Feature: automatic history management

clean_files.txt

@@ -83,6 +83,7 @@ completion/available/wpscan.completion.bash
 # libraries
 lib/colors.bash
 lib/helpers.bash
+lib/history.bash
 lib/log.bash
 lib/preexec.bash
 lib/search.bash

lib/history.bash

@@ -0,0 +1,49 @@
+# shellcheck shell=bash
+#
+# Functions for working with Bash's command history.
+
+function _bash-it-history-init() {
+	safe_append_preexec '_bash-it-history-auto-save'
+	safe_append_prompt_command '_bash-it-history-auto-load'
+}
+
+function _bash-it-history-auto-save() {
+	case $HISTCONTROL in
+		*'noauto'* | *'autoload'*)
+			: # Do nothing, as configured.
+			;;
+		*'auto'*)
+			# Append new history from this session to the $HISTFILE
+			history -a
+			;;
+		*)
+			# Append *only* if shell option `histappend` has been enabled.
+			shopt -q histappend && history -a && return
+			;;
+	esac
+}
+
+function _bash-it-history-auto-load() {
+	case $HISTCONTROL in
+		*'noauto'*)
+			: # Do nothing, as configured.
+			;;
+		*'autosave'*)
+			# Append new history from this session to the $HISTFILE
+			history -a
+			;;
+		*'autoloadnew'*)
+			# Read new entries from $HISTFILE
+			history -n
+			;;
+		*'auto'*)
+			# Blank in-memory history, then read entire $HISTFILE fresh from disk.
+			history -a && history -c && history -r
+			;;
+		*)
+			: # Do nothing, default.
+			;;
+	esac
+}
+
+_bash_it_library_finalize_hook+=('_bash-it-history-init')

plugins/available/history-eternal.plugin.bash

@@ -1,20 +1,22 @@
 # shellcheck shell=bash
 about-plugin 'eternal bash history'
 
-# Load after the history plugin
-# BASH_IT_LOAD_PRIORITY: 375
+if [[ ${BASH_VERSINFO[0]} -lt 4 ]] || [[ ${BASH_VERSINFO[0]} -eq 4 && ${BASH_VERSINFO[1]} -lt 3 ]]; then
+	_log_warning "Bash version 4.3 introduced the 'unlimited' history size capability."
+	return 1
+fi
 
 # Modify history sizes before changing location to avoid unintentionally
 # truncating the history file early.
 
 # "Numeric values less than zero result in every command being saved on the history list (there is no limit)"
-export HISTSIZE=-1
+readonly HISTSIZE=-1 2> /dev/null || true
 
 # "Non-numeric values and numeric values less than zero inhibit truncation"
-export HISTFILESIZE='unlimited'
+readonly HISTFILESIZE='unlimited' 2> /dev/null || true
 
 # Use a custom history file location so history is not truncated
 # if the environment ever loses this "eternal" configuration.
 HISTDIR="${XDG_STATE_HOME:-${HOME?}/.local/state}/bash"
 [[ -d ${HISTDIR?} ]] || mkdir -p "${HISTDIR?}"
-export HISTFILE="${HISTDIR?}/history"
+readonly HISTFILE="${HISTDIR?}/history" 2> /dev/null || true

plugins/available/history-search.plugin.bash

@@ -1,9 +1,6 @@
 # shellcheck shell=bash
 about-plugin 'search history using the prefix already entered'
 
-# Load after the history plugin
-# BASH_IT_LOAD_PRIORITY: 375
-
 # enter a few characters and press UpArrow/DownArrow
 # to search backwards/forwards through the history
 if [[ ${SHELLOPTS} =~ (vi|emacs) ]]; then

plugins/available/history-substring-search.plugin.bash

@@ -1,9 +1,6 @@
 # shellcheck shell=bash
 about-plugin 'search history using the substring already entered'
 
-# Load after the history plugin
-# BASH_IT_LOAD_PRIORITY: 375
-
 # enter a few characters and press UpArrow/DownArrow
 # to search backwards/forwards through the history
 if [[ ${SHELLOPTS} =~ (vi|emacs) ]]; then

plugins/available/history.plugin.bash

@@ -5,14 +5,13 @@ about-plugin 'improve history handling with sane defaults'
 # variable when the shell exits, rather than overwriting the file.
 shopt -s histappend
 
-# erase duplicates; alternative option: export HISTCONTROL=ignoredups
-export HISTCONTROL=${HISTCONTROL:-ignorespace:erasedups}
+# 'ignorespace': don't save command lines which begin with a space to history
+# 'erasedups' (alternative 'ignoredups'): don't save duplicates to history
+# 'autoshare': automatically share history between multiple running shells
+: "${HISTCONTROL:=ignorespace:erasedups:autoshare}"
 
 # resize history to 100x the default (500)
-export HISTSIZE=${HISTSIZE:-50000}
-
-# Flush history to disk after each command.
-export PROMPT_COMMAND="history -a;${PROMPT_COMMAND}"
+: "${HISTSIZE:=50000}"
 
 function top-history() {
 	about 'print the name and count of the most commonly run tools'

themes/base.theme.bash

@@ -584,6 +584,7 @@ function aws_profile {
 }
 
 function _save-and-reload-history() {
-	local autosave=${1:-0}
-	[[ $autosave -eq 1 ]] && history -a && history -c && history -r
+	local autosave="${1:-${HISTORY_AUTOSAVE:-0}}"
+	[[ ${autosave} -eq 1 ]] && local HISTCONTROL="${HISTCONTROL:-}${HISTCONTROL:+:}autoshare"
+	_bash-it-history-auto-save && _bash-it-history-auto-load
 }