Shell

When you run a script as a systemd service, you have to define its environment variables in the service filem, e.g.

# Set your environment variables here
Environment="OJISAN_INCREMENTAL_UPLOAD_API_KEY=YOUR_ACTUAL_API_KEY_VALUE"
Environment="OJISAN_INCREMENTAL_UPLOAD_DB_USER=your_db_user"
Environment="OJISAN_INCREMENTAL_UPLOAD_DB_PW=your_db_password"
Environment="OJISAN_INCREMENTAL_UPLOAD_DB_NAME=your_db_name"
Environment="DB_HOST=your_db_host"

Show systemd running services as a list

systemctl list-units --type=service --state=running --no-pager

I was using a REST API at https://textance.herokuapp.com/title but it seems awfully fragile. Sure enough this morning, the entire application is down. It’s also not open-source and I have no idea who actually runs this thing.

Here’s the solution:

#!/bin/bash

url=$(pbpaste)
curl $url -so - | pup 'meta[property=og:title] attr{content}'

It does require pup. On macOS, you can install via brew install pup.

There are other ways using regular expressions but no dependency on pup but parsing HTML with regex is not such a good idea.

Introducing sterilize-ng [GitHub link] - a URL sterilizer made to work flexibily on the command line.

Background

The surveillance capitalist economy is built on the relentless tracking of users. Imagine going about town running errands but everywhere you go, someone is quietly following you. When you pop into the grocery, they examine your receipt. They look into the bags to see what you bought. Then they hop in the car with you and keep careful records of where you go, how fast you drive, whom you talk with on the phone. This is surveillance capitalism - the relentless “digital exhaust” left by our actions online.

A bunch of Unix date scripting things

Unix shell scripting is not one of my better-know areas of programming, but it’s on my list of things to learn. Some interesting bits about the date function.¹

1. Want the long date, like Thursday, January 28, 2021? → date +"%A, %B %d, %Y"
2. Want something like the above but with abbreviated month Thursday, Jan 28, 2021? → date +"%A, %b %d, %Y"
3. Time zone in the format of "-05:00" on macOS is:

#!/bin/bash

tz=$(date +"%z" | sd '(\d{2})(\d{2})' '$1:$2')
echo $tz

4. Long date in the format of 2021-01-28T05:30:48-05:00 that is use by Hugo²:

tz=$(date +"%z" | sd '(\d{2})(\d{2})' '$1:$2')
md_date=`date +"%Y-%m-%dT%H:%M:%S"`

5. Speaking of dates, this reference has very detailed information on date and time in the Unix shell.
6. Date in the format of 2021-01-28 is date +"%Y-%m-%d"

Unix slurp command output into a variable

In the UNIX shell, slurping the output of the command into a variable is done this way:³

As part of a Hazel rule to process downloaded mp3 files, I worked out a couple different methods for extracting the ID3 title tag. Not rocket science, but it took a little time to sort out. Both rely on non-standard third-party tools, both for parsing the text and for extracting the ID3 tags.

Extracting ID3 title with ffprobe

ffprobe is part of the ffmpeg suite of tools which on macOS can be installed with Homebrew. If you don’t have the latter, go install it now; because it opens up so many tools for your use. In this case, it makes ffmpeg available via brew install ffmpeg.

Since I’m not fond of carrying around all my photos on a cell phone where they’re perpetually at list of loss, I peridiocally dump the image and video files to a drive on my desktop for later burning to optical disc.¹ Saving these images in archival form is a hedge against the bet that my existing backup system won’t fail someday.

I’m using Blue-Ray optical discs to archive these image and video files; and each stores 25 GB of data. So my plan was to split the iPhone image dump into 24 GB partitions. H