Suggest stronger approach for saving/restoring files per pane

docs/restoring_bash_history.md

@@ -1,39 +1,89 @@
-tmux-ressurect no longer restores shell history for each pane, as of [this PR](https://github.com/tmux-plugins/tmux-resurrect/pull/308).
+tmux-resurrect no longer restores shell history for each pane, as of [this PR](https://github.com/tmux-plugins/tmux-resurrect/pull/308).
 
-As a workaround, you can use the `HISTFILE` environment variable to preserve history for each pane separately, and modify
-`PROMPT_COMMAND` to make sure history gets saved with each new command.
+As a workaround, you can use the `HISTFILE` environment variable to preserve history for each pane separately (and modifing
+`PROMPT_COMMAND` to make sure history gets saved with each new command), then use tmux-resurrect hooks to save/restore the histfile
 
-Unfortunately, we haven't found a perfect way of getting a unique identifier for each pane, as the `TMUX_PANE` variable
-seems to occasionally change when resurrecting. As a workaround, the example below sets a unique ID in each pane's `title`.
-The downside of this implementation is that pane titles must all be unique across sessions/windows, and also must use the `pane_id_prefix`.
+Add this to your .bashrc
+```bash
+# If in a TMUX pane, setup special history handling
+if [ -n "$TMUX_PANE" ]; then
+    # Pick a history directory and make sure it exists
+    HISTDIR=$HOME/.bash_history.d
+    mkdir -p "$HISTDIR"
+
+    # Set history file to a file using the TMUX pane id
+    export HISTFILE="${HISTDIR}/tmux_pane_${TMUX_PANE}"
+
+    # Setup so that after each command we:
+    # 1. Append current history to histfile
+    # 2. Clear current cached history info from memory
+    # 3. Read history from the histfile
+    export PROMPT_COMMAND="history -a;history -c;history -r;${PROMPT_COMMAND}"
+fi
+```
 
-Any improvements/suggestions for getting a unique, persistent ID for each pane are welcome!
+Then make some scripts (or merge into one, dealer's choice) to handle saving/restoring the histories.
+For this example, I'll assume you have these scripts placed in the root directory. Don't do that.
 
+post-save-all.sh
 ```bash
-pane_id_prefix="resurrect_"
+#!/usr/bin/env bash
 
-# Create history directory if it doesn't exist
-HISTS_DIR=$HOME/.bash_history.d
-mkdir -p "${HISTS_DIR}"
+RESURRECT_DIR="$HOME/.local/share/tmux/resurrect"
 
-if [ -n "${TMUX_PANE}" ]; then
+save_files() {
+    SAVE_DIR=$RESURRECT_DIR/$1
+    FILE_PREFIX=$2
 
-  # Check if we've already set this pane title
-  pane_id=$(tmux display -pt "${TMUX_PANE:?}" "#{pane_title}")
-  if [[ $pane_id != "$pane_id_prefix"* ]]; then
+    rm -r "$SAVE_DIR" 2>/dev/null
 
-    # if not, set it to a random ID
-    random_id=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 16)
-    printf "\033]2;$pane_id_prefix$random_id\033\\"
-    pane_id=$(tmux display -pt "${TMUX_PANE:?}" "#{pane_title}")
-  fi
+    for PANE_INFO in $(tmux list-panes -aF "#{pane_id}=#{session_id}:#{window_index}.#{pane_index}"); do
+        PANE_ID=$(echo $PANE_INFO | cut -f 1 -d'=' | cut -d% -f 2)
+        IN=${FILE_PREFIX}${PANE_ID}
+        if ! [[ -e "$IN" ]]; then continue; fi
 
-  # use the pane's random ID for the HISTFILE
-  export HISTFILE="${HISTS_DIR}/bash_history_tmux_${pane_id}"
-else
-  export HISTFILE="${HISTS_DIR}/bash_history_no_tmux"
-fi
+        PANE_INDEX=$(echo $PANE_INFO | cut -f 2 -d'=')
+        OUT=$SAVE_DIR/$PANE_INDEX
+        if [[ -e "$OUT" ]]; then rm -r "$OUT"; fi
+
+        mkdir -p $(dirname "$OUT")
+        cp -p -r "$IN" "$OUT"
+    done
+}
 
-# Stash the new history each time a command runs.
-export PROMPT_COMMAND="$PROMPT_COMMAND;history -a"
+save_files "history" "$HOME/.bash_history.d/tmux_pane_"
+```
+
+pre-restore-pane-processes.sh
+```bash
+#!/usr/bin/env bash
+
+RESURRECT_DIR="$HOME/.local/share/tmux/resurrect"
+
+restore_files() {
+    SAVE_DIR=$RESURRECT_DIR/$1
+    FILE_PREFIX=$2
+
+    for PANE_INFO in $(tmux list-panes -aF "#{pane_id}=#{session_id}:#{window_index}.#{pane_index}"); do
+        PANE_ID=$(echo $PANE_INFO | cut -f 1 -d'=' | cut -d% -f 2)
+        OUT=${FILE_PREFIX}${PANE_ID}
+        if [[ -e "$OUT" ]]; then rm -r "$OUT"; fi
+
+        PANE_INDEX=$(echo $PANE_INFO | cut -f 2 -d'=')
+        IN=$SAVE_DIR/$PANE_INDEX
+        if ! [[ -e "$IN" ]]; then continue; fi
+
+        mkdir -p $(dirname "$OUT")
+        cp --preserve -r "$IN" "$OUT"
+    done
+}
+
+restore_files "history" "$HOME/.bash_history.d/tmux_pane_"
+```
+
+Finally, add the following to your .tmux.conf
+```bash
+# Don't actually put these in the root folder!
+set -g @resurrect-hook-post-save-all "/post-save-all.sh"
+set -g @resurrect-hook-pre-restore-pane-processes "/pre-restore-pane-processes.sh"
 ```