Tons and tons of them over the years. I wish I'd kept better track of them because I've caught myself reinventing the wheel now and again.
- When I was a kid using a DOS PC I'd write them in Microsoft QuickBASIC or Turbo Pascal and compile them to EXEs. (I used to drag a few particularly useful ones around with me until a few years ago when the prevalence of 64-bit Windows made running them on a stock Windows machine impossible.) I had stuff there like a random password generator, dumping files to VGA mode 13h (to visually look for patterns in data), drop the DTR on a serial port (to hang up a modem from the command line), search/replace on INI files, and lots of others I've forgotten.
- I wrote a proto-Markdown text processor back in high school when I was taking notes on a vTech Laser PC4[0]. It took files from the vTech and rendered output files with Epson printer formatting codes, centered text, made headings, etc.
- I regularly use a script I wrote to import my phone backups' SMS logs and dump them into my IMAP mailbox. I love being able to search all my email and SMS communication in the same interface.
- I have a podcatcher I wrote bolted onto my (heavily forked) tt-rss[1] installation to download podcasts to a local webserver for archiving and playing.
- My father persists in using a DOS accounting package for his business. A small program I wrote ingests check printing output from the DOS app (meant for dot matrix tractor-fed checks) and reformats it for sheet-fed checks in a laser printer.
- Front-end scripts for lots of command line utilities so that I don't have to remember obscure options for common tasks.
- When I was a kid using a DOS PC I'd write them in Microsoft QuickBASIC or Turbo Pascal and compile them to EXEs. (I used to drag a few particularly useful ones around with me until a few years ago when the prevalence of 64-bit Windows made running them on a stock Windows machine impossible.) I had stuff there like a random password generator, dumping files to VGA mode 13h (to visually look for patterns in data), drop the DTR on a serial port (to hang up a modem from the command line), search/replace on INI files, and lots of others I've forgotten.
- I wrote a proto-Markdown text processor back in high school when I was taking notes on a vTech Laser PC4[0]. It took files from the vTech and rendered output files with Epson printer formatting codes, centered text, made headings, etc.
- I regularly use a script I wrote to import my phone backups' SMS logs and dump them into my IMAP mailbox. I love being able to search all my email and SMS communication in the same interface.
- I have a podcatcher I wrote bolted onto my (heavily forked) tt-rss[1] installation to download podcasts to a local webserver for archiving and playing.
- My father persists in using a DOS accounting package for his business. A small program I wrote ingests check printing output from the DOS app (meant for dot matrix tractor-fed checks) and reformats it for sheet-fed checks in a laser printer.
- Front-end scripts for lots of command line utilities so that I don't have to remember obscure options for common tasks.
[0] https://oldcomputermuseum.com/laser_pc4.html
[1] https://tt-rss.org/