My name is Ian Fisher. I'm a software developer in New York City. In the wider world, I'm best known for creating CityQuiz.io, a geography quiz website. I write online, mainly but not entirely about software.
If you'd like to get in touch, send an email to my first name @ the name of this website.
Recent posts
- Why didn't the cron job succeed? (Dec 2024) – Some possible reasons your cron job did not do what you wanted it to.
- Unix file permissions cheatsheet (Nov 2024) – A cheatsheet of the Unix file permissions required for common operations, like creating, deleting, and renaming files.
- Whether you can access a path depends on how you name it (Nov 2024) – A surprising fact about Unix file permissions is that whether you are allowed to access a path depends on how you name it.
- What file permissions does mv need? (Nov 2024) – An explanation of the Unix file permissions that are required to run the 'mv' command.
- Be careful exporting from Postgres to SQLite (Nov 2024) – When exporting data from a Postgres database to import into SQLite, be aware that Postgres exports boolean columns in a different format than SQLite expects.
Favorites
- What file permissions does mv need? (Nov 2024) – An explanation of the Unix file permissions that are required to run the 'mv' command.
- Khaganate: a suite of personal productivity software (Feb 2022) – A description of my personal productivity system.
- A subtle garbage collector bug (Jul 2020) – My most memorable bug: a memory error in a hand-written mark-and-sweep garbage collector.
- Type-safe generic data structures in C (Jun 2020) – Techniques for writing generic data structures in C using pointer casts and code generation through macros.
- Writing an interpreter and debugger for an assembly language (May 2020) – The design and implementation of a toolkit for a pedagogical assembly language that included an interpreter, debugger and assembler and disassembler.