Per directory history plugin

plugins/per-directory-history/per-directory-history.plugin.zsh

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+#!/usr/bin/env zsh
+#
+# This is a implementation of per directory history for zsh, some 
+# implementations of which exist in bash[1,2].  It also implements 
+# a per-directory-history-toggle-history function to change from using the 
+# directory history to using the global history.  In both cases the history is 
+# always saved to both the global history and the directory history, so the 
+# toggle state will not effect the saved histories.  Being able to switch 
+# between global and directory histories on the fly is a novel feature as far 
+# as I am aware.
+#
+#-------------------------------------------------------------------------------
+# Configuration
+#-------------------------------------------------------------------------------
+#
+# HISTORY_BASE a global variable that defines the base directory in which the 
+# directory histories are stored
+#
+#-------------------------------------------------------------------------------
+# History
+#-------------------------------------------------------------------------------
+#
+# The idea/inspiration for a per directory history is from Stewart MacArthur[1] 
+# and Dieter[2], the implementation idea is from Bart Schaefer on the the zsh 
+# mailing list[3].  The implementation is by Jim Hester in September 2012.
+#
+# [1]: http://www.compbiome.com/2010/07/bash-per-directory-bash-history.html
+# [2]: http://dieter.plaetinck.be/per_directory_bash
+# [3]: http://www.zsh.org/mla/users/1997/msg00226.html
+#
+################################################################################
+#
+# Copyright (c) 2012 Jim Hester
+#
+# This software is provided 'as-is', without any express or implied warranty.  
+# In no event will the authors be held liable for any damages arising from the 
+# use of this software.
+#
+# Permission is granted to anyone to use this software for any purpose, 
+# including commercial applications, and to alter it and redistribute it 
+# freely, subject to the following restrictions:
+#
+# 1. The origin of this software must not be misrepresented; you must not claim 
+# that you wrote the original software. If you use this software in a product, 
+# an acknowledgment in the product documentation would be appreciated but is 
+# not required.
+#
+# 2. Altered source versions must be plainly marked as such, and must not be 
+# misrepresented as being the original software.
+#
+# 3. This notice may not be removed or altered from any source distribution..
+#
+################################################################################
+
+#-------------------------------------------------------------------------------
+# configuration, the base under which the directory histories are stored
+#-------------------------------------------------------------------------------
+
+[[ -z $HISTORY_BASE ]] && HISTORY_BASE="$HOME/.directory_history"
+
+#-------------------------------------------------------------------------------
+# toggle global/directory history used for searching - ctrl-G by default
+#-------------------------------------------------------------------------------
+
+function per-directory-history-toggle-history() {
+  if [[ $_per_directory_history_is_global == true ]]; then
+    _per-directory-history-set-directory-history
+    echo "using local history\n"
+  else
+    _per-directory-history-set-global-history
+    echo "using global history\n"
+  fi
+  zle reset-prompt
+}
+
+autoload per-directory-history-toggle-history
+zle -N per-directory-history-toggle-history
+bindkey '^G' per-directory-history-toggle-history
+
+#-------------------------------------------------------------------------------
+# implementation details
+#-------------------------------------------------------------------------------
+
+_per_directory_history_directory="$HISTORY_BASE${PWD:A}/history"
+
+function _per-directory-history-change-directory() {
+  _per_directory_history_directory="$HISTORY_BASE${PWD:A}/history"
+  mkdir -p ${_per_directory_history_directory:h}
+  if [[ $_per_directory_history_is_global == false ]]; then
+    #save to the global history
+    fc -AI $HISTFILE
+    #save history to previous file
+    local prev="$HISTORY_BASE${OLDPWD:A}/history"
+    mkdir -p ${prev:h}
+    fc -AI $prev
+
+    #discard previous directory's history
+    local original_histsize=$HISTSIZE
+    HISTSIZE=0
+    HISTSIZE=$original_histsize
+
+    #read history in new file
+    if [[ -e $_per_directory_history_directory ]]; then
+      fc -R $_per_directory_history_directory
+    fi
+  fi
+}
+
+function _per-directory-history-addhistory() {
+  print -sr -- ${1%%$'\n'}
+  fc -p $_per_directory_history_directory
+}
+
+
+function _per-directory-history-set-directory-history() {
+  if [[ $_per_directory_history_is_global == true ]]; then
+    fc -AI $HISTFILE
+    local original_histsize=$HISTSIZE
+    HISTSIZE=0
+    HISTSIZE=$original_histsize
+    if [[ -e "$_per_directory_history_directory" ]]; then
+      fc -R "$_per_directory_history_directory"
+    fi
+  fi
+  _per_directory_history_is_global=false
+}
+function _per-directory-history-set-global-history() {
+  if [[ $_per_directory_history_is_global == false ]]; then
+    fc -AI $_per_directory_history_directory
+    local original_histsize=$HISTSIZE
+    HISTSIZE=0
+    HISTSIZE=$original_histsize
+    if [[ -e "$HISTFILE" ]]; then
+      fc -R "$HISTFILE"
+    fi
+  fi
+  _per_directory_history_is_global=true
+}
+
+
+#add functions to the exec list for chpwd and zshaddhistory
+chpwd_functions=(${chpwd_functions[@]} "_per-directory-history-change-directory")
+zshaddhistory_functions=(${zshaddhistory_functions[@]} "_per-directory-history-addhistory")
+
+#start in directory mode
+mkdir -p ${_per_directory_history_directory:h}
+_per_directory_history_is_global=true
+_per-directory-history-set-directory-history