memex – encrypted chronological note keeping tool for unix CLIs

Markus Konrad post@mkonrad.net, June 2022

Description

The memex tool is a bash script that can be used on almost any Unix-like OS for chronological note keeping on a day-by-day basis. It enables you to realize (daily) note keeping and recalling as described by Cory Doctorow, who in turn based his thoughts on the ideas of a "memory expanded" by Vannevar Bush, 1945.

Your notes will be encrypted with your private GPG key to keep them safe even when you store them in an untrusted environment (e.g. a cloud space or an unencrypted flash drive). Note however that reading and editing requires temporary storage of unencrypted data so you should read and write notes only in trusted environments.

Memex allows to periodically review past notes by retrieving notes from previous dates on fixed time-deltas, e.g. "one week ago", "one month ago", "one year ago", etc. to form a "powerful mnemonic" (Doctorow). You can also add attachments (i.e. any files like images, videos, etc.) to each day's note – these will also be encrypted.

Requirements

1. a Unix-like operating system with a bash shell and standard tools date, tar, grep, gpg, an editor like vim and optionally xdg-open if you want to open note attachments in a graphical environment
2. a gpg keypair; generate one if you haven't so far; keep note of the identity email used in your gpg keypair

Setup

• make sure the memex script file is executable (chmod +x memex)
• edit the memex script file to set the following variables right at the beginning of the script:
  • IDENT: identity email used in your gpg keypair
  • TMPDIR: local, trusted temporary folder; must be writable; unencrypted data will be written temporarily to this location and deleted after reading/writing
• memex will use your default editor specified by the EDITOR environment variable; if that's not given it will use vim; you can also hardcode an editor to use by editing the EDIT variable

Usage

Interact with memex using the commands described below. <...> denotes required arguments, [...] denotes optional arguments. The date argument is very important. It allows you to specify for which date you want to read or write a note. The way you specify that date is very flexible: You can specify the day in "year-month-day" format (e.g. "2022-06-29") or in a relative way, e.g. "2 days ago", "3 weeks ago" or "last friday". See the documentation for the Unix date utility for more information.

All data is stored in the sub-folder "memexdb", where each day has a folder named in the "year-month-day" (YYYY-MM-DD) format. Inside these folders the encrypted data is stored as YYYY-MM-DD.tar.gpg. The encrypted data contains at least one text note file named YYYY-MM-DD.txt and optional attachment files.

Commands

• ./memex or ./memex write [date] [attach]: create a new note or edit a note for "date" or today (default); if "attach" is given, open folder to add attachment files
• ./memex read [date]: if date is given, read the note at that date; else read notes for a sequence of past dates
• ./memex search <pattern>: search (encrypted) notes for a given grep pattern; this may take some time since all notes need to be decrypted one by one; decrypted data is directly piped to grep so no temporary unencrypted data is stored
• ./memex last: show the date of the last note that was taken
• ./memex encrypt: encrypt all note data in the memexdb that is not encrypted so far; the unencrypted notes must be named in the "YYYY-MM-DD.txt" format inside the respective days' folders; if all data is encrypted the command will not report anything

License

This project is licensed under MIT License. See LICENSE file for the full text.