Shell
calcdate: date arithmetic that doesn't make you cry
A Go CLI for date math, range generation, and timezone conversion with a readable expression syntax
Every shell scripter has, at some point, googled “date subtract day mac” or “GNU date macOS BSD difference” and wished they hadn’t. The date command is one of the most platform-fragmented tools in any Unix toolbox: GNU date and BSD date disagree on basically every flag that matters. And once you’ve worked out the syntax for “yesterday,” you still need to do something useful with it — like generate a range of timestamps for a backfill, or compute end-of-month, or skip weekends.
I got tired of this. So I wrote calcdate. Same binary on Linux, macOS, anywhere. One expression syntax. Version 2 just landed and the syntax is now genuinely pleasant to use.
retry: a tiny CLI for the things that almost always work
A Go CLI (and library) for retrying flaky commands with fixed delays or exponential backoff
There’s a category of bash one-liners I keep rewriting: “run this thing, and if it fails, try again a few times with a delay.” curl against a service that’s still booting. A kubectl rollout status that flickers. A flaky integration test. A docker pull from a registry having a bad five seconds.
You can write the loop yourself in five lines of bash. I’ve done it hundreds of times. But I always forget the exit code handling, the sleep arithmetic, the cap on retries. So I wrote retry — a single binary that does exactly this, with proper exponential backoff if you want it.
My IP from the Internet's view (shell)
Quick shell one-liners to find your public IP address using curl, dig, and a few alternatives — no browser required
Sometimes you just need to know what IP address the rest of the internet sees when your machine reaches out. Maybe you’re configuring a firewall rule, troubleshooting a VPN, or verifying that traffic is actually leaving through the tunnel you think it is.
No need to open a browser. A terminal is enough.