashrc-preexec new file mode 100644 index 0000000..8b035c5 --- /dev/null +++ b/.bashrc-preexec @@ -0,0 +1,204 @@ +#!/bin/bash + +# note by jpokorny: +# original http://www.twistedmatrix.com/users/glyph/preexec.bash.txt + +# preexec.bash -- Bash support for ZSH-like 'preexec' and 'precmd' functions. + +# The 'preexec' function is executed before each interactive command is +# executed, with the interactive command as its argument. The 'precmd' +# function is executed before each prompt is displayed. + +# To use, in order: + +# 1. source this file +# 2. define 'preexec' and/or 'precmd' functions (AFTER sourcing this file), +# 3. as near as possible to the end of your shell setup, run 'preexec_install' +# to kick everything off. + +# Note: this module requires 2 bash features which you must not otherwise be +# using: the "DEBUG" trap, and the "PROMPT_COMMAND" variable. preexec_install +# will override these and if you override one or the other this _will_ break. + +# This is known to support bash3, as well as *mostly* support bash2.05b. It +# has been tested with the default shells on MacOS X 10.4 "Tiger", Ubuntu 5.10 +# "Breezy Badger", Ubuntu 6.06 "Dapper Drake", and Ubuntu 6.10 "Edgy Eft". + + +# Copy screen-run variables from the remote host, if they're available. + +if [[ "$SCREEN_RUN_HOST" == "" ]] +then + SCREEN_RUN_HOST="$LC_SCREEN_RUN_HOST" + SCREEN_RUN_USER="$LC_SCREEN_RUN_USER" +fi + +# 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. +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 preexec_invoke_cmd () { + precmd + 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 preexec_invoke_exec () { + if [[ -n "$COMP_LINE" ]] + then + # We're in the middle of a completer. This obviously can't be + # an interactively issued command. + return + fi + if [[ -z "$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 "$BASH_SUBSHELL" ]] + then + preexec_interactive_mode="" + fi + fi + if [[ "preexec_invoke_cmd" == "$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 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. + 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. + local this_command=`history 1 | sed -e "s/^[ ]*[0-9]*[ ]*//g"`; + + # 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 "$this_command" +} + +# Execute this to set up preexec and precmd execution. +function preexec_install () { + + # *BOTH* of these options need to be set for the DEBUG trap to be invoked + # in ( ) subshells. This smells like a bug in bash to me. The null stderr + # redirections are to quiet errors on bash2.05 (i.e. OSX's default shell) + # where the options can't be set, and it's impossible to inherit the trap + # into subshells. + + set -o functrace > /dev/null 2>&1 + shopt -s extdebug > /dev/null 2>&1 + + # Finally, install the actual traps. + PROMPT_COMMAND="${PROMPT_COMMAND};preexec_invoke_cmd" + trap 'preexec_invoke_exec' DEBUG +} + +# Since this is the reason that 99% of everybody is going to bother with a +# pre-exec hook anyway, we'll include it in this module. + +# Change the title of the xterm. +function preexec_xterm_title () { + local title="$1" + echo -ne "\033]0;$title\007" > /dev/stderr +} + +function preexec_screen_title () { + local title="$1" + echo -ne "\033k$1\033\\" > /dev/stderr +} + +# Abbreviate the "user@host" string as much as possible to preserve space in +# screen titles. Elide the host if the host is the same, elide the user if the +# user is the same. +function preexec_screen_user_at_host () { + local RESULT="" + if [[ "$SCREEN_RUN_HOST" == "$SCREEN_HOST" ]] + then + return + else + if [[ "$SCREEN_RUN_USER" == "$USER" ]] + then + echo -n "@${SCREEN_HOST}" + else + echo -n "${USER}@${SCREEN_HOST}" + fi + fi +} + +function preexec_xterm_title_install () { + # These functions are defined here because they only make sense with the + # preexec_install below. + function precmd () { + preexec_xterm_title "${TERM} - ${USER}@${SCREEN_HOST} `dirs -0` $PROMPTCHAR" + if [[ "${TERM}" == screen ]] + then + preexec_screen_title "`preexec_screen_user_at_host`${PROMPTCHAR}" + fi + } + + function preexec () { + # xterm seems to treat backslashes funny; they terminate the escape + # sequence or something. I'm not sure why, but if we don't escape them + # by doubling them (like so) then running an interactive command with a + # backslash in it will result in a messed-up terminal and half a + # terminal title echoed onto the command line. + thiscmd="$(echo "$1" | sed -e 's/\\/\\\\/g' | head -n 1)" + preexec_xterm_title "${TERM} - $thiscmd {`dirs -0`} (${USER}@${SCREEN_HOST})" + if [[ "${TERM}" == screen ]] + then + local cutit="$1" + local cmdtitle=`echo "$cutit" | cut -d " " -f 1` + if [[ "$cmdtitle" == "exec" ]] + then + local cmdtitle=`echo "$cutit" | cut -d " " -f 2` + fi + if [[ "$cmdtitle" == "screen" ]] + then + # Since stacked screens are quite common, it would be nice to + # just display them as '$$'. + local cmdtitle="${PROMPTCHAR}" + else + local cmdtitle=":$cmdtitle" + fi + preexec_screen_title "`preexec_screen_user_at_host`${PROMPTCHAR}$cmdtitle" + fi + } + + preexec_install +} -- cgit