pj-append.bash

#!/usr/bin/env bash
set -e

# pj-append.bash is a timestamped log file for you, a human.  Set up a cron job to launch it every
# hour to note what you were working on, or append lines from the terminal whenever you're chewing
# on a hard problem.
#
# Use the data to build a picture of what you worked on during the last week, or grep
# last quarter's log to find out why you decided to use library A instead of library B.
#
# (pj = personal journal. Using alias pj="pj-append.bash" makes it quicker to use from the terminal)
#
# Writes timestamped lines of text to quarterly log files like pj-2020Q3.log.  The log files
# are automatically placed in the same directory as the script.
#
# Crontab looks like this:
# 0 * * * * <whatever-directory>/pj-append.bash
#
# Run without arguments from the terminal.  Whatever you type gets appended to the current
# log file.  You can also type "edit" to open a window to edit the current log file, or "tail"
# to print the last 10 lines.


# Change these to suit your preferences.  Note that the exact syntax needed here can vary
# from terminal to term
TERMINAL=/usr/bin/gnome-terminal
EDITOR=gedit

# Regex that gets matched against date "+%u.%H" to determine whether we're within working hours
# (if you only want the window to pop up during working hours)
WORKING_HOURS_REGEX="[1-5]\.(0[89]|1[0-7])"


# Following is a bunch of crap to detect if we're not in an interactive terminal
# (like, if we're in a cron job) and, if not, re-launch from inside an interactive terminal.
#
# 1 is stdin; -t tests if it's a vaild file descriptor.  If not, then that
# means we're not in an interactive terminal.
# http://stackoverflow.com/questions/911168/how-to-detect-if-my-shell-script-is-running-through-a-pipe
if [ ! -t 1 ]; then
    if ! [[ $(date "+%u.%H") =~ $WORKING_HOURS_REGEX ]]; then
        exit 0
    fi

    # Make sure there's a display to talk to
    # http://askubuntu.com/questions/202873/cron-cannot-run-gnome-terminal
    if [[ -z "$DISPLAY" ]]; then
        # :0 is usually the default display, except when it's not... so here's how we get it
        _user=$(id -un)
        export DISPLAY=$(w | sed -E "s/^${_user}[[:space:]]+(tty|:)[[:digit:]]+[[:space:]]+(:[[:digit:]]+) .*/\2/;t;d")
        if [[ -z "$DISPLAY" ]]; then
            echo "no currently active session; aborting"
            exit 1
        fi
    fi

    # Launching X apps needs DBUS_SESSION_BUS_ADDRESS too.  Luckily the format is very predictable
    # This might not always work, later on we might need
    # http://unix.stackexchange.com/questions/111188/using-notify-send-with-cron
    # ps -u 1000 x -o pid | while read p; do grep -az "^DBUS" /proc/$p/environ; done
    export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$(id -u)/bus"

    # relaunch in new environment. Note that the exact syntax needed here can vary from
    # terminal to terminal
    $TERMINAL -- "$0" "$@"

    exit
fi


_mydir=$(dirname $(readlink -f "$0"))

month=$(date +%m)
month=${month#0} # remove the leading zero so it's not interpreted as octal
quarter=$((($month - 1) / 3 + 1))
year=$(date +%Y)
logfile=$_mydir/pj-${year}Q${quarter}.log

timestamp=$(date +"%Y-%m-%d %H:%M:%S")
echo "What's up?"
# -e: allow editing (arrow keys, ctrl-backspace)
# -t: set timeout
read -e -t 300 what_is_up

if [[ "$what_is_up" = "edit" ]]; then
    setsid $EDITOR $logfile > /dev/null 2>&1 
    sleep .5
elif [[ "$what_is_up" = "tail" ]]; then
    echo ""
    tail -n 10 $logfile
else
    if [[ "$what_is_up" == "" ]]; then
        echo "You really should write something."
        read -t 300 what_is_up
    fi

    if [[ "$what_is_up" != "" ]]; then
        echo "$timestamp $what_is_up" >> $logfile
    fi
fi