/etc/bashrc_Apple_Terminal

bashrc_Apple_Terminal.sh

# bash support for Terminal.


# Working Directory
#
# Tell the terminal about the current working directory at each prompt.

if [ -z "$INSIDE_EMACS" ]; then
    update_terminal_cwd() {
        # Identify the directory using a "file:" scheme URL, including
        # the host name to disambiguate local vs. remote paths.

        # Percent-encode the pathname.
        local url_path=''
        {
            # Use LC_CTYPE=C to process text byte-by-byte and
            # LC_COLLATE=C to compare byte-for-byte. Ensure that
            # LC_ALL and LANG are not set so they don't interfere.
            local i ch hexch LC_CTYPE=C LC_COLLATE=C LC_ALL='' LANG=''
            for ((i = 0; i < ${#PWD}; ++i)); do
                ch="${PWD:i:1}"
                if [[ "$ch" =~ [/._~A-Za-z0-9-] ]]; then
                    url_path+="$ch"
                else
                    printf -v hexch '%02X' "'$ch"
                    # printf treats values greater than 127 as
                    # negative and pads with "FF", so truncate.
                    url_path+="%${hexch: -2:2}"
                fi
            done
        }

        printf '\e]7;%s\a' "file://$HOSTNAME$url_path"
    }
    PROMPT_COMMAND=(update_terminal_cwd "${PROMPT_COMMAND[@]}")
fi


# Resume Support: Save/Restore Shell State
#
# Terminal assigns each terminal session a unique identifier and
# communicates it via the TERM_SESSION_ID environment variable so that
# programs running in a terminal can save/restore application-specific
# state when quitting and restarting Terminal with Resume enabled.
#
# The following code defines a shell save/restore mechanism. Users can
# add custom state by defining a shell_session_save_user_state function
# that writes restoration commands to the session file at exit. e.g.,
# to save a variable:
#
#   shell_session_save_user_state() { echo MY_VAR="'$MY_VAR'" >> "$SHELL_SESSION_FILE"; }
#
# During shell startup the session file is executed. Old files are
# periodically deleted.
#
# The default behavior arranges to save and restore the bash command
# history independently for each restored terminal session. It also
# merges commands into the global history for new sessions. Because
# of this it is recommended that you set HISTSIZE and HISTFILESIZE to
# larger values.
#
# You may disable this behavior and share a single history by setting
# SHELL_SESSION_HISTORY to 0. There are some common user customizations
# that arrange to share new commands among running shells by
# manipulating the history at each prompt, and they typically include
# 'shopt -s histappend'; therefore, if the histappend shell option is
# enabled, per-session history is disabled by default. You may
# explicitly enable it by setting SHELL_SESSION_HISTORY to 1.
#
# The implementation of per-session command histories in combination
# with a shared global command history is incompatible with the
# HISTTIMEFORMAT variable--the timestamps are applied inconsistently
# to different parts of the history; therefore, if HISTTIMEFORMAT is
# defined, per-session history is disabled by default.
#
# Note that this uses PROMPT_COMMAND to enable per-session history
# the first time for each new session. If you customize PROMPT_COMMAND
# be sure to include the previous value. e.g.,
#
#   PROMPT_COMMAND=(your_code_here "${PROMPT_COMMAND[@]}")
#
# Otherwise, the per-session history won't take effect until the first
# restore.
#
# The save/restore mechanism is disabled if the following file exists:
#
#   ~/.bash_sessions_disable

if [ "${SHELL_SESSION_DID_INIT:-0}" -eq 0 ] && [ -n "$TERM_SESSION_ID" ] && [ ! -e "$HOME/.bash_sessions_disable" ]; then

    # Do not perform this setup more than once (which shouldn't occur
    # unless the user's ~/.bash_profile executes /etc/profile, which
    # is normally redundant).
    SHELL_SESSION_DID_INIT=1

    # Set up the session directory/file.
    SHELL_SESSION_DIR="$HOME/.bash_sessions"
    SHELL_SESSION_FILE="$SHELL_SESSION_DIR/$TERM_SESSION_ID.session"
    mkdir -p "$SHELL_SESSION_DIR"
    chmod 700 "$SHELL_SESSION_DIR"

    #
    # Restore previous session state.
    #

    if [ -r "$SHELL_SESSION_FILE" ]; then
        # shellcheck disable=SC1090
        . "$SHELL_SESSION_FILE"
        rm "$SHELL_SESSION_FILE"
    fi

    #
    # Note: Use absolute paths to invoke commands in the exit code and
    # anything else that runs after user startup files, because the
    # search path may have been modified.
    #

    #
    # Arrange for per-session shell command history.
    #

    shell_session_history_allowed() {
        # Return whether per-session history should be enabled.
        if [ -n "$HISTFILE" ]; then
            # If this defaults to off, leave it unset so that we can
            # check again later. If it defaults to on, make it stick.
            local allowed=0
            if shopt -q histappend || [ -n "$HISTTIMEFORMAT" ]; then
                allowed=${SHELL_SESSION_HISTORY:-0}
            else
                allowed=${SHELL_SESSION_HISTORY:=1}
            fi
            if [ "$allowed" -eq 1 ]; then
                return 0
            fi
        fi
        return 1
    }

    if [ "${SHELL_SESSION_HISTORY:-1}" -eq 1 ]; then
        SHELL_SESSION_HISTFILE="$SHELL_SESSION_DIR/$TERM_SESSION_ID.history"
        SHELL_SESSION_HISTFILE_NEW="$SHELL_SESSION_DIR/$TERM_SESSION_ID.historynew"
        SHELL_SESSION_HISTFILE_SHARED="$HISTFILE"

        shell_session_history_enable() {
            (umask 077; /usr/bin/touch "$SHELL_SESSION_HISTFILE_NEW")
            HISTFILE="$SHELL_SESSION_HISTFILE_NEW"
            SHELL_SESSION_HISTORY=1
        }

        # If the session history already exists and isn't empty, start
        # using it now; otherwise, we'll use the shared history until
        # we've determined whether users have enabled/disabled this.
        if [ -s "$SHELL_SESSION_HISTFILE" ]; then
            history -r "$SHELL_SESSION_HISTFILE"
            shell_session_history_enable
        else
            # At the first prompt, check whether per-session history should
            # be enabled. Delaying until after user scripts have run allows
            # users to opt in or out. If this doesn't get executed (because
            # the user has replaced PROMPT_COMMAND instead of concatenating
            # it), we'll check at shell exit; that works, but doesn't start
            # the per-session history until the first restore.

            shell_session_history_check() {
                if [ "${SHELL_SESSION_DID_HISTORY_CHECK:-0}" -eq 0 ]; then
                    SHELL_SESSION_DID_HISTORY_CHECK=1
                    if shell_session_history_allowed; then
                        shell_session_history_enable
                    fi
                    # Remove this check if we can; otherwise, we rely on the
                    # variable above to prevent checking more than once.
                    if [[ " ${PROMPT_COMMAND[*]} " =~ [[:space:]]shell_session_history_check[[:space:]] ]]; then
                        PROMPT_COMMAND=( "${PROMPT_COMMAND[@]/shell_session_history_check}" )
                    fi
                fi
            }
            PROMPT_COMMAND=(shell_session_history_check "${PROMPT_COMMAND[@]}")
        fi

        shell_session_save_history() {
            # Save new history to an intermediate file so we can copy it.
            shell_session_history_enable
            history -a
            # If the session history doesn't exist yet, copy the shared history.
            if [ -f "$SHELL_SESSION_HISTFILE_SHARED" ] && [ ! -s "$SHELL_SESSION_HISTFILE" ]; then
                echo -ne '\n...copying shared history...' >&2
                (umask 077; /bin/cp "$SHELL_SESSION_HISTFILE_SHARED" "$SHELL_SESSION_HISTFILE")
            fi
            # Save new history to the per-session and shared files.
            echo -ne '\n...saving history...' >&2
            (umask 077; /bin/cat "$SHELL_SESSION_HISTFILE_NEW" >> "$SHELL_SESSION_HISTFILE_SHARED")
            (umask 077; /bin/cat "$SHELL_SESSION_HISTFILE_NEW" >> "$SHELL_SESSION_HISTFILE")
            : >| "$SHELL_SESSION_HISTFILE_NEW"
            # If there is a history file size limit, apply it to the files.
            if [ -n "$HISTFILESIZE" ]; then
                echo -n 'truncating history files...' >&2
                HISTFILE="$SHELL_SESSION_HISTFILE_SHARED"
                # shellcheck disable=SC2269
                HISTFILESIZE="$HISTFILESIZE"
                HISTFILE="$SHELL_SESSION_HISTFILE"
                # shellcheck disable=SC2269
                HISTFILESIZE="$HISTFILESIZE"
                HISTFILE="$SHELL_SESSION_HISTFILE_NEW"
            fi
            echo -ne '\n...' >&2
        }
    fi

    #
    # Arrange to save session state when exiting the shell.
    #

    shell_session_save() {
        # Save the current state.
        if [ -n "$SHELL_SESSION_FILE" ]; then
            echo -ne '\nSaving session...' >&2
            # shellcheck disable=SC2016
            (umask 077; echo 'echo Restored session: "$(/bin/date -r '"$(/bin/date +%s)"')"' >| "$SHELL_SESSION_FILE")
            declare -F shell_session_save_user_state >/dev/null && shell_session_save_user_state
            shell_session_history_allowed && shell_session_save_history
            echo 'completed.' >&2
        fi
    }

    # Delete old session files. (Not more than once a day.)
    SHELL_SESSION_TIMESTAMP_FILE="$SHELL_SESSION_DIR/_expiration_check_timestamp"
    shell_session_delete_expired() {
        if [ ! -e "$SHELL_SESSION_TIMESTAMP_FILE" ] || [ -z "$(/usr/bin/find "$SHELL_SESSION_TIMESTAMP_FILE" -mtime -1d)" ]; then
            local expiration_lock_file="$SHELL_SESSION_DIR/_expiration_lockfile"
            if /usr/bin/shlock -f "$expiration_lock_file" -p $$; then
                echo -n 'Deleting expired sessions...' >&2
                local delete_count=0
                delete_count="$(/usr/bin/find "$SHELL_SESSION_DIR" -type f -mtime +2w -print -delete | /usr/bin/wc -l)"
                [ "$delete_count" -gt 0 ] && echo "$delete_count completed." >&2 || echo 'none found.' >&2
                (umask 077; /usr/bin/touch "$SHELL_SESSION_TIMESTAMP_FILE")
                /bin/rm "$expiration_lock_file"
            fi
        fi
    }

    # Update saved session state when exiting.
    shell_session_update() {
        shell_session_save && shell_session_delete_expired
    }
    trap shell_session_update HUP EXIT
fi

Updated this script for modern bash (my version 5.2.26(1)-release).

Main change is the trap shell_session_update HUP EXIT which ensures that both exit and ⌘ + w and the terminal GUI close buttons all update the history.

Other changes include shellcheck cleanups and modern PROMPT_COMMAND array syntax.

Renamed the file to bashrc_Apple_Terminal.sh to get Gist syntax highlighting, but the real name is bashrc_Apple_Terminal.